Urinary catheterization in dogs is a common veterinary procedure used to relieve urinary obstruction or collect sterile urine samples. However, improper technique can introduce bacteria into the urinary tract, leading to infections. Understanding asepsis for urinary catheterization in dogs is crucial to protect your pet's health and ensure the procedure's success.

This article provides a clear guide on aseptic techniques during urinary catheterization in dogs. You will learn why asepsis matters, how to prepare equipment and the patient, and best practices to minimize infection risks during catheter insertion and maintenance.

What is asepsis in urinary catheterization for dogs?

Asepsis means preventing contamination by harmful microorganisms during medical procedures. In urinary catheterization, asepsis involves techniques to keep the catheter and urinary tract free from bacteria. This reduces the chance of urinary tract infections (UTIs), which can cause pain and serious complications in dogs.

Maintaining asepsis requires careful preparation, sterile equipment, and clean handling throughout the catheterization process. It is a critical part of veterinary care for dogs needing catheter placement.

• Definition of asepsis: Asepsis is the practice of preventing infection by eliminating bacteria and other microbes during catheterization.
• Importance in catheterization: Proper asepsis lowers the risk of introducing bacteria into the urinary tract, preventing UTIs.
• Common infections prevented: Asepsis helps avoid cystitis, pyelonephritis, and other urinary infections in dogs.
• Role in veterinary practice: Aseptic technique is a standard of care to protect animal health during invasive procedures.

Understanding asepsis sets the foundation for safe urinary catheterization and improves outcomes for your dog.

How do you prepare for aseptic urinary catheterization in dogs?

Preparation is key to maintaining asepsis during catheterization. This includes gathering sterile equipment, cleaning the dog's genital area, and ensuring a clean environment. Proper preparation reduces contamination risks before catheter insertion.

Veterinarians and veterinary technicians follow strict protocols to prepare both the patient and the workspace for aseptic catheterization.

• Equipment sterilization: Use sterile catheters, gloves, lubricant, and drapes to prevent bacterial contamination.
• Patient cleaning: Thoroughly clean the dog's genital area with antiseptic solutions to reduce skin bacteria.
• Environment control: Perform the procedure in a clean, controlled area to limit airborne contaminants.
• Personnel hygiene: Wear sterile gloves and wash hands properly before handling the catheter and patient.

Proper preparation helps create a sterile field and minimizes infection risks during catheter placement.

What are the steps to maintain asepsis during catheter insertion in dogs?

Maintaining asepsis during catheter insertion involves careful technique and attention to detail. Each step must avoid introducing bacteria into the urinary tract. This requires sterile handling of the catheter and minimizing contact with non-sterile surfaces.

Following a step-by-step aseptic protocol ensures safe catheter placement and reduces infection chances.

• Use sterile gloves: Always wear sterile gloves to handle the catheter and avoid touching non-sterile surfaces.
• Lubricate catheter with sterile lubricant: This reduces friction and prevents trauma while maintaining sterility.
• Avoid catheter contamination: Do not let the catheter touch the dog's fur or skin outside the cleaned area.
• Insert catheter gently: Carefully advance the catheter into the urethra without forcing to prevent tissue damage and infection.

Adhering to these steps protects the urinary tract from contamination and supports successful catheterization.

How should you care for the catheter to maintain asepsis after placement?

After catheter placement, ongoing care is essential to maintain asepsis and prevent infections. This includes regular cleaning, monitoring for signs of infection, and proper handling during urine collection or catheter changes.

Good catheter care helps keep the urinary tract sterile and reduces complications.

• Secure catheter placement: Fix the catheter to prevent movement that can introduce bacteria or cause injury.
• Keep insertion site clean: Regularly clean the area around the catheter with antiseptic solutions to prevent bacterial growth.
• Use closed collection systems: Closed urine collection bags reduce exposure to environmental bacteria.
• Monitor for infection signs: Watch for redness, swelling, discharge, or discomfort indicating possible infection.

Proper catheter care after insertion is vital for maintaining asepsis and your dog's comfort.

What are common complications from poor asepsis in dog catheterization?

Poor aseptic technique during urinary catheterization can lead to several complications. The most common is urinary tract infection, which can cause pain, fever, and more serious kidney infections. Other complications include urethral trauma and catheter blockage.

Recognizing these risks highlights why asepsis is critical in catheter procedures.

• Urinary tract infection: Bacteria introduced during catheterization can cause bladder and kidney infections.
• Urethral injury: Improper technique or contamination can cause tissue damage and inflammation.
• Catheter blockage: Infection or debris can block urine flow, requiring catheter replacement.
• Systemic infection risk: Severe infections can spread, leading to sepsis if untreated.

Preventing these complications depends largely on strict aseptic technique throughout catheter use.

How can pet owners support asepsis during and after catheterization?

Pet owners play an important role in supporting asepsis during and after urinary catheterization. Following veterinary instructions carefully and maintaining hygiene at home helps prevent infections and complications.

Understanding your role improves your dog's recovery and comfort.

• Follow veterinary care instructions: Adhere to all cleaning and catheter care guidelines provided by your vet.
• Maintain hygiene: Wash hands before touching the catheter or urinary area to avoid contamination.
• Monitor your dog: Watch for signs of discomfort, swelling, or discharge and report concerns promptly.
• Keep follow-up appointments: Regular veterinary checks ensure the catheter remains clean and functioning properly.

Active owner involvement supports asepsis and promotes your dog's health during catheterization.

What are the best antiseptic agents for urinary catheterization in dogs?

Choosing the right antiseptic agents is important for effective asepsis in urinary catheterization. These agents clean the skin and reduce bacteria without causing irritation. Veterinary professionals select antiseptics based on safety and efficacy.

Using appropriate antiseptics helps maintain a sterile field and protects the urinary tract.

• Chlorhexidine gluconate: A broad-spectrum antiseptic effective against bacteria and safe for canine skin.
• Povidone-iodine: Commonly used antiseptic that kills bacteria but may cause mild skin irritation in some dogs.
• Alcohol-based solutions: Used for rapid disinfection but can be drying and should be used carefully.
• Sterile saline: Used for rinsing after antiseptic application to remove residues and debris.

Proper antiseptic choice and application improve asepsis and reduce infection risk during catheterization.

Conclusion

Asepsis for urinary catheterization in dogs is essential to prevent infections and ensure safe catheter use. Proper preparation, sterile technique during insertion, and careful catheter care reduce the risk of urinary tract infections and other complications.

Pet owners and veterinary professionals must work together to maintain asepsis throughout the catheterization process. Understanding and following aseptic principles protect your dog's health and promote a smooth recovery.

FAQs

How often should the catheter be changed to maintain asepsis?

Catheter change frequency depends on the dog's condition and catheter type but typically occurs every 3 to 7 days to reduce infection risk and maintain sterility.

Can I clean the catheter insertion site at home?

Yes, you can clean the site using sterile wipes or antiseptic solutions recommended by your vet, ensuring your hands are clean before touching the area.

What signs indicate a urinary tract infection in my dog?

Signs include frequent urination, straining, blood in urine, foul odor, licking the genital area, and discomfort. Contact your vet if these occur.

Is it safe to use over-the-counter antiseptics for catheter care?

Only use antiseptics approved or recommended by your veterinarian, as some human products can irritate or harm your dog’s skin.

What should I do if the catheter becomes blocked?

If blockage occurs, do not attempt to fix it yourself. Contact your veterinarian immediately for assessment and safe catheter management.

Abscess drainage is classified as a dirty-infected wound procedure. It involves the deliberate opening of a pre-existing infection, which creates contamination of the drainage site, instruments, gloves, and surrounding tissues at the moment of incision.

The asepsis goal during abscess drainage is not sterility, which is unachievable in this context. It is contamination control: preventing further spread of the infection to adjacent tissues, other patients, and clinical staff.

What this covers: The asepsis principles and practical protocol for abscess drainage in dogs and cats, including patient preparation, incision site selection, lavage, contamination control, wound management post-drainage, and the specific asepsis requirements for different abscess types.Wound class: Dirty-infected (Class IV). Pre-existing infection is present. SSI rates for dirty-infected procedures range from 18 to 27%+ in the absence of appropriate management.Key principle: Because the procedure opens an infected cavity, the emphasis shifts from preventing contamination of the wound (as in clean surgery) to controlling the spread of contamination from the wound to the patient, the staff, and the clinical environment.

Key takeaways

• Abscess drainage is Class IV (dirty-infected); the wound already contains infection.
• The asepsis goal is contamination control, not wound sterility.
• Wide clip margins prevent hair contamination of the drainage site and surrounding area.
• Lavage after drainage is the most important asepsis step for contamination control.
• Instruments must be treated as contaminated after the abscess opens; do not return to the sterile field.
• Staff PPE (gown, gloves, eye protection) is essential; abscess contents aerosolize during incision.
• Environmental disinfection of the procedure area post-drainage must be thorough.

Pre-procedure preparation

Patient assessment and sedation

Abscess drainage requires adequate analgesia and, in many cases, sedation or general anesthesia. Pain and patient movement during incision compromise contamination control.

Assess for:

• Extent and depth of the abscess (palpation, imaging where indicated)
• Signs of systemic involvement (fever, lethargy, regional lymphadenopathy)
• Identifying the most dependent site for drainage

Bite wound abscesses in cats: Cat bites produce small, deep puncture wounds that frequently develop into deep abscesses. Careful palpation and imaging can reveal the full extent before incision.

Perianal abscesses: Perianal fistulae and anal sac abscesses require specific preparation to minimize fecal contamination during drainage.

Clipping

Clip a generous area around the abscess, extending well beyond the anticipated incision site. University of Minnesota Clinical Skills guidance notes: "Be sure to extend clip below the planned draining stab wound to prevent hair from contaminating the drainage hole, and to keep the area easier to clean of drainage material."

The clip area also needs to extend below the drainage site in the animal's normal standing position, because gravity-assisted drainage will track downward and hair in that path will become contaminated and trap purulent material against the skin.

Skin antisepsis

Apply standard antiseptic scrub to the clipped area around the abscess, using centrifugal technique from the intended drainage site outward. Chlorhexidine-alcohol combination is appropriate.

Important: The abscess wall itself cannot be made sterile by skin antisepsis. The purpose of antisepsis here is to reduce surface contamination adjacent to the drainage site, limiting additional organisms from the skin surface entering the wound.

Staff preparation and PPE for abscess drainage

Abscess drainage requires more protective PPE than clean surgical procedures because:

• The procedure opens a pre-existing infected, often under-pressure cavity
• Purulent material may express at force when the abscess is incised, creating aerosol
• Staff hands, face, and clothing may be exposed to infectious material

Required PPE:

• Gloves: Required throughout; change to a fresh pair after the abscess opens if further sterile field work is needed
• Gown or apron: Protects clothing from purulent material splatter
• Eye protection/face shield: Essential; abscess contents frequently aerosolize at incision
• Mask: Reduces inhalation exposure to aerosolized infectious material

Drainage technique and asepsis

Incision site selection

Select the most dependent site in the abscess when the animal is in normal standing position. This allows passive gravity drainage after the incision is made and minimizes abscess pocket residue.

For bite wound abscesses in cats: locate opposing tooth marks (entry and exit wounds). The abscess often tracks between these points.

Incision

Make a stab incision of sufficient size to allow drainage of thick pus. Too small an incision risks the pocket resealing before the contents fully drain.

After the abscess opens:

• Any instrument that entered the abscess is now contaminated
• Gloves contacting the abscess contents are contaminated
• Do not return contaminated instruments to any sterile field

Lavage after drainage

Lavage is the most important asepsis step after the abscess opens.

Purpose: Mechanically remove purulent material, bacteria, and debris from the abscess pocket and surrounding tissue.

Irrigation solution: Sterile saline. Volume: sufficient to produce clear runoff from the cavity. For large abscesses, 100 to 500+ mL may be required.

Dilute antiseptic lavage: Dilute chlorhexidine (0.05%) or dilute PVI (0.1 to 1%) may be used for the initial lavage of an established abscess. Both reduce bacterial load beyond what saline alone achieves. Do not use concentrated antiseptic solutions within the abscess cavity as they damage granulation tissue.

University of Minnesota guidance: "Flush the abscessed area to remove pus and any gross contamination. Flush solution should be tissue-friendly, aid in removal of bacteria, and ideally isotonic to preserve normal function of cells to promote healing."

Culture

Where clinically appropriate, submit purulent material for aerobic and anaerobic culture and sensitivity testing before lavage. This provides the most reliable identification of causative organisms and guides antimicrobial selection.

In cats with bite wound abscesses, culture is often not performed for straightforward cases where Pasteurella and anaerobes are the expected organisms. For recurrent abscesses, non-responsive cases, or immunosuppressed patients, culture is indicated.

For asepsis principles during wound management, including how abscess drainage fits within the broader wound management asepsis framework and the clean technique standards for ongoing wound care after drainage, that guide covers wound management asepsis in detail.

The intraoperative technique framework for abscess drainage, including sterile field management before the abscess opens and the instrument handling and field abandonment protocol once purulent material is encountered, follows the aseptic technique framework adapted to the dirty-infected context. For core aseptic technique applied during drainage, including the sterile field principles and instrument handling standards that apply before and after the abscess opens, that guide covers the technique framework.

Post-drainage wound management

Open or closed management

Open drainage: Leave the incision open to allow continued drainage. This is appropriate when:

• The abscess is extensive and a single drainage is unlikely to resolve it
• Daily lavage through the open stoma is planned
• Risk of premature closure causing re-accumulation is high

Closed drainage: Primary closure with a drain. Used when:

• The abscess is fully drained and lavaged
• The tissue bed is viable
• Suction or passive drainage can be maintained through a Penrose or closed-suction drain

Closed without drainage: Rarely appropriate for established abscesses. Reserved for small, clean-appearing cavities where the surgeon is confident complete drainage was achieved.

Ongoing wound care

For open-managed abscesses, continued clean technique applies at each dressing change:

• Hand hygiene before any wound contact
• Sterile primary dressing or sterile lavage
• Clean outer bandaging layers

Antimicrobial therapy

Abscess drainage (Class IV wound) warrants antimicrobial therapy, not prophylaxis. Selection should be guided by culture results where available.

For cat bite abscesses without culture: Pasteurella multocida and anaerobic organisms are the primary targets. Amoxicillin-clavulanate provides appropriate coverage for most straightforward cat bite abscesses.

For non-responsive or recurrent cases: culture-guided selection is essential.

Environmental decontamination after abscess drainage

The procedure area requires thorough disinfection after abscess drainage because the environment may be contaminated with purulent material, including organisms that could persist on surfaces and transmit to subsequent patients.

Required steps after abscess drainage:

• Table surface: full disinfection with intermediate-level agent; observe contact time
• Any equipment contacted during the procedure: disinfect per material manufacturer guidelines
• Floor below the drainage site: mop with appropriate disinfectant
• Staff gown and gloves: dispose; do not reuse
• Hand hygiene for all staff involved: thorough wash with soap and water

If significant splatter occurred, extend decontamination to walls, adjacent equipment, and any other surfaces with visible contamination.

For errors to avoid during abscess drainage, including the specific aseptic error categories that are most consequential during dirty-infected wound procedures, that guide covers error prevention.

Specific abscess types: additional considerations

Cat bite abscesses

The most common abscess type in small animal veterinary practice. Cats introduced to multi-cat households or free-roaming outdoors are at highest risk.

Asepsis considerations:

• Explore carefully: bite wound tracts can be deep and tortuous
• Multiple drainage points may be needed if the tract extends far from the visible wound
• Elizabethan collar post-drainage is essential in cats; they will groom the drainage site aggressively

Anal sac abscesses

Close proximity to the anus creates ongoing contamination risk from fecal flora.

Asepsis considerations:

• Clip widely; include adequate area caudal to the abscess for drainage clearance
• Position patient to maximize access while minimizing fecal contamination spread
• Copious lavage essential
• Open management typically preferred to allow continued drainage with daily wound flushing

Perianal fistulae (anal furunculosis)

More complex than simple anal sac abscess; involves extensive sinus tracts. Often managed with a combination of immunosuppressive therapy and surgical debridement rather than simple drainage alone. Aseptic technique for any surgical intervention follows the dirty-infected protocol.

For skin antisepsis before drainage procedures, including the skin prep technique and agent selection applicable when antisepsis of the peri-abscess skin is performed before drainage, that guide covers the antisepsis component.

Frequently asked questions

Do abscesses in cats require general anesthesia for drainage?

In most cases, yes. General anesthesia or deep sedation is required for safe, thorough abscess drainage in cats. Inadequate analgesia results in patient movement that compromises contamination control and prevents adequate exploration and lavage. Topical analgesia alone is insufficient for established abscesses.

Should abscess drainage be performed in the OR or a procedure room?

A clean procedure room with appropriate disinfection before and after is sufficient for most abscess drainage procedures. The OR is not required unless the abscess is extensive and requires general anesthesia with the full surgical infrastructure. After the procedure, the area must receive the same enhanced disinfection protocol regardless of which room was used.

Can antibiotics alone resolve an abscess without drainage?

Rarely. The physical presence of purulent material in an abscess cavity provides a protected environment for bacteria that antibiotics cannot adequately penetrate. Drainage removes the bacterial reservoir. Antibiotics address residual infection after drainage. The combination is more effective than either alone.

Abscess drainage is the procedure where the contamination is already there, and the asepsis goal is to stop it spreading further. Generous clip margins, copious lavage after drainage, full PPE for all personnel involved, and rigorous environmental decontamination after the procedure are the components that distinguish controlled abscess management from a procedure that contaminates the patient, the staff, and the clinical environment.

Resources

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

• University of Minnesota Clinical Skills Compendium. Abscess Management in Cat/Dog. open.lib.umn.edu
• Merck Veterinary Manual. Management of Specific Wounds in Small Animals. merckvetmanual.com
• Merck Veterinary Manual. Initial Wound Management in Small Animals. merckvetmanual.com

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

Soft tissue surgery in dogs encompasses a wide range of procedures, from elective spay and neuter to emergency GI resection. The asepsis standard differs substantially across this range, and applying the wrong standard in either direction, too strict where it is unnecessary or too lax where it is essential, produces inefficiency or infection respectively.

What this covers: The perioperative asepsis protocol for soft tissue surgery in dogs, including wound classification, procedure-specific SSI risk factors, patient preparation, intraoperative standards, and tract-specific considerations for GI, urinary, and respiratory surgery.Evidence base: PMC6802975 SSI incidence study in dogs undergoing soft tissue surgery; ATDove SSI risk factor review; The Veterinary Nurse SSI preparation and prevention; wound classification framework.SSI rate context: Clean soft tissue procedures (elective, no tract entry): 2 to 5% in veterinary literature. Clean-contaminated (controlled tract entry): 5 to 10%. Contaminated and dirty: 4 to 18% depending on degree and source of contamination.

Key takeaways

• Wound class determines the asepsis standard and SSI risk baseline for each procedure.
• Procedure duration over 60 minutes is a documented independent SSI risk factor in dogs.
• Tract entry (GI, urinary, respiratory) elevates wound class and requires protocol modification.
• Patient risk factors (endocrinopathy, obesity, ASA score) compound procedure SSI risk.
• Skin antisepsis, instrument sterilization, and sterile technique apply to all soft tissue cases.
• Antibiotic prophylaxis is indicated for clean-contaminated and above; not routine for clean.
• Lavage before closure is standard for contaminated and dirty procedures.

Wound classification for canine soft tissue surgery

The CDC surgical wound classification system provides the framework for matching asepsis standard to procedure type:

For all classes, the full standard surgical asepsis protocol applies. Class II and above require additional considerations for lavage, potentially antimicrobial prophylaxis, and wound management decisions.

Patient risk factors for soft tissue SSI in dogs

Procedure class is not the only determinant of SSI risk. Published veterinary literature documents the following patient-level risk factors:

Endocrinopathies:

Hyperadrenocorticism (Cushing's disease) is the most strongly documented patient risk factor for SSI in dogs. Dogs with Cushing's disease have substantially higher SSI rates than dogs without endocrinopathy undergoing the same procedure. Hypothyroidism and diabetes mellitus also elevate risk.

Obesity:

Obese dogs have thicker subcutaneous tissue layers, reduced subcutaneous blood supply, and potentially reduced immune competence. These factors elevate SSI risk and complicate wound closure.

ASA score:

Higher ASA physical status classification (indicating more severe systemic disease) is an independent predictor of SSI in the veterinary literature, consistent with human surgical data.

Procedure duration:

Surgery duration over 60 minutes is a documented independent SSI risk factor in dogs (PMC6802975). The relationship holds when controlling for procedure type and patient factors. Efficient technique that minimizes operative time is itself an infection prevention measure.

Active infection at another site:

Presence of concurrent infection (urinary tract infection, skin infection, dental disease) elevates SSI risk through bacteremia risk and potential immune system distraction.

Pre-operative preparation for canine soft tissue surgery

Patient preparation

Clipping:

Clip margins should extend at least 5 to 10 cm beyond the anticipated incision. For abdominal procedures, clip from mid-sternum to pubis and lateral extension to include both flanks.

Clip immediately before surgery. Do not use razors.

Skin antisepsis:

Standard three-pass centrifugal scrub sequence. CHG-alcohol combination preferred for most body sites due to residual activity. PVI preferred for ophthalmic, ear, and some oral procedures.

For abdominal surgery in female dogs: include the vulvar region in the prep area and apply a sterile drape or cover to minimize contamination from normal vulvar flora.

Pre-operative fasting:

Standard pre-anaesthetic fasting (minimum 8 to 12 hours for solid food) reduces GI content volume and aspiration risk, but also reduces contamination load if GI tract is entered or perforated.

Antibiotic prophylaxis

Clean procedures (Class I):

Antimicrobial prophylaxis is not routinely indicated for clean elective soft tissue surgery in healthy dogs. Standard aseptic technique applied correctly produces SSI rates within the 2 to 5% expected range without prophylaxis.

Clean-contaminated procedures (Class II):

Prophylaxis is indicated. Selection based on likely pathogens for the specific tract entered:

• GI surgery: cover gram-negative bacteria and anaerobes (e.g., ampicillin-sulbactam or cefoxitin)
• Urinary tract: cover gram-negative uropathogens (e.g., enrofloxacin or ampicillin)
• Respiratory: cover typical respiratory pathogens

Contaminated and dirty (Class III and IV):

Therapeutic antimicrobial therapy, not prophylaxis. Culture and sensitivity where possible.

Intraoperative asepsis for canine soft tissue surgery

Sterile field management

Standard sterile field principles apply: sterile instruments, sterile gown and gloves, correct draping, sterile technique throughout.

Abdominal procedures:

• Impervious draping to isolate the abdominal incision from the flanks and thorax
• Saline-moistened laparotomy sponges used to pack off adjacent organs during GI work
• Any instrument or sponge that contacts the bowel lumen should be considered contaminated and removed from the sterile field

Soft tissue exposure:

During deep tissue dissection, retractors should be wetted to reduce tissue trauma. Minimize tissue handling. Atraumatic technique reduces devitalized tissue at the wound site, reducing the substrate available for bacterial colonization.

GI tract entry

When the GI tract is entered under controlled conditions (enterotomy, intestinal resection and anastomosis):

• Isolate the segment being operated on with intestinal forceps or umbilical tape to minimize luminal content spillage
• Double-glove change after GI closure and before abdominal closure
• Copious lavage before abdominal closure
• Instrument change: instruments that contacted the GI lumen are removed from the sterile field

For core aseptic technique, including the sterile field maintenance and instrument handling standards that apply throughout the intraoperative phase for all procedure types, that guide covers the intraoperative technique framework.

The canine skin antisepsis protocol is a critical foundation for all soft tissue cases. For skin antisepsis preparation for dogs, including the complete centrifugal scrub technique, agent selection, contact time requirements, and common preparation errors specific to canine patients, that guide covers the step-by-step preparation protocol.

Lavage before closure

Wound lavage before closure is standard for all Class II and above procedures and should be considered for extended Class I procedures.

Purpose: Remove debris, blood clots, and bacteria that accumulated during the procedure.

Volume: 300 to 500 mL minimum for abdominal procedures; larger volumes for grossly contaminated cases.

Agent: Sterile saline is the standard baseline. For contaminated or dirty cases, antiseptic lavage may be used before closure.

Dead space management

Eliminating dead space at closure reduces the blood and fluid accumulation that supports bacterial growth. Techniques:

• Obliterating subcutaneous dead space with walking sutures where anatomically appropriate
• Closed-suction drains for large dead space that cannot be eliminated
• Omentum mobilization to fill dead space in abdominal procedures when indicated

Tract-specific asepsis considerations

Pyometra surgery

Pyometra presents as a Class IV (dirty) procedure with pre-existing uterine infection. Additional considerations:

• Culture the uterine exudate intraoperatively for culture and sensitivity
• Minimize spillage during ovariohysterectomy
• Copious lavage if spillage occurs
• Therapeutic antibiotics, not prophylaxis
• Consider active infection control precautions for the post-operative patient

Cystotomy

Class II (clean-contaminated) procedure. Urine culture before surgery when possible to guide antimicrobial selection. Double-glove change after bladder closure. Lavage before abdominal closure.

For asepsis during soft tissue surgery in cats for comparison, including the feline-specific considerations that differ from the canine soft tissue asepsis protocol, that guide covers the cat-specific approach.

Frequently asked questions

Does wound class change if an unplanned event occurs during surgery?

Yes. An unexpected GI perforation during an elective procedure reclassifies the wound from Class I to Class III. This changes the intraoperative lavage requirement, post-operative monitoring intensity, and possibly the antimicrobial plan. The surgeon should acknowledge the reclassification and adjust the protocol accordingly.

Is skin closure method relevant to SSI risk in soft tissue surgery?

Yes. Subcutaneous closure technique affects dead space and wound tension. Excessive tension at the skin closure impairs blood supply to the wound edge, reducing local immune competence. Some evidence suggests that minimizing subcutaneous suture material reduces wound reaction and SSI risk, though specific data in veterinary soft tissue surgery is limited.

How should contaminated wound cases be handled in terms of OR scheduling?

Contaminated and dirty-infected cases should be scheduled last in the surgical day where possible, to allow full terminal cleaning of the OR after the procedure. If this is not possible, thorough terminal cleaning (not just between-case cleaning) should follow a contaminated or dirty procedure before the next sterile case.

For surgical asepsis standards for all canine surgery, including the five-domain surgical asepsis framework that underlies the procedure-specific applications covered in this guide, that guide covers the full standard.

Applying the correct asepsis standard to the correct procedure class requires not just knowing the protocol but consistently executing it without the errors that most commonly compromise soft tissue surgical asepsis in practice.

For common errors in soft tissue asepsis, including the most common aseptic error categories documented in small animal surgical practice and how to prevent them, that guide covers the error taxonomy that applies throughout soft tissue surgery.

Soft tissue surgery in dogs spans a wide range of contamination risk, and the asepsis protocol must be matched to that range. The same core principles apply to every case: sterile instruments, correct technique, appropriate skin prep, and matched antimicrobial strategy. What changes is the intensity, duration, and lavage requirement based on wound class and patient risk. Matching the protocol to the procedure is as important as applying it correctly.

Resources

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

• NIH/PMC. Incidence of SSI in dogs undergoing soft tissue surgery: risk factors and economic impact. pmc.ncbi.nlm.nih.gov
• ATDove. Surgical Site Infection. atdove.org
• The Veterinary Nurse. Surgical site infections: preparation, technique and perioperative prevention. theveterinarynurse.com
• WSAVA 2014. Maintaining a Sterile Operating Environment. vin.com

Surgical site infection remains one of the most consequential complications in veterinary surgery. It extends recovery, increases cost, compromises implants, and in severe cases is life-threatening.

Asepsis is the discipline that prevents it. Establishing and maintaining a contamination-free surgical field from patient prep through wound closure is the foundation of safe small animal surgery.

What this covers: The core principles, protocols, and standards of surgical asepsis in small animal veterinary practice.Scope: Applies to all survival surgical procedures in dogs and cats, from routine spay/neuter to complex orthopedic reconstruction.Key distinction: Surgical asepsis aims for sterility within the operative field. Medical asepsis, applied outside the OR, aims to reduce microbial load rather than eliminate it.Clinical relevance: Halstead's principles of atraumatic surgery, first articulated in the 1880s, remain the framework. Their application in modern small animal surgery includes multimodal infection control across every phase of the perioperative period.

Key takeaways

• Surgical asepsis encompasses every phase of the perioperative period: Not just intraoperative sterility, but patient preparation, instrument sterilization, staff protocols, and OR environment.
• The sterile field is defined by physical and procedural boundaries: Anything below waist level, anything non-sterile that enters the field, and any breach of gloving or gowning technique compromises it.
• Skin preparation is a critical but imperfect step: Antiseptic scrubbing reduces surface bacteria dramatically but does not sterilize skin. Residual bacteria from hair follicles and sebaceous glands remain.
• Instrument sterilization failure is the most consequential single-point error: Contaminated instruments render all other aseptic measures irrelevant.
• Aseptic breaks are common and frequently unrecognized: Studies in veterinary surgical training contexts document high rates of undetected technique violations. Formal monitoring matters.
• Intraoperative wound lavage is an additional layer of contamination control: At the conclusion of surgery, lavage with an appropriate antiseptic agent addresses residual bacterial load before wound closure.

Defining surgical asepsis

Surgical asepsis is formally defined as the total elimination of microorganisms and their spores from materials and areas that contact the surgical wound.

This is distinct from antisepsis, which involves applying chemical agents to living tissue to reduce (not eliminate) microbial load.

The goal of surgical asepsis is sterility within the surgical field. In practice, true sterility cannot be fully achieved in a live patient, but the cumulative effect of rigorous aseptic protocols reduces contamination to levels that the immune system can contain without clinical infection.

Asepsis is not a single step. It is the sum of every contamination-prevention decision made from the moment the surgical site is identified to the moment the final skin suture is placed.

For the conceptual distinction between how surgical asepsis differs from medical asepsis, and why the sterility standard in the OR does not apply to examination rooms, treatment areas, and other clinical spaces, that guide covers the boundary between the two disciplines clearly.

The five domains of surgical asepsis

Surgical asepsis operates across five interdependent domains. A lapse in any one domain can negate the efforts of the others.

1. Patient preparation

Hair removal:

Clipping, rather than shaving, is the current standard. Razors create micro-abrasions that increase bacterial colonization at the surgical site. Clipping should be performed immediately before surgery, not the night before, to minimize recolonization time.

The clip area should extend well beyond the anticipated incision to provide margin for unexpected surgical extension.

Skin antisepsis:

A minimum of two antiseptic applications is standard, typically alternating antiseptic and sterile saline or alcohol. The most commonly used agents are:

Scrubbing should proceed in a circular pattern from the incision center outward, never reversing direction. This prevents recontamination of the prepared site from the periphery.

