After FHO surgery, the false joint that forms in place of the removed femoral head doesn't develop on its own. It forms in response to movement.

Physical therapy is not optional after FHO. It's the mechanism by which the surgery produces a functional outcome. Without consistent rehabilitation, the scar tissue that becomes the false joint forms too tightly, muscles atrophy further, and the leg that was operated on may not recover full use.

Quick answer: Physical therapy after FHO begins within the first 1 to 3 days with passive range-of-motion exercises, progresses to leash walking and sit-to-stands in weeks 1 to 4, and adds hydrotherapy and progressive strengthening in weeks 4 to 12. The goal is to shape the forming false joint, rebuild muscle mass, and restore normal gait. Rehab duration ranges from 8 to 16 weeks depending on the dog.

Key takeaways

• Rehab begins within the first 1 to 3 days: waiting too long allows scar tissue to form incorrectