Personal protective equipment (PPE) in veterinary practice serves two simultaneous purposes: protecting staff from patients, and protecting patients from staff and from each other.

Neither direction of protection can be neglected. Failure in either direction puts patients, staff, or the public at risk.

Quick answer: Veterinary PPE includes exam gloves, surgical gloves, bite-resistant gloves, masks, N95 respirators, gowns, and eye protection. Selection depends on the procedure, the patient's disease status, and splash or aerosol risk. Fewer than 40% of veterinary staff use appropriate PPE consistently.

Key takeaways

• Exam gloves are the baseline PPE for any patient contact involving bodily fluids, non-intact skin, feces, or mucous membranes
• Surgical gloves differ from exam gloves: they are sterile, thinner, and used only for sterile procedures
• Eye protection is required whenever splash is possible dental procedures, wound lavage, necropsy, and many laboratory procedures
• N95 respirators are required for aerosol-generating procedures in patients with suspected respiratory pathogens; surgical masks do not filter aerosols
• OSU CVM: fewer than 40% of veterinary staff use appropriate PPE consistently compliance is a recognized gap
• PPE removal sequence matters as much as donning sequence: incorrect removal contaminates skin and clothing

Why PPE compliance matters

OSU CVM: "Less than 40% of veterinarians and staff reported using the appropriate PPE for given situations."

OSU CVM: "When observing PPE removal by healthcare providers in one study, almost 50% inadvertently contaminated their skin or clothing."

OSU CVM: "Failure to properly use PPE puts you, your staff, and patients at increased risk for disease.

In some cases, disease outbreaks can occur in clinics and illness can be very severe, even leading to death."

PPE use is not optional for high-risk situations.

AVMA: "Drawing blood from a dog suspected or known to have leptospirosis poses greater biological health hazards than drawing blood from a clinically healthy dog.

The disease transmission risk warrants elevated caution and PPE."

Gloves: types and selection

Exam gloves (nitrile or latex)

The baseline barrier for general clinical work.

CVMA: "Nitrile gloves should be worn routinely when contact with feces, body fluids, vomitus, exudates, and non-intact skin is likely.

They should be worn when performing dental or obstetric procedures, resuscitations, and necropsies and when handling diagnostic specimens."

Nitrile is preferred over latex due to lower allergy risk for both staff and clients.

Indications:

• All patient examinations involving bodily fluids
• Wound assessment and dressing changes
• Handling fecal samples, urine, aspirates, or swabs
• Dental procedures (high splash risk)
• Any contact with animals of unknown infectious status

Surgical gloves

Sterile, powderless, and considerably thinner than exam gloves for tactile sensitivity. Used exclusively for sterile procedures.

Surgical gloves are donned using closed gloving technique after a full surgical scrub or ABHR. They are not interchangeable with exam gloves for sterile procedures.

Bite-resistant gloves

Mahan Law: "Staff members should have access to bite-resistant gloves for working with potentially fractious animals."

These are not sterile and not appropriate for aseptic work. They protect against puncture and laceration. They should be accessible in reception, examination rooms, and kennels.

Masks: surgical masks vs. N95 respirators

These two types of masks serve fundamentally different purposes and are not interchangeable.

Surgical masks

OSU CVM: "Face masks (surgical) are used to prevent exposure of the mucous membranes of the eyes, nose, and mouth to pathogens."

Surgical masks block large droplets and splatter. They are appropriate for:

• Routine surgical procedures (as part of full surgical attire)
• Procedures with splash risk to the mouth or nose
• General barrier between staff and patient

Surgical masks do not filter aerosols. They do not provide respiratory protection against airborne pathogens.

N95 respirators

N95 respirators filter at least 95% of airborne particles 0.3 microns or larger.

They are required when:

• A patient has confirmed or suspected airborne infectious disease (e.g., influenza, bordetella in kennel situations with active outbreak)
• Aerosol-generating procedures are performed on patients with respiratory pathogens
• Staff work in high-risk situations such as necropsy of animals with zoonotic pathogens

N95 respirators require fit testing to be effective. An N95 that does not fit correctly provides negligible protection over a surgical mask.

Eye and face protection

OSU CVM: "Face protection such as masks, goggles, and full-face shields prevent exposure of the mucous membranes of the eyes, nose, and mouth to pathogens."

OSU CVM: "These items are warranted whenever there is a risk for splashes or sprays onto a person's mucous membranes."

Situations requiring eye protection:

OSU CVM: "Items used for the above should be single-use disposable (surgical mask) or reusable after cleaned and disinfected (face shield, goggles)."

Protective outerwear: gowns, lab coats, and aprons

CVMA: "The purpose of protective outerwear is to limit the transfer of pathogens between the wearer and the patient, and to limit contamination of the wearer's clothing."

Lab coats:Baseline protection for routine clinical work. They prevent contamination of personal clothing and can be laundered. They are not fluid-resistant without specific coating.

Disposable gowns:Used for higher-risk situations: isolation cases, procedures with significant fluid exposure, or when the lab coat cannot be immediately changed between contaminated patients.

IndeVets: "Gowns/coveralls lab coats, cloth surgical gowns, change of scrubs, and even trash bags work in a pinch."

Sterile surgical gowns:Used exclusively for sterile surgical procedures. Not interchangeable with non-sterile disposable gowns.

Waterproof aprons:For procedures with heavy fluid volume necropsy, parturition, large wound irrigation.

PPE for specific high-risk situations

Isolation patients (suspected or confirmed contagious disease)

AVMA: patients with suspected leptospirosis warrant "double glove, face shields or the combination of masks and eye protection, disposable gown, isolation ward."

Full isolation PPE protocol:

• Disposable gown (new for each entry)
• Double gloves (outer pair removed on exit, inner pair with glove disposal)
• Goggles or face shield
• N95 if respiratory transmission is possible
• Dedicated footwear or disposable shoe covers

All PPE is removed before leaving the isolation area. AAHA Infection Control Guidelines specify a defined sequence: PPE is removed inside the room before touching the door handle.

Necropsy

CVMA: necropsy warrants full PPE due to "potential contact with infectious body fluids, aerosols, and contaminated sharps."

Full necropsy PPE: double gloves, face shield, gown or waterproof apron, N95 if respiratory pathogen is possible, cut-resistant gloves when opening body cavities in large animals.

Radiography

AVMA PPE list: "Lead-lined radiology thyroid guard, lead-lined radiology apron, radiology eyewear, lead-lined radiology gloves." These are not infection control items but physical hazard PPE required for radiation safety.

They require annual inspection and replacement when damaged.

PPE donning and removal sequence

Donning order: gown first, then mask/respirator, then eye protection, then gloves last.

Removal order is the reverse and equally critical. Gloves are removed first (the most contaminated item), then eye protection, then gown, then mask. Each step should avoid touching the contaminated outer surfaces.

OSU CVM: "Almost 50% of healthcare providers inadvertently contaminated their skin or clothing" during PPE removal. Removal should be practiced with deliberate attention until the sequence becomes automatic.

Hand hygiene at minimum, glove removal followed by hand washing or ABHR is performed after PPE removal is complete.

For the surgical scrubbing and sterile gloving that applies specifically to aseptic surgical procedures, see veterinary surgical hand scrub protocol. For isolation protocols for infectious patients, see isolation protocols for infectious dogs.

For aseptic technique in the operating room, see aseptic technique in dog and cat surgery.

Frequently asked questions

Do I need gloves for every patient interaction?

Not every interaction petting or walking a healthy dog does not require gloves.

Gloves are required when there is realistic risk of contact with bodily fluids, non-intact skin, feces, or mucous membranes, or when the patient's infectious status is unknown.

Can I reuse disposable gloves between patients if I use hand sanitizer on them?

No. Single-use gloves are designed for one patient contact. OSHA and AVMA guidelines do not support decontaminating and reusing exam gloves. A new pair is used for each patient.

My clinic does not have face shields. Can I use safety glasses instead?

Safety glasses without side panels provide minimal splash protection. OSU CVM specifies goggles that "wrap around the sides of the face or include side-protectors" as the appropriate choice.

Standard safety glasses are not equivalent to clinical goggles.

Are surgical masks sufficient for working with a dog that may have leptospirosis?

No. AVMA: leptospirosis-suspected dogs warrant "face shields or the combination of masks and eye protection." A surgical mask alone does not provide adequate protection for a high-risk zoonotic patient.

How often should PPE training be refreshed?

IndeVets recommends asking what PPE protocols are in place at any new practice and reviewing them on arrival. AVMA recommends regular refresher training.

Staff training at hiring and at least annually when protocols change is a reasonable minimum standard.

What PPE is needed when handling a dog with suspected parvovirus?

Full contact precautions: disposable gown and exam gloves (double-glove recommended), with eye protection if splash is possible.

Parvovirus is environmentally stable; PPE must be removed before leaving isolation, and contaminated surfaces must be disinfected with a parvocidal agent.

Resources

• AVMA. Personal Protective Equipment (PPE). avma.org
• OSU CVM. Types of PPE and Indications for Use Based on Risk Assessment. ohiostate.pressbooks.pub
• OSU CVM. Risk Assessment and Introduction to PPE Part 2. ohiostate.pressbooks.pub
• Mahan Law. Health and Safety Risks in Veterinary Practices. mahanlaw.com
• CVMA. Personal Protective Equipment. cvma-watchdog.net

TPLO is one of the most common surgical procedures in veterinary small animal practice. It is also one of the procedures with the highest reported SSI rates.

Published SSI rates for TPLO range from 0.8% to 14.3% in controlled cohort studies, with some reports citing complication rates as high as 28% including all post-operative issues. The procedure is classified as a clean surgery, meaning SSI rates should theoretically be at the lower end of the 1 to 5% range. That they frequently exceed this reflects the specific vulnerability this procedure creates.

What this covers: The TPLO-specific asepsis protocol, SSI risk factors unique to this procedure, intraoperative contamination management, the role of MRSP, and the evidence that stricter asepsis protocols reduce TPLO infection rates.Evidence base: 769-TPLO retrospective cohort (PMC10133455); DVM360 TPLO protocol improvement study (Stine et al., 703 dogs); PMC11946642 perioperative vs. extended antimicrobial study; intraoperative bacterial culture study (PMC11069177).Key clinical finding: Stine et al. (Vet Surg, 2018) demonstrated that implementing protocol changes to reduce implant-associated infection in TPLO produced a significantly lower IAI rate in the modified protocol period. The changes were predominantly asepsis-related, not antibiotic-related.

Key takeaways

• TPLO SSI rates (0.8 to 14.3%) exceed expected rates for a clean surgical class.
• MRSP colonization is an independent risk factor for TPLO SSI.
• The oscillating saw generates bone debris that contaminates the surgical field.
• Stricter asepsis protocols directly reduce TPLO implant-associated infection rates.
• Full-limb prep from groin to paw is required for TPLO procedures.
• Double gloving, strict OR traffic, and intraoperative lavage are standard for TPLO.
• Extended post-operative antibiotics do not reduce SSI rates; perioperative only suffices.

Why TPLO has elevated SSI rates

TPLO is a clean surgical procedure in a healthy dog. By wound classification standards, SSI rates should be 1 to 5%. The documented rates of 7 to 14% (and higher in some series) reflect procedure-specific factors:

1. Implant presence

TPLO uses a locking tibial plate and screws. As with all implant procedures, the presence of foreign material dramatically lowers the minimum infective dose required to establish infection and provides a substrate for biofilm formation.

2. Oscillating saw contamination

The circular osteotomy requires an oscillating saw operating at high speed. This generates:

• Aerosolized bone and marrow contents that settle on the sterile field
• Localized thermal damage to bone and soft tissue that reduces local tissue viability
• Blood and tissue debris that accumulates in the wound and surgical field

Saline irrigation during saw use reduces thermal damage and debris generation. Still, the amount of intraoperative contamination in TPLO exceeds most other clean procedures.

3. Prolonged procedure time

TPLO typically takes 90 minutes or more including arthrotomy, meniscal assessment, osteotomy, and plating. Longer procedures accumulate more contamination opportunities and place sustained demands on OR traffic and sterile field management.

4. MRSP colonization rate in stifle patients

Pre-operative MRSP carrier status has been identified as a significant independent risk factor for TPLO SSI in multiple cohort studies. The MRSP carrier rate in dogs undergoing stifle surgery may be higher than in the general canine population due to prior antibiotic exposure and skin disease that often co-exists with cruciate ligament disease.

5. Sparse soft tissue coverage of the proximal tibia

The medial proximal tibia has thin soft tissue coverage. This creates a challenging wound closure with limited tissue depth between the implant and the skin surface, shortening the distance bacteria must traverse to reach the implant.

The TPLO-specific asepsis protocol

Pre-operative preparation

Patient assessment:

Pre-operative MRSP screening is increasingly supported for TPLO candidates, particularly those with:

• Prior history of skin infection, ear infection, or dermatitis
• Prior antimicrobial treatment within the past three to six months
• Previous SSI at any site
• Known prior MRSP colonization

Clipping:

Clip the entire operated limb from the inguinal region to the distal tarsus. The entire limb clip allows full circumferential draping and access for skin prep to all surfaces that will be manipulated during hanging-limb preparation.

Skin antisepsis (hanging-limb method):

DVM360 documents the modified TPLO protocol at a North Carolina referral center that reduced IAI rates as including: "hanging-limb asepsis with alternating chlorhexidine gluconate solution and alcohol, followed by alternating chlorhexidine and sterile saline."

Standard approach:

1. Limb suspended in a sterile stockinette or loop
2. Three-pass minimum centrifugal scrub sequence: CHG scrub, alcohol, CHG solution
3. Full coverage of the entire clipped limb
4. Allow full evaporation before draping

Antimicrobial prophylaxis:

Cefazolin 22 mg/kg IV administered 30 to 60 minutes before incision. Repeated every 90 to 120 minutes intraoperatively for procedures exceeding that interval.

Published evidence (PMC11946642) confirms that perioperative antimicrobial administration alone (without post-operative extension) maintains acceptable SSI rates in TPLO. Extended post-operative antibiotic courses do not reduce SSI rates further and contribute to antimicrobial resistance.

Standard prophylaxis does not cover MRSP. Asepsis is the primary MRSP prevention strategy.

Intraoperative technique

Draping:

Circumferential draping of the limb using sterile stockinette and impervious drapes. The entire limb within the sterile field must be draped such that only the surgical site is exposed.

Double gloving:

Mandatory for all TPLO procedures. Bone work, wire handling, and plate manipulation create multiple glove perforation opportunities. The inner glove provides a second barrier that is typically maintained even when the outer glove is perforated.

OR traffic restriction:

TPLO procedures should have the strictest OR traffic protocol of any procedure in the practice. Pre-operative supply confirmation eliminates the most common reason for door openings during the case. No non-essential personnel should enter during the procedure.

Saw irrigation:

During the circular osteotomy, continuous or pulsed irrigation with sterile saline:

• Reduces thermal damage to the osteotomy site
• Reduces aerosolized bone debris contamination of the sterile field
• Removes blood and tissue debris from the cut surface

Implant handling:

• Plate and screws remain in sterile packaging until immediately before use
• Transferred to the sterile field using sterile technique
• Never contact non-sterile surfaces at any point
• If any implant component is contaminated, it is replaced with a new sterile component

Intraoperative lavage before closure:

Copious saline lavage (minimum 500 mL) after plate application and before closure removes:

• Bone debris from the osteotomy
• Blood clots from the operative field
• Free-floating bacteria accumulated during surgery

For TPLO specifically, where MRSP and biofilm-forming organisms are the primary SSI concern, antiseptic lavage before closure has been used to address residual contamination that saline alone does not eliminate. Non-antibiotic antiseptic lavage options targeting resistant organisms and biofilm have been used in this context.

For implant-specific asepsis during TPLO, including the full rationale for enhanced asepsis in implant procedures and the specific implant handling standards, that guide covers the implant asepsis context.

The intraoperative technique standards that govern the sterile field, double gloving execution, and instrument handling during TPLO are covered in the broader aseptic technique framework. For core aseptic technique applied in TPLO, including the sterile field rules, instrument passing protocol, and technique violation response framework that apply during all surgical procedures, that guide covers the intraoperative technique standard.

Evidence that stricter asepsis reduces TPLO SSI

The DVM360 report of the Stine et al. (Vet Surg, 2018) study at a North Carolina referral center compared 703 dogs and 811 TPLO procedures across two protocol periods:

• Standard protocol period (2006 to 2008): baseline IAI rate
• Modified protocol period (2011 to 2014): stricter asepsis protocol implemented

The modified protocol changes included enhanced skin preparation technique, stricter OR traffic management, and protocol standardization. The IAI rate in the modified protocol period was significantly lower than in the standard period.

This is direct evidence that asepsis protocol changes, not antibiotic changes, drive TPLO SSI rate improvement.

For MRSP prevention through TPLO asepsis, including why MRSP is the dominant SSI pathogen in TPLO cases and how asepsis-based prevention addresses this specifically, that guide covers the MRSP dimension.

Post-operative monitoring for TPLO patients

Monitoring schedule:

• 48 to 72 hour wound check
• Suture/staple removal at 14 days
• Radiographic recheck at 6 to 8 weeks for osteotomy healing assessment
• Full weight-bearing assessment at 10 to 12 weeks

What to monitor:

• Incision: redness, swelling, discharge, warmth
• Systemic signs: fever, lethargy, reduced appetite
• Limb use: sudden non-weight-bearing is the most common sign of deep implant infection

SSI window:

TPLO SSI can develop immediately post-operatively (intraoperative contamination) or weeks to months later (delayed biofilm maturation or hematogenous seeding). Any non-weight-bearing episode in the weeks following a resolved TPLO should prompt veterinary evaluation for late SSI.

For broader orthopedic surgery asepsis in dogs, including the full perioperative asepsis protocol for all canine orthopedic procedures and how TPLO-specific requirements fit within the broader orthopedic asepsis standard, that guide covers the full orthopedic context.

Frequently asked questions

Why is TPLO SSI rate higher than expected for a clean procedure?

Several TPLO-specific factors elevate SSI risk beyond the clean wound class baseline: implant presence reducing the minimum infective dose; oscillating saw contamination; prolonged procedure time; MRSP colonization prevalence in stifle patients; and the thin soft tissue coverage over the proximal tibial plate. These factors make TPLO one of the highest-SSI-risk clean procedures in veterinary surgery.

Does MRSP screening change the surgical plan for TPLO?

MRSP-positive dogs may benefit from targeted decolonization protocols before elective TPLO, enhanced intraoperative asepsis, and post-operative monitoring. For urgent or non-elective cases in MRSP-positive dogs, heightened intraoperative asepsis including antiseptic lavage is particularly important. Consult current veterinary dermatology guidelines for decolonization protocols.

Is post-operative antibiotic prophylaxis required after TPLO?

Current evidence does not support extended post-operative antibiotic prophylaxis for TPLO in dogs without specific risk factors. PMC11946642 found no SSI rate difference between perioperative-only and peri-plus-postoperative antimicrobial groups. Perioperative prophylaxis timed correctly, combined with strict asepsis, represents the evidence-based standard.

For surgical asepsis standards that provide the comprehensive perioperative asepsis framework within which TPLO-specific requirements operate, that guide covers the full five-domain surgical asepsis standard.

TPLO SSI rates are higher than they should be for a clean procedure, and published evidence confirms that stricter asepsis protocols reduce them. The intervention that drives improvement is not the antibiotic choice. It is the combination of correct skin preparation, strict OR traffic control, full-limb draping, implant handling discipline, and intraoperative lavage that constitutes enhanced TPLO asepsis.

Resources

The following sources were used as reference and background for this article:

• NIH/PMC. Surgical site infection after 769 Tibial Plateau Leveling Osteotomies. pmc.ncbi.nlm.nih.gov
• DVM360. Improving Infection Rates After TPLO. dvm360.com
• NIH/PMC. Comparison of SSI Rates in TPLO Using Perioperative vs. Extended Antimicrobial Prophylaxis. ncbi.nlm.nih.gov
• NIH/PMC. Clinical relevance of positive intraoperative bacterial culture in TPLO in dogs. ncbi.nlm.nih.gov
• Veterinary Practice News. Old and New Thoughts on Infection Control. veterinarypracticenews.com

Biofilm is one of the most clinically significant challenges in veterinary surgical infections, and one of the least understood by pet owners and many non-specialist clinicians.

When bacteria form a biofilm on a surgical implant or in a wound, they enter a fundamentally different biological state from free-floating bacteria. Standard antibiotics, immune cells, and antiseptics that would eliminate the same bacteria in their planktonic (free-floating) state often fail to penetrate the biofilm matrix. This is why implant-associated infections are so difficult to resolve and why prevention matters enormously.

Quick answer: Biofilm is a community of bacteria embedded in a self-produced protective matrix that adheres to surfaces including orthopedic implants, suture material, and wound tissue. Once established, biofilm dramatically reduces antibiotic penetration and immune cell access, often making implant removal the only curative option. Prevention focuses on reducing bacterial load before biofilm can establish: meticulous sterile technique, intraoperative lavage, antibiotic prophylaxis, and prompt recognition of early infection.

Key takeaways

• Biofilm bacteria are 100 to 1,000 times more resistant to antibiotics than the same bacteria in planktonic form.
• Orthopedic implants are the highest-risk surface for biofilm formation in veterinary surgery.
• Once biofilm establishes on an implant, removal is often the only curative option.
• MRSP is a particularly prolific biofilm former among canine surgical pathogens.
• Prevention is far more effective than treatment: the window for intervention is intraoperative.
• SSI rates of 0.8% to 21.3% in canine surgery reflect wide variation in biofilm-relevant protocol quality.

What is biofilm and why is it so difficult to treat?

Biofilm is not simply a colony of bacteria. It is a structured community of microorganisms enclosed in an extracellular polymeric substance (EPS), a "slimy" matrix composed of polysaccharides, proteins, DNA, and lipids that the bacteria themselves produce.

The Veterinary Nurse explains: "Mature biofilms are very effective at protecting their embedded microorganisms. The formation of the EPS means these now-colonised microorganisms can become highly resistant to the body's natural immune response and external environmental factors, such as traditional biocides (antibiotics, antiseptics, and disinfectants) that would usually be effective at destroying the same microorganisms living in a planktonic state as free-floating single organisms."

The four stages of biofilm formation

1. Initial adhesion: planktonic bacteria attach loosely to a surface (implant, tissue, or suture material)
2. Irreversible attachment: bacteria anchor firmly and begin producing EPS
3. Microcolony formation: bacteria multiply within the developing matrix
4. Maturation: the biofilm reaches its full structure; bacteria within are now protected from antibiotics and immune cells
5. Dispersal: biofilm periodically releases planktonic bacteria that can seed new infection sites

The critical point: prevention is only possible before stage 2. Once irreversible attachment occurs, eradication without implant removal becomes extremely difficult.

Why biofilm matters in veterinary orthopedic surgery

The intersection of biofilm biology and veterinary orthopedic surgery creates a uniquely difficult clinical problem.

Clinician's Brief identifies orthopedic implants as a primary biofilm-associated infection site: "Common causes of biofilm-associated infection include orthopedic implant infections, often caused by Staphylococcus pseudintermedius and other gram-positive pathogens."

The economic impact is substantial. Clinician's Brief reports: "A recent study in dogs showed the economic impact of surgical site infections after TPLO surgery to be $110.21 to $3,817.12 USD."

Why implant removal is often unavoidable

When biofilm establishes on an orthopedic implant (TPLO plate, THR prosthesis, fracture fixation hardware), the EPS matrix prevents antibiotics from reaching adequate concentrations at the infection site. Clinician's Brief confirms: "Orthopedic implant infections associated with a biofilm can be difficult to treat because biofilms inhibit penetration of antimicrobials and cells of the immune system. In many cases of biofilm-associated implant infections, implant removal is often the only choice for eliminating the biofilm."

When bone healing is not yet complete at the time of infection, this creates a clinical dilemma: the implant must stay for structural support, but it maintains the infection. Clinician's Brief notes: "Fractures can heal in the presence of a biofilm infection if there is sufficient stability; however, delayed healing can occur."

For how MRSP biofilm forms specifically in post-surgical cases, see MRSP biofilm formation after TPLO and other surgeries.

Which organisms form biofilm in veterinary surgical infections?

The most clinically significant biofilm-forming pathogens in veterinary orthopedic surgery:

MRSP is of particular concern because resistance to multiple antibiotic classes means fewer treatment options are available even if the biofilm could be penetrated.

Biofilm prevention: the intraoperative window

Prevention is the only reliable strategy. The goal is to prevent the initial bacterial adhesion that starts the biofilm cascade.

Reducing bacterial load in the wound

Every measure that reduces bacterial numbers at the operative site before wound closure reduces the probability that adhesion will occur at a scale sufficient to establish biofilm.

Sterile technique: Iodophore-impregnated drapes, orthopedic gloves, and rigorous instrument handling reduce environmental and skin-flora contamination of the wound and implant surfaces.

Antibiotic prophylaxis: Cefazolin given 30 to 60 minutes before incision reaches tissue concentrations that impair bacterial survival during the early adhesion window. This is the key moment: antibiotics are most effective against planktonic bacteria before biofilm establishes.

Intraoperative lavage: Saline lavage before wound closure physically removes planktonic bacteria and tissue debris from the operative site. Removing the bacterial substrate directly reduces the pool from which biofilm can form.

Antiseptic irrigation

Beyond saline, antiseptic irrigation solutions with broad-spectrum antibacterial activity and the ability to disrupt developing biofilm have been studied in veterinary surgery. The Veterinary Nurse notes that polyhexamethylene biguanide (PHMB)-based lavage solutions have gained attention for use in biofilm-associated wounds, citing broad-spectrum activity and low tissue toxicity.

Implant surface technology

Research continues into implant coatings that inhibit bacterial adhesion. Clinician's Brief references a study evaluating silver-impregnated coating to inhibit colonization of orthopedic implants by biofilm-forming MRSP. Evidence remains evolving, and no single coating has achieved universal adoption in veterinary practice.

For how surface disinfection in the hospital environment supports biofilm prevention, see surface disinfection to prevent biofilm formation.

Recognizing early biofilm-associated infection

Biofilm-associated implant infections often present differently from straightforward wound infections. Recognizing the pattern enables earlier intervention:

• Delayed onset: implant infections often appear weeks after surgery, not in the immediate post-operative period
• Subtle early signs: mild intermittent lameness, slight swelling at the implant site, without obvious wound breakdown
• Poor response to standard antibiotics: the infection appears to improve then relapse despite completing an antibiotic course
• Recurring drainage: a draining tract from the implant site that recurs after temporary improvement with antibiotics is a classic biofilm infection presentation

Any post-surgical infection that doesn't respond as expected to first-line antibiotics warrants culture and sensitivity testing, imaging to assess the implant, and specialist consultation.

For antibiotics that specifically address biofilm-related infections and their limitations, see antibiotics that address biofilm-related infections.

What owners can do

Owners don't control intraoperative technique, but they control the post-operative environment where early biofilm-forming infections most often become clinical:

• E-collar compliance: prevents licking from introducing bacteria that can establish at the implant site
• Activity restriction: reduces mechanical stress that can disrupt wound integrity and create new bacterial entry points
• Early reporting: the most impactful owner action is notifying the vet promptly when something seems off, before a small implant infection matures into an established biofilm infection requiring hardware removal

For the full SSI prevention framework that supports biofilm prevention, see SSI prevention that biofilm prevention supports. For biofilm risk specifically in the context of orthopedic surgery, see biofilm risk in orthopedic surgery.

Frequently asked questions

Can you treat a biofilm infection without removing the implant?

Sometimes, but not reliably. Antibiotic therapy can suppress clinical signs while biofilm remains on the implant, creating a cycle of temporary improvement and relapse. If the implant is not yet supporting a healing fracture, earlier removal gives the infection the best chance of resolution. For implants that cannot be removed (THR prostheses mid-healing), debridement irrigation procedures may be attempted, but success rates are lower than for infections detected before biofilm matures.

How quickly does biofilm form on a surgical implant?

Bacteria can adhere to a surface within minutes of contamination. Biofilm begins organizing within hours. A mature, structured biofilm can establish within 24 to 72 hours. This is why intraoperative prevention and the immediate post-operative period are the critical windows, not the weeks that follow.

Is MRSP biofilm harder to treat than regular staph biofilm?

Yes, for two compounding reasons. MRSP is resistant to the beta-lactam antibiotics most commonly used in veterinary practice, leaving fewer antibiotic options. And the biofilm matrix further reduces antibiotic penetration of whichever agents are available. The combination means that MRSP biofilm infections have a narrower treatment window and a lower likelihood of resolution without implant removal compared to susceptible-strain biofilm infections.

Biofilm is the reason implant infections are so much harder to manage than surface wound infections. The biology changes the moment bacteria attach and begin producing their protective matrix. Prevention, through everything that reduces bacterial load at the operative site before closure, is the only reliable answer.

Resources

• Clinician's Brief. Bacterial Biofilms. cliniciansbrief.com
• The Veterinary Nurse. Biofilms and their significance in veterinary wound management. theveterinarynurse.com
• Companion Animal. Biofilms and surgical site infections. magonlinelibrary.com

IV catheter placement is one of the most frequently performed procedures in veterinary medicine. It is also one of the most frequently performed with insufficient aseptic technique.

Catheter-related bloodstream infection (CRBSI) is a well-documented complication in veterinary patients. It is almost entirely preventable with correct aseptic placement and maintenance technique.

What this covers: The asepsis standards for peripheral and central IV catheter placement in dogs and cats, based on AAHA 2018 Infection Control, Prevention and Biosecurity (ICPB) Guidelines, including site preparation, glove type selection, catheter handling, and dwell time management.Scope: Peripheral IV catheters, jugular catheters, and peripherally inserted central catheters (PICCs) in small animal patients. Both placement and maintenance asepsis are addressed.Key distinction: Peripheral short-term catheters and central/long-term catheters require different asepsis standards. Peripheral catheters: examination gloves. Central, jugular, and PICC catheters: sterile gloves. This distinction is clinically significant and frequently overlooked.

Key takeaways

• AAHA 2018 ICPB Guidelines are the current evidence base for veterinary IV catheter asepsis.
• Peripheral catheters: examination gloves and 0.5 to 2% CHG scrub diluted with saline.
• Central, jugular, and PICC catheters: sterile gloves and full aseptic prep.
• Do not palpate the insertion site after antiseptic prep without sterile gloves.
• Dwell time beyond 72 hours significantly elevates CRBSI risk; replace or reassess.
• Catheter site inspection at least once daily is required for all indwelling catheters.
• Disconnection and reconnection events are major contamination opportunities.

The asepsis risk from IV catheters

An IV catheter creates a direct pathway from the skin surface into the vascular system. Any bacteria present at the insertion site, on the catheter surface, or introduced through the catheter hub can travel directly into the bloodstream.

In veterinary critical care settings, CRBSI causes:

• Bacteremia and septicemia
• Extension of hospitalization
• Requirement for systemic antibiotic therapy
• Increased morbidity and mortality

Unlike SSI after surgery, CRBSI develops over the dwell time of the catheter. The risk accumulates with each hour of catheter presence, each disconnection and reconnection event, and each site care interaction performed without adequate technique.

AAHA 2018 ICPB Guidelines: the evidence framework

The American Animal Hospital Association 2018 Infection Control, Prevention and Biosecurity (ICPB) Guidelines provide the current veterinary standard for IV catheter asepsis.

Key AAHA 2018 ICPB requirements for peripheral IV catheterization:

• Remove hair from the insertion area
• Don examination gloves
• Use chlorhexidine scrub diluted with saline to 0.5 to 2% working concentration for skin preparation

Key requirements for central, jugular, and PICC catheters:

• Sterile gloves required for catheter placement
• Full aseptic preparation of the site (more extensive than peripheral prep)
• Sterile draping of the site

VETgirl's review of these guidelines notes: "For peripheral central venous catheters (PICC) or jugular central line catheters, following aseptic preparation I don sterile gloves for the cannulation procedure, as aseptic technique is very important with these longer dwelling catheters."

Site preparation: peripheral catheters

Hair removal

Clip or shave the insertion area. VETgirl recommends clipping around the entire circumference of the limb at the catheter site to prevent hair being dragged into the insertion site when taping.

Hair removal is not just aesthetic: hair carries surface bacteria that can contaminate the insertion site during catheter placement and securing.

Antiseptic application

Agent: CHG diluted with sterile 0.9% saline to a working concentration of 0.5 to 2%.

Zoetis guidance (via veterinary percutaneous IV catheter guide): "Following removal of hair and organic debris, chlorhexidine antiseptic scrub diluted with sterile 0.9% saline to a working concentration of 0.5 to 2.0% should be used to prepare the skin. Isopropyl alcohol (70% or greater) antiseptic can also be used in combination with the chlorhexidine scrub."

Technique: Circular motion from center of insertion site outward. At least two to three application passes.

Contact time: Allow the antiseptic to fully dry before insertion. Wet antiseptic is partially diluted at the point of contact and does not achieve its labeled kill claim.

Critical error: Do not palpate the insertion site after antiseptic preparation without sterile gloves. VETgirl specifically notes: "After the scrub has been performed, palpation of the insertion site should be avoided." Palpation to find the vein after prepping recontaminates the prepped site with finger flora.

Gloves

Examination (clean, non-sterile) gloves for peripheral catheter placement. Sterile gloves are not required for short-term peripheral catheters per AAHA 2018 ICPB.

Hand hygiene before gloving is required regardless of glove type.

Site preparation: central, jugular, and PICC catheters

Central venous catheters, jugular catheters, and PICCs have longer dwell times, larger caliber vessels, and more direct cardiac proximity than peripheral catheters. The consequence of contamination is more severe.

Full aseptic prep required:

• Larger clip area than for peripheral catheters
• Antiseptic preparation of broader site area
• Sterile gloves for placement
• Sterile draping of the site where possible

CHG concentration: 0.5 to 2% CHG-alcohol or CHG-saline combination. For cats, diluted CHG only (CHG-alcohol combinations may be appropriate; confirm CHG does not contact mucous membranes or ear canals).

Sterile glove technique: Once sterile gloves are donned, no contact with non-sterile surfaces before catheter placement. If the vein must be palpated after prep, use the sterile-gloved finger (which must not then contact non-sterile surfaces).

For comparing IV catheter asepsis to urinary catheter asepsis in dogs, including the parallel clean-to-sterile technique framework applied to urinary catheterization and how the two catheter types compare in asepsis requirement, that guide covers urinary catheter asepsis.

IV catheter placement and maintenance are medical asepsis procedures, not surgical asepsis. Understanding this distinction clarifies which standard governs each phase of care. For medical asepsis in veterinary clinics, including how the medical asepsis standard that governs IV catheter care differs from the surgical asepsis standard for OR procedures, that guide covers the medical asepsis framework.

Catheter handling and insertion

Catheter sterility

IV catheters are supplied sterile in individual packaging. Inspect each catheter before use:

• Packaging intact (no tears, moisture, or seal failure)
• Expiry date not exceeded
• Visual inspection of catheter: no kinking or visible contamination

Once the catheter is removed from its packaging, the catheter surface must not contact any non-sterile surface before vascular insertion.

Hub handling

The catheter hub is the most common contamination point during insertion and subsequent use. After placement:

• Apply a sterile cap or T-port immediately
• Do not allow the hub to rest against non-sterile surfaces
• Flush with sterile heparinized saline or sterile saline immediately to confirm patency

Catheter maintenance asepsis

Placement asepsis determines the starting bacterial load at the insertion site. Maintenance asepsis determines whether that load increases over the dwell period.

Site inspection

At minimum daily (more frequently in critical care patients): inspect the insertion site for:

• Redness, swelling, heat, or discharge at the site
• Catheter movement or partial displacement
• Occlusion or resistance to flushing

Any sign of local inflammation is an indication for catheter removal.

Dressing changes

• Change the catheter dressing when soiled, wet, or lifting at the edges
• At each dressing change: hand hygiene, examination gloves, fresh sterile primary contact material
• Inspect the insertion site before applying the new dressing

Disconnection and reconnection

Each disconnection and reconnection of the catheter hub is a contamination event. Protocols to minimize risk:

• Scrub the hub with 70% alcohol and allow to dry before any connection or disconnection
• Use needleless connectors (when available) to reduce disconnection frequency
• Minimize disconnections to clinically necessary events only

Dwell time

Peripheral IV catheter dwell time should not routinely exceed 72 hours in small animal veterinary patients. Beyond this threshold, CRBSI risk increases substantially.

In practice, replace or reassess catheters at 72 hours. If the catheter is still clinically necessary and the site appears healthy, reassessment by a clinician determines whether replacement or extension is appropriate. Do not extend dwell time by default without clinical assessment.

For common aseptic errors in catheter and clinical procedures, including the error categories most commonly identified in IV catheter placement and management, that guide covers the error taxonomy.

Feline-specific considerations

CHG for cats

CHG is appropriate for feline IV catheter site preparation at 0.5 to 2% concentration. Avoid contact with:

• Ear canals
• Mucous membranes
• Eyes

Cats that remove their IV catheters and groom the insertion site are at risk of CHG ingestion. Monitor all feline IV catheter sites; use protective bandaging and E-collars where cats persistently interfere.

Vein selection in cats

The cephalic and saphenous veins are standard peripheral sites in cats. Jugular catheters in cats require sterile placement technique as for dogs.

For IV catheter asepsis compared to urinary catheter asepsis in cats, including the specific sterile technique required for urinary catheterization in cats and how it compares to the IV catheter standard, that guide covers urinary catheter asepsis in cats.

IV catheter site preparation uses antiseptic agents (specifically CHG) within an aseptic technique framework. Understanding the difference between these two concepts clarifies why antisepsis of the insertion site is a component of, not a substitute for, the overall aseptic catheter placement procedure.

Asepsis vs. antisepsis in IV catheterization

For the distinction between asepsis and antisepsis, including how IV catheter site preparation uses antiseptic agents within an aseptic technique framework, and how these two concepts operate together in clinical practice, that guide covers the conceptual relationship.

Common catheter placement errors

Frequently asked questions

Should diluted CHG be mixed fresh each day?

Yes. Pre-diluted CHG solutions can become contaminated during storage, particularly if non-sterile water was used for dilution or if the dispensing container is not kept clean. Published CRBSI outbreaks in human medicine have been traced to contaminated pre-diluted CHG. Mix fresh diluted CHG daily using sterile 0.9% saline.

Is povidone-iodine acceptable as an alternative to CHG for catheter site prep?

Yes, where CHG is contraindicated (documented allergy, specific patient contraindication). PVI provides adequate antisepsis but has less residual activity than CHG and is more readily inactivated by blood or plasma at the insertion site. CHG is preferred by most current guidelines for peripheral vascular access site preparation.

Can IV catheter extension sets be reused between connections?

Extension sets should be changed per the manufacturer's recommendation or at catheter replacement, and whenever they are visibly contaminated or soiled. Reusing extension sets across multiple days without replacement increases the contamination burden at the catheter hub with each connection event.

IV catheter asepsis is medical asepsis applied to an invasive device. The principles are straightforward: prepare the site correctly, use the right gloves for the right catheter type, handle the hub as the sterile-critical point it is, monitor the site daily, and replace on schedule. The CRBSI that develops from inadequate IV catheter asepsis is as preventable as the SSI that develops from inadequate surgical asepsis. The only difference is that it happens more slowly and in a patient who is already compromised.

Resources

The following sources were used as reference and background for this article:

• VETgirl. Best Practices for Aseptic Skin Preparation for IV Catheter Placement. vetgirlontherun.com
• Zoetis US. How To Place A Percutaneous Intravenous Catheter in Canine and Feline Patients. zoetisus.com
• VETgirl. How to Place a Peripheral IV Catheter. vetgirlontherun.com
• Virginia Tech ARCD. SOP: Placing an Intravenous Catheter in Dogs and Cats. research.vt.edu
• AAHA. 2018 Infection Control, Prevention and Biosecurity Guidelines. aaha.org

Orthopedic implant surgery operates under a higher asepsis standard than any other category of veterinary surgical procedure. The reason is simple: a contaminated soft tissue wound can be debrided and treated. A contaminated implant usually cannot.

Once bacteria establish biofilm on a metal implant surface, systemic antibiotics cannot reliably penetrate it. Implant removal is frequently the only option for resolving established implant-associated infection.

What this covers: The specific asepsis requirements for orthopedic implant procedures in dogs and cats, why implants elevate SSI risk, the role of biofilm, MRSP considerations, and the components of an enhanced implant surgery asepsis protocol.Evidence base: TPLO SSI retrospective study (769 procedures; PMC10133455); DVM360 TPLO protocol improvement study; Veterinary Practice News MRSP and implant infection data; TPLO SSI rate review (PMC11946642).Key clinical fact: Bacteria commonly involved in veterinary SSI, particularly Staphylococcus species including MRSP, form biofilms on implant surfaces that prevent host immune response and antibiotic penetration. This makes prevention through asepsis more important than treatment after infection occurs.

Key takeaways

• Implant surface provides bacteria a substrate for biofilm, bypassing host immunity.
• MRSP-colonized dogs have a significantly elevated SSI risk for implant procedures.
• TPLO SSI rates of 7 to 28% have been reported; stricter asepsis reduces this substantially.
• Implant-associated infection usually requires implant removal for resolution.
• Double gloving is recommended for all implant procedures.
• OR traffic restriction is more critical for implant procedures than routine soft tissue surgery.
• Intraoperative lavage before closure addresses contamination accumulated during the procedure.

Why implants change the asepsis standard

The implant-associated infection mechanism

All surgical procedures carry SSI risk. Implant procedures carry additional risk because the implant itself creates a favorable environment for bacterial colonization.

How this works:

1. During surgery, bacteria are introduced into the wound through any asepsis lapse
2. Bacteria adhere to the implant surface (metal plates, screws, pins) within minutes to hours
3. They begin producing a polysaccharide extracellular matrix: biofilm
4. Within the biofilm, bacteria are physically protected from host neutrophils and macrophages
5. Antibiotic molecules cannot penetrate the biofilm at clinically achievable concentrations
6. The infection persists indefinitely unless the implant is removed

The minimum infective dose (number of bacteria required to establish infection) is dramatically lower in the presence of an implant than in soft tissue alone. This is why contamination events that might be manageable in soft tissue surgery can produce catastrophic outcomes in implant procedures.

Reported SSI rates for veterinary implant procedures

The highest-volume implant procedure in veterinary small animal surgery is the tibial plateau leveling osteotomy (TPLO) for cranial cruciate ligament repair.

Published SSI rates for TPLO:

• Overall SSI rate 0.8 to 14.3% in most cohort studies (PMC11946642)
• Some reports document rates of 19 to 28% including all complications (DVM360)
• The Finnish MRSP outbreak further elevated institutional SSI rates during that period

A retrospective study of 769 TPLO procedures (PMC10133455) confirmed that MDR bacteria isolation correlated with development of major infections requiring additional surgical treatment.

A DVM360 report documented that a specialty referral hospital reduced TPLO implant-associated infection rates by implementing a stricter asepsis protocol, demonstrating directly that asepsis changes outcomes.

The enhanced asepsis protocol for implant surgery

Standard surgical asepsis applies to all procedures. Implant surgery requires every component of that standard plus specific enhancements.

Pre-operative preparation enhancements

Surgical site preparation:

• Immediate pre-operative clipping only (no night-before clipping)
• Generous clip margins beyond anticipated incision
• Minimum three-pass antiseptic scrub sequence
• CHG-alcohol or PVI-alcohol combination for optimal immediate plus residual activity
• Full contact time observed; site fully dry before draping

Pre-operative MRSP risk assessment:

For high-risk patients (prior MRSP colonization, recent antimicrobial treatment, prior SSI, chronic skin disease), pre-operative screening and decolonization protocols should be considered. MRSP carrier status is a documented significant risk factor for SSI in orthopedic procedures.

Antimicrobial prophylaxis timing:

Cefazolin administered within 60 minutes of incision. Redosing every 90 to 120 minutes for procedures exceeding that interval. Discontinuation within 24 hours post-operatively per current stewardship guidance.

Note: Standard prophylaxis does not cover MRSP. Asepsis is the primary prevention for MRSP.

For MRSP prevention through proper asepsis, including why standard antibiotic prophylaxis does not reliably prevent MRSP SSI and what asepsis-based prevention looks like, that guide covers MRSP-specific prevention in detail.

Orthopedic surgery in dogs without implants still requires rigorous asepsis, but the specific enhancements that implant presence demands build on that foundation. For orthopedic surgery asepsis without implants, including the full perioperative asepsis protocol for canine orthopedic procedures across both implant and non-implant categories, that guide covers the broader orthopedic asepsis context.

Intraoperative enhancements

Double gloving:

Strongly recommended for all implant procedures. The inner glove provides a second barrier if the outer is perforated during bone work, wire handling, or saw use. Outer glove perforation during orthopedic procedures is common and frequently undetected without double gloving.

OR traffic restriction:

Implant procedures should have the most restrictive OR traffic policy of any procedure type. Each person in the OR contributes to airborne contamination load. Each door opening disrupts positive pressure. For implant procedures lasting several hours, cumulative contamination risk is significant.

Specific traffic standards:

• Only essential personnel present
• OR door remains closed throughout the procedure
• All required supplies confirmed in the OR before first incision
• No personnel re-entry during the procedure unless clinically essential

Implant handling:

• Implants remain in sterile packaging until immediate use
• Implants are transferred to the sterile field using sterile technique
• No implant contacts any non-sterile surface after removal from packaging
• If an implant is inadvertently contaminated, it is replaced; contaminated implants are never "cleaned" and returned to the field

Intraoperative lavage:

Surgical wound lavage before closure is standard for implant procedures. Copious sterile saline lavage removes loose debris, blood clots, and free bacteria that accumulated during the procedure.

For implant procedures specifically, antiseptic lavage before closure has been used to reduce residual bacterial contamination including biofilm-forming organisms. Non-antibiotic antiseptic lavage options, such as Simini Protect Lavage, reduce bacteria, biofilms, and resistant organisms at the wound before suturing. This is an intraoperative contamination control step that does not rely on systemic antibiotics and aligns with stewardship principles.

Post-operative considerations

E-collar or recovery suit: Essential. Licking the incision introduces oral bacteria including Staphylococcus species directly onto a wound with an underlying implant.

Activity restriction: Extended (typically 8 to 12 weeks for bone healing procedures). Physical activity stress can disrupt healing and may contribute to implant failure.

Wound monitoring protocol: More frequent assessment than for routine soft tissue surgery. Early SSI detection is critical because treatment options narrow rapidly once biofilm becomes established.

For TPLO-specific asepsis protocols, including the application of enhanced implant asepsis to the most common veterinary orthopedic implant procedure, that guide covers TPLO asepsis in procedural detail.

Environmental asepsis for implant procedures

The OR environment standard for implant procedures should meet or exceed the standard for general surgical procedures.

Specific environmental considerations:

• Dedicated orthopedic surgical suite where available
• OR surfaces cleaned and disinfected with terminal cleaning protocol before implant procedures
• HEPA filtration confirmed functional
• Positive pressure differential verified
• Minimum OR personnel count enforced throughout

For environmental control critical for implant surgery, including OR airflow, positive pressure standards, and traffic management specific to implant procedures, that guide covers the environmental requirements.

Instrument sterilization for implant procedures

All instruments used in implant procedures must be sterile. This includes:

• Surgical instruments (standard pack)
• Powered instruments (oscillating saw, drill): require sterilization of the handpiece or disposable sterile covers
• Implant insertion instruments (holding forceps, screwdrivers, guides)
• The implants themselves

Implant sterility:

Commercially supplied implants arrive sterile from the manufacturer with documented sterility assurance. They should not be re-sterilized unless specifically indicated by the manufacturer. Re-sterilization can alter implant surface characteristics (coating integrity, metallurgical properties) in ways that are not always apparent.

Pre-sterilized implants should be:

• Inspected for packaging integrity before use
• Confirmed within expiry date
• Opened onto the sterile field using sterile technique immediately before use

For implant instrument sterilization standards, including the full instrument reprocessing protocol applicable to orthopedic instruments, that guide covers the sterilization standards.

Frequently asked questions

What is the most common bacteria causing TPLO SSI?

Staphylococcus pseudintermedius, including methicillin-resistant strains (MRSP), is the most commonly isolated pathogen from TPLO SSIs. MDR isolates are increasingly prevalent. Standard cephalosporin prophylaxis does not cover MRSP. Asepsis preventing MRSP from entering the wound is the primary prevention strategy.

Is lavage with saline sufficient for implant procedures?

Copious saline lavage removes loose debris and bacteria and is the standard baseline for wound lavage. For high-risk procedures or patients with elevated MRSP risk, antiseptic lavage before closure provides additional bacterial reduction including against biofilm-forming organisms. The evidence for antiseptic lavage in veterinary implant surgery is accumulating, particularly given the limitations of antibiotic prophylaxis against MRSP.

How long after TPLO can SSI develop?

SSI after TPLO can develop weeks to months after the procedure, not just in the immediate post-operative period. Early SSI (within 30 days) typically reflects intraoperative contamination. Late SSI (30 days to 12 months) may reflect delayed biofilm maturation, incision licking, or hematogenous seeding. Extended post-operative monitoring is appropriate for all TPLO patients.

Should all TPLO patients be screened for MRSP?

Pre-operative MRSP screening for all TPLO candidates is increasingly supported by the literature, particularly given the elevated SSI rates for this procedure and the treatment difficulty when MRSP is involved. Practices with high TPLO volume should consider a formal pre-operative screening protocol in consultation with a veterinary infectious disease specialist or dermatologist.

Orthopedic implant surgery is the procedure where asepsis gaps have the highest consequences. The contamination that a healthy immune system manages in soft tissue surgery cannot be managed once biofilm forms on a metal implant. Prevention through rigorous asepsis across every perioperative step is not a higher standard of care. It is the minimum standard for implant surgery.

Resources

The following sources were used as reference and background for this article:

• NIH/PMC. Surgical site infection after 769 Tibial Plateau Leveling Osteotomies. pmc.ncbi.nlm.nih.gov
• DVM360. Improving Infection Rates After TPLO. dvm360.com
• Veterinary Practice News. Old and New Thoughts on Infection Control. veterinarypracticenews.com
• NIH/PMC. Comparison of SSI Rates in TPLO Using Perioperative vs. Peri- and Postoperative Antimicrobial Prophylaxis. ncbi.nlm.nih.gov

A break in surgical asepsis is a specific event: a moment when sterility in the operative field is compromised. It differs from an aseptic error in precision. An error is a departure from correct technique. A break is the consequence of an error that actually introduces contamination, or creates conditions where contamination is likely.

Understanding the distinction matters because the appropriate response differs. Some errors can be corrected before they produce a break. A break requires immediate remediation regardless of cause.

What this covers: The categories, mechanisms, and consequences of breaks in surgical asepsis in small animal veterinary practice, and the evidence-based framework for detection and response.Key principle: Breaks should be named immediately when observed. The OR culture that normalizes silence in response to a breach is the OR culture with the highest SSI rates.Evidence: Published data confirm that SSI risk increases 3.5-fold when there are lapses in adherence to aseptic principles, including non-obvious events such as OR movement and visitor traffic. Recurring minor breaks are more strongly associated with SSI than single large contamination events.Response framework: Identify, name, assess, remediate, document.

Key takeaways

• Breaks most commonly occur during gowning and gloving: This is the highest-risk phase for human-origin contamination in the operative setting.
• Many breaks go undetected without a designated field monitor: Self-monitoring in the OR is unreliable. External observation changes the rate of detection.
• The response to a break is as important as the break itself: Continuing without correction turns a manageable contamination event into a probable SSI.
• Breaks accumulate: The SSI literature consistently describes a pattern of multiple minor breaks, not single dramatic events, as the primary pathway to infection.
• Instrument breaks are the highest-consequence category: Direct introduction of bacteria into deep tissue bypasses host defense layers entirely.
• OR traffic is an underappreciated source of breaks: Each door opening and person movement increases airborne contamination counts measurably.

Break category 1: Gowning and gloving breaks

Mechanism

During donning of the sterile gown and gloves, the exterior sterile surfaces of both items are in close proximity to non-sterile surfaces including the scrub attire, skin, and surrounding environment.