Patient positioning and draping:

Sterile drapes isolate the surgical site from the surrounding patient and table. All surfaces below the drape level are considered non-sterile. Only the draped field is sterile.

Drapes must be placed without contaminating the draped area. Once placed, drapes should not be repositioned.

2. Instrument sterilization

All instruments contacting the surgical wound must be sterile.

The autoclave (steam sterilization) is the primary method in veterinary practice. Critical parameters:

• Temperature: 121°C at 15 psi for 15 minutes (gravity displacement) or 132°C for 4 minutes (pre-vacuum)
• Pack density: Overpacking prevents steam penetration
• Chemical indicators: Confirm steam exposure; do not confirm sterility
• Biological indicators: Required periodically to confirm functional sterility (kill Geobacillus stearothermophilus spores)

Packs must be stored appropriately: dry, off the floor, away from moisture sources, and used within the validated shelf life.

3. Surgical team preparation

Surgical hand antisepsis:

Traditional scrub (brush and antimicrobial soap) or alcohol-based surgical hand rub are both validated methods. The goal is to eliminate transient flora and reduce resident flora to minimum levels.

Scrub duration: minimum 3 to 5 minutes for the first case of the day; some protocols allow shorter for subsequent cases with maintained sterility between procedures.

Gowning:

Gowns must be donned without contaminating the outside surface. The back of the gown is considered non-sterile. The sterile zone on a gowned surgeon extends from the chest to table level, and from sleeve cuff to elbow.

Gloving:

Closed gloving technique is preferred over open gloving for reducing hand contamination of the glove exterior. Double gloving is recommended for orthopedic and implant procedures.

Published veterinary data from AJVR (2025) found high rates of aseptic protocol breaches during scrubbing, gowning, and gloving among veterinary students. These breaches were frequently undetected without trained observers. This underscores the need for formal competency assessment rather than assumption of compliance.

Surgical attire:

• Surgical mask: mandatory; covers nose and mouth
• Cap: covers all hair
• Eye protection: recommended for all procedures with fluid exposure risk

4. Operating room environment

The OR represents a controlled-contamination zone. Standards include:

• Traffic control: Minimize personnel entries and exits; each door opening introduces airborne contamination
• Air handling: Positive pressure ventilation with HEPA filtration; air changes per hour appropriate for surgical use
• Surface disinfection: Between-case and end-of-day disinfection with an appropriate agent
• Temperature and humidity: Moderate temperature and controlled humidity reduce airborne microbial survival

For the detail on environmental factors in surgical asepsis, including specific air changes per hour standards, HEPA filtration requirements, and evidence-based guidelines for OR environmental control, that guide covers this domain comprehensively.

5. Intraoperative technique

Maintaining asepsis during the procedure is as important as the preparation preceding it.

Principles:

• Sterile items contact only sterile surfaces
• Non-sterile personnel do not reach across the sterile field
• Any item of doubtful sterility is treated as non-sterile
• Breaks in sterility are acknowledged and corrected immediately

Instrument handling:

Instruments are passed handle-first to surgeons without contaminating working ends. Instruments dropped below the sterile field level are no longer sterile and must be replaced.

Wound irrigation:

At the conclusion of the procedure, lavage of the surgical site removes residual debris, blood clots, and free bacteria before closure. Physiologic saline is the baseline. In higher-risk cases, antiseptic lavage agents targeting biofilm and resistant organisms may be used to further reduce contamination before suturing.

For aseptic technique within surgical asepsis, including the specific intraoperative protocols for sterile field maintenance, instrument handling, and technique violation response, that guide covers the procedural components in depth.

SSI risk stratification in small animal surgery

Not all procedures carry equal infection risk. The traditional surgical wound classification system provides a framework:

Class II through IV procedures require heightened aseptic attention and may warrant antimicrobial prophylaxis in addition to strict aseptic technique.

The OR environment and infrastructure that enables these standards is detailed in the guide on OR standards for surgical asepsis, covering airlock access control, traffic management, and between-case disinfection protocols.

The role of antimicrobial stewardship in surgical asepsis

Surgical site infection prevention is not solely an aseptic technique issue. Antimicrobial stewardship is the complementary discipline.

Prophylactic antibiotics:

When indicated, perioperative antimicrobial prophylaxis reduces SSI risk. Key principles:

• Administer within 60 minutes before incision (most common recommendation)
• Select an agent covering the most likely pathogens for the procedure and site
• Discontinue within 24 hours of procedure completion in most cases (prolonged courses do not reduce SSI and increase resistance risk)

Prophylaxis is not a substitute for aseptic technique. It is an adjunct.

Non-antibiotic approaches:

Surgical site washing and intraoperative antiseptic lavage represent non-antibiotic contamination control strategies that align with antimicrobial stewardship frameworks. Reducing bacterial load at the wound at the time of closure without relying on systemic antibiotics directly supports stewardship goals.

For the errors that most commonly compromise surgical asepsis in small animal practice, the guide on common errors in surgical asepsis documents the most frequent categories with practical prevention guidance for each one.

High-frequency error categories documented in veterinary surgical settings include inadequate patient clipping margins, incorrect gloving technique, instrument contamination from table-edge contact, and drape displacement without replacement. Recognition depends on trained observation, not self-reporting. Structured monitoring programs consistently identify more violations than ad-hoc supervision.

The structured reference tool for perioperative asepsis verification is the checklist to maintain surgical asepsis, which provides a phase-by-phase framework from instrument preparation through wound closure confirmation.

Frequently asked questions

What is the difference between asepsis and sterility?

Sterility means complete absence of all living microorganisms and spores. Asepsis means the absence of microorganisms capable of causing disease. In surgical contexts, sterility is the goal for instruments and drapes. The surgical site itself cannot be sterilized (it is living tissue), so aseptic technique aims to reduce contamination to levels manageable by the immune system.

How long after clipping should surgery proceed?

The shorter the interval between clipping and incision, the better. Immediate pre-surgical clipping is preferred over the previous day's clipping. Recolonization of the surgical site begins within hours of hair removal. Clipping in the OR or immediately before transport to the OR is the current standard.

Is double gloving required in small animal surgery?

Double gloving is strongly recommended for orthopedic and implant procedures due to the higher consequences of glove perforation in these cases. For routine soft tissue procedures, single sterile gloves are standard, though double gloving is never contraindicated and reduces the risk of outer glove perforation being undetected.

When should antimicrobial prophylaxis be used alongside aseptic technique?

Clean procedures in healthy patients generally do not require prophylaxis when aseptic technique is rigorously applied. Clean-contaminated and contaminated procedures warrant prophylaxis. Dirty-infected procedures require treatment-level antimicrobial therapy, not prophylaxis. The decision should be made on a case-by-case basis based on wound class, procedure duration, patient risk factors, and the implant status of the surgery.

Surgical asepsis is not a single protocol applied once. It is a continuous discipline applied across the entire perioperative period, involving every member of the surgical team, every instrument that enters the field, every square inch of the patient preparation, and every second of intraoperative technique. When it holds, outcomes are predictable. When it fails at any point, the consequences can be significant.

Resources

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

• Veterian Key. Principles of Surgical Asepsis. veteriankey.com
• WSAVA 2014. Maintaining a Sterile Operating Environment. vin.com
• IntechOpen. Implementing Good Practice in Aseptic Technique for Surgery in Laboratory Animals. intechopen.com
• AVMA Journals. Aseptic protocol breaches during scrubbing, gowning, and gloving in veterinary students. American Journal of Veterinary Research, 2025. avmajournals.avma.org
• ASPCA Pro. Sterile Surgical Techniques. aspcapro.org

Orthopedic surgery in dogs carries higher SSI rates than most other surgical categories. The combination of complex anatomy, prolonged procedure times, tissue trauma from bone work, and the frequent use of implants creates a surgical environment where asepsis must be applied with particular rigor.

What this covers: The asepsis protocol for orthopedic surgery in dogs, including pre-operative preparation, intraoperative standards, and post-operative wound management. Both implant and non-implant orthopedic procedures are addressed, with specific attention to where requirements differ.Evidence base: TPLO SSI retrospective cohorts; veterinary orthopedic surgical site infection incidence data; intraoperative bacterial contamination survey (Vet Surg, Andrade et al., 2016); MRSP colonization as SSI risk factor.SSI rate context: SSI rates in veterinary orthopedic surgery range from approximately 3% to 18%, with the highest rates in procedures involving implants and joints (TPLO: 0.8 to 14.3%; arthrodesis: up to 25%). These rates are substantially higher than for clean soft tissue procedures (1 to 5%).

Key takeaways

• Orthopedic SSI rates are higher than soft tissue SSI rates across all procedure types.
• MRSP colonization is a documented significant risk factor for orthopedic SSI.
• Prolonged procedure time increases SSI risk; minimize through efficient technique.
• Bone work (saw, drill) generates aerosolized contamination near the sterile field.
• Implant procedures require enhanced asepsis; non-implant procedures meet standard.
• Intraoperative lavage is standard for all orthopedic procedures before closure.

Why orthopedic surgery carries elevated SSI risk

Several procedure-specific factors elevate SSI risk for canine orthopedic surgery beyond the baseline for clean soft tissue procedures:

1. Prolonged procedure time

Longer procedures increase SSI risk through cumulative contamination exposure, personnel fatigue leading to technique lapses, and extended anesthesia duration which may impair immune function. SSI risk increases with each additional hour of surgical time.

2. Bone and soft tissue trauma

Oscillating saws, drills, and osteotomes create significant local tissue trauma. Devitalized tissue is more susceptible to bacterial colonization. Thermal damage from bone cutting can further reduce local tissue viability and host defense.

3. Periosteal and soft tissue dissection

Extensive tissue dissection creates dead space. Blood and tissue fluid accumulation in dead space provides a culture medium for bacteria. Minimizing dead space through careful tissue handling and closure is part of the aseptic technique in orthopedic surgery.

4. Implant presence

When metal implants are used, the minimum infective dose required to establish infection drops dramatically. Implants provide an abiotic surface for biofilm formation that bypasses host immune defense. This is why implant procedures require a higher asepsis standard than non-implant procedures.

5. MRSP colonization

S. pseudintermedius, including MRSP strains, is commensal on canine skin and the most common cause of orthopedic SSI. MRSP colonization of the patient is a documented independent risk factor for SSI (OR 9.0 in one orthopedic cohort study).

Pre-operative asepsis: orthopedic-specific requirements

Patient preparation

Clipping:

Clip immediately before surgery. Clip margins should be generous: for extremity procedures, clip from the body wall to the distal limb. For stifle procedures (TPLO, cruciate repair), this typically means the entire limb from the groin to the paw.

A study by Andrade et al. (Vet Surg, 2016) surveyed intraoperative bacterial contamination in dogs undergoing elective orthopedic surgery, confirming that contamination is common and multifactorial. Generous clip margins reduce the zone of potential surface contamination adjacent to the incision.

Skin antisepsis:

Minimum three-pass centrifugal scrub with CHG-alcohol or PVI-alcohol combination. For limb procedures, the scrub extends to the entire clipped area.

Limb hanging:

After skin antisepsis, the limb is suspended (hung) for sterile draping to allow circumferential draping. The hanging apparatus should not contaminate the prepped site. The foot is typically covered with a sterile cohesive bandage or towel before suspension to reduce contamination from paw surfaces.

Pre-operative MRSP consideration:

For high-risk patients (previous MRSP positive culture, recent antimicrobial treatment, chronic skin disease, prior SSI at same site), pre-operative MRSP screening allows scheduling adjustments, decolonization where protocols exist, and enhanced intraoperative asepsis.

Surgical team preparation

Standard surgical hand antisepsis applies. Double gloving is recommended for all implant orthopedic procedures.

Orthopedic instrument sets:

Confirm all instruments are sterile before case start. Orthopedic instrument sets are often complex with many components; each must have chemical indicator confirmation and pack integrity verification before being opened onto the sterile field.

Intraoperative asepsis: orthopedic-specific requirements

Sterile field management

Draping for limb procedures:

Circumferential draping of the limb is standard for most extremity orthopedic procedures. This requires:

• Limb hanging in a sterile loop or stockinette suspended from an IV stand
• Initial circumferential draping with impervious drape material
• Sterile stockinette or cohesive bandage over the distal limb
• Final draping to isolate the surgical site within the sterile field

Once placed, drapes must not be repositioned. Any draped area contaminated during patient positioning must have a new sterile drape applied.