How breaks occur

• Sterile towel contacts a non-sterile surface during hand drying, then contaminates the gown or gloves
• The gown exterior contacts the scrub attire or table edge during unfolding
• Ungloved skin touches the exterior glove surface during open gloving
• Hands are pushed through gown cuffs before gloving, eliminating closed gloving option
• Personnel touch their face, mask, or hair after gowning and before the procedure

Published incidence

AJVR (2025) observed 96 veterinary surgical procedures and found:

• Contact of sterile towel with non-sterile surfaces: 17.7% of cases
• Contact of gown with non-sterile surfaces: 17.7% of cases
• Touching sterile objects with bare hands: 12.5% of cases
• Overall protocol breach rate during scrubbing, gowning, and gloving: 46.3%

Response protocol

For the errors in aseptic technique that most commonly produce gowning and gloving breaks, including the full error taxonomy and incidence data across all error categories, that guide provides the upstream error context.

Break category 2: Sterile field contamination during setup

Mechanism

The instrument table and sterile field are established before the patient arrives in the OR. Breaks during setup contaminate instruments or surfaces before surgery begins.

How breaks occur

• Non-sterile outer packaging contacts the sterile field during instrument opening
• Circulating nurse touches the sterile field surface when setting items down
• Instruments fall during setup and are returned to the sterile field
• OR staff reach across the sterile field to retrieve items on the far side
• Sterile packs opened without confirming chemical indicator change

Prevention emphasis

Setup breaks are particularly consequential because contaminated instruments will contact the wound for the entire duration of the procedure. Unlike intraoperative breaks, where replacement is possible, setup contamination may go undetected.

The most effective prevention is a sterile field setup protocol where the circulating nurse opens all items toward the scrub technician rather than dropping items from above, and where chemical indicator status is verbalized before any pack is opened.

Break category 3: Intraoperative technique breaks

Mechanism

During the active procedure, the sterile field is maintained by the behavior of all team members. Breaks occur when this behavior departs from correct technique.

How breaks occur

Gowned personnel:

• Turning back to the sterile field (back of gown is non-sterile)
• Allowing hands to drop below waist level
• Leaning across the sterile field rather than stepping around it
• Glove perforation undetected and not replaced
• Touching drape edge with gloved instrument before wound contact

Non-gowned personnel:

• Reaching across the sterile field to hand items to the surgeon
• Standing too close to the sterile field, allowing clothing contact
• Circulating nurse touching the sterile surface while adding items

Equipment:

• Non-sterile cables or tubing contacting the sterile field
• Suction tubing not handled with sterile technique
• Overhead light handle touched by non-sterile hands

For the correct technique breaks deviate from, including the sterile field rules, personnel zones, and instrument handling standards that define correct intraoperative behavior, that guide provides the technical baseline.

Break category 4: OR environment breaks

Mechanism

OR environmental conditions can create contamination events independent of personnel technique, particularly through airborne routes.

How breaks occur

• OR door opened repeatedly during active surgery
• Excessive personnel in OR generating air currents and skin shedding
• HEPA filtration not functioning or not present
• Positive pressure ventilation failure allowing corridor air ingress
• Between-case cleaning not performed, leaving surface contamination from previous procedure
• Wet surfaces aerosolizing bacteria with foot traffic

The significance of door openings

Research in human surgical settings has quantified the contamination effect of OR door openings. Each opening introduces a corridor air pulse and disrupts positive-pressure differential. In procedures requiring strict contamination control, particularly orthopedic and implant surgeries, door traffic is actively counted and minimized as a matter of protocol.

Pre-procedure supply confirmation is the most effective single intervention: confirming all supplies are in the OR before the first incision eliminates the most common cause of door openings during surgery.

For OR standards that prevent breaks, including the physical infrastructure and access control standards that reduce environmental breaks, that guide covers the facility requirements in detail.

Break category 5: Patient preparation breaks

Mechanism

Preparation errors that contaminate the surgical site before it is draped create a break in the planned sterile environment before surgery even begins.

How breaks occur

• Antiseptic scrub performed in the wrong direction (inward rather than outward from incision center)
• Patient transported to OR on a contaminated surface after prep
• Patient positioned in the OR without confirming the prep site is protected
• Draping performed before antiseptic is fully dry
• Drape displaced during patient movement and repositioned rather than replaced

The repositioned drape error

Repositioning a displaced drape is one of the most common and underappreciated breaks in veterinary surgical practice. The underside of any drape that has moved across non-sterile tissue or equipment is contaminated. Placing it back does not restore sterility; it transfers contamination to the surgical field margin.

Correct response: place a new sterile drape over or instead of the displaced one.

Building a culture of break detection and correction

The literature is consistent on this point: technical knowledge of what constitutes a break is not the limiting factor in surgical asepsis performance. The limiting factor is whether breaks are named when they occur.

Structural elements of a correction culture

Designated field monitor:

One named team member, typically the scrub technician or an assigned observer, has explicit responsibility to watch the sterile field and name breaks as they occur. This role does not require seniority. It requires clarity of assignment.

Non-punitive naming:

The correction of a break must be separable from blame. A gloving mistake named and corrected immediately is far less consequential than one left uncorrected because the surgeon is too senior to correct. Training programs should explicitly address this dynamic.

Immediate response expectation:

Every named break generates an immediate response. The response options are limited: replace the contaminated item, reassess the sterile field, or halt and re-establish if the extent of contamination is unclear.

Documentation:

All breaks and responses should be logged in the surgical record. This serves quality improvement, SSI investigation, and medicolegal purposes.

For training that reduces asepsis breaks, including the elements of effective asepsis training programs that address team culture, break naming, and competency assessment, that guide covers the staff development component.

Effective training programs in this area must address the cultural barrier to naming breaks as explicitly as they address technical correct technique. Documented competency assessments with observed performance, rather than written tests alone, are the most reliable method of confirming real-world aseptic behavior.

For auditing to detect recurring breaks, including the audit methods that distinguish individual break events from systematic patterns requiring protocol revision, that guide provides the compliance monitoring framework.

Break response reference

Frequently asked questions

What is the difference between a break and an error in surgical asepsis?

An error is a departure from correct technique. A break is a specific contamination event that results from an error. Not all errors result in breaks. All breaks result from errors. The distinction matters for response: some errors can be corrected before they produce a break. Once a break has occurred, remediation of the contamination is required.

Is it possible to continue surgery after a significant break?

Yes, in most cases, after appropriate remediation. The surgeon must assess whether the contamination affected items or areas that can be replaced, covered, or cleaned. If the extent of contamination is unclear, halting to re-establish the sterile field is the conservative and appropriate choice.

How should the team respond when a senior surgeon makes a break?

With the same immediacy as when anyone else does. Seniority does not reduce the contamination consequence of a break. Clinics that build an explicit expectation of named, non-judgmental break correction regardless of personnel rank consistently maintain better aseptic outcomes than those with hierarchical correction norms.

Breaks in surgical asepsis are a normal feature of surgical practice. They are not evidence of failure; they are evidence that humans are performing complex tasks in a demanding environment. What determines outcomes is not whether breaks occur but whether they are seen, named, and corrected before they translate into patient harm.

Resources

The following sources were used as reference and background for this article:

• AVMA Journals. Aseptic protocol breaches are common among veterinary students. AJVR, 2025. avmajournals.avma.org
• PubMed. Aseptic protocol breaches during SGG in veterinary students. pubmed.ncbi.nlm.nih.gov
• Veterian Key. Principles of Surgical Asepsis. veteriankey.com
• WSAVA 2014. Maintaining a Sterile Operating Environment. vin.com