Powered instrument management:

Oscillating saws and drills generate bone and tissue debris that contaminates the surrounding sterile field. Management strategies:

• Use irrigation during bone cutting to reduce heat generation and debris dispersion
• Use sterile drapes positioned to capture contaminated material where possible
• Surgical team members not directly holding the powered instrument should step back during cutting to reduce contamination exposure

Implant insertion:

The moment of implant insertion into bone is the highest-risk moment for contamination in orthopedic surgery. The implant transitions from the sterile field into the bone canal, and any contamination of the implant surface at this moment cannot be subsequently corrected.

Implant handling standards:

• Grasped only with sterile instruments, never bare gloved hands unless using sterile technique
• Not resting on any surface below sterile field level
• Not touched by non-sterile personnel or instruments at any point

OR traffic:

Enforce strict traffic control throughout. Orthopedic procedures are often long (1 to 3+ hours). The temptation to allow additional personnel entry during extended procedures must be resisted. Each entry increases airborne contamination cumulatively across the procedure duration.

For aseptic technique applied during orthopedic procedures, including the sterile field rules, instrument handling, and personnel behavior standards that govern the intraoperative phase of all surgical procedures, that guide covers the intraoperative technique framework.

Intraoperative lavage

Wound lavage before closure is standard for all orthopedic procedures, both implant and non-implant.

Saline lavage:

Copious pulsatile or syringe-pressure saline irrigation removes:

• Loose bone fragments (sequestra)
• Blood clots and debris that would otherwise remain in dead space
• Free-floating bacteria that accumulated during surgery

Volume: typically 500 mL to 1 L for a single joint procedure; more for larger procedures.

Antiseptic lavage:

For higher-risk procedures (implant placement, MRSP-positive patient, prolonged procedure), antiseptic lavage before closure addresses residual bacterial contamination that saline alone cannot eliminate. Non-antibiotic antiseptic lavage options targeting biofilm-forming organisms have been used in veterinary orthopedic settings to reduce bacteria, biofilm, and resistant organisms before suturing.

This is a non-antibiotic contamination control step aligned with antimicrobial stewardship principles.

For asepsis requirements when implants are involved, including the enhanced asepsis protocol and the clinical rationale for each enhancement in the context of implant-associated infection risk, that guide covers implant-specific asepsis.

Procedure-specific asepsis notes

TPLO (tibial plateau leveling osteotomy)

TPLO is the highest-volume and highest-SSI-rate procedure in veterinary small animal orthopedic surgery. Key asepsis considerations:

• Entire limb prep from groin to paw
• Prolonged procedure time warrants strict OR traffic management
• Bone work with oscillating saw generates significant local contamination
• MRSP risk is the primary driver of treatment-resistant SSI in TPLO patients
• Implant presence (plate and screws) elevates the consequence of any contamination event

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

Fracture stabilization

Trauma patients presenting for fracture repair often have wound contamination from the injury. Wound classification should be assessed before surgery:

• Closed fracture: generally Class I (clean); standard asepsis applies
• Open fracture: Class III (contaminated) or higher; enhanced protocols apply; antimicrobial therapy (not prophylaxis) indicated

Arthroscopy

Arthroscopic procedures have lower SSI rates than open orthopedic procedures. However, fluid distension media must be sterile, instruments must be sterile (high-level disinfection is not sufficient for instruments entering joint space), and skin antisepsis applies to all portal sites.

Joint replacement

Where performed, hip and elbow total joint replacement represents the highest-consequence orthopedic implant procedure. Full implant asepsis protocol, MRSP screening, and antiseptic lavage are all indicated.

For asepsis standards applied to orthopedic cases, including the five-domain surgical asepsis framework and how it applies across the full range of surgical procedures, that guide covers the broader surgical asepsis standard.

Post-operative wound management

Wound monitoring is more intensive after orthopedic surgery than after routine soft tissue procedures, reflecting the higher SSI rate and the greater treatment difficulty when infection does occur.

Monitoring schedule:

• Wound check at 48 to 72 hours post-operatively
• Suture/staple removal at 14 days
• Follow-up radiographs at defined intervals for bone healing assessment

What to monitor:

• Incision: redness, swelling, discharge, dehiscence
• Systemic signs: fever, lethargy, reduced appetite
• Limb use: sudden worsening of weight-bearing may indicate deep SSI

Early SSI (within 30 days): typically reflects intraoperative contamination.Late SSI (30 days to 12 months): may reflect biofilm maturation, licking-related contamination, or hematogenous seeding.

Any suspicion of SSI in an orthopedic patient warrants prompt veterinary assessment, bacterial culture, and sensitivity testing before antibiotic selection.

For breaks in asepsis during orthopedic procedures, including the specific break categories that are most common and consequential in orthopedic settings, that guide covers the break identification and response framework.

Frequently asked questions

Do all canine orthopedic procedures require implants?

No. Many orthopedic procedures are performed without permanent implants: cruciate ligament extracapsular repair, femoral head and neck excision, arthrotomy for joint exploration or fragment removal. Non-implant procedures carry lower SSI risk and do not require all of the implant-specific enhancements. They still require the full standard orthopedic asepsis protocol described above.

How does procedure duration affect SSI risk?

Longer procedures accumulate more contamination events, increase OR traffic needs, and may involve personnel fatigue affecting technique compliance. SSI risk increases measurably with each additional hour of surgical time. Efficient surgical technique that minimizes unnecessary tissue handling and procedure duration is itself an asepsis-related quality variable.

Is post-operative antimicrobial prophylaxis required for orthopedic procedures?

Current evidence and stewardship guidelines in both human and veterinary medicine recommend limiting prophylaxis to the perioperative period (within 60 minutes of incision; discontinued within 24 hours). Extended post-operative antimicrobial courses do not reduce SSI rates and contribute to resistance development. The goal is optimizing intraoperative asepsis and prophylaxis timing, not extending post-operative antibiotic coverage.

Orthopedic surgery in dogs demands asepsis that accounts for longer procedures, more tissue trauma, the specific risks of implants and biofilm, and the prevalence of MRSP as the dominant SSI pathogen. None of these factors are addressed by antibiotics alone. All of them are addressed by rigorous asepsis applied across every phase of the perioperative period.

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
• Wiley Online Library. Surgeon and Patient Preparation to Minimize Surgical Site Complications in CCL Surgery. onlinelibrary.wiley.com
• Springer Nature. Antimicrobial prophylaxis is sufficient for acceptable SSI rate in clean orthopaedic and neurosurgeries in dogs. link.springer.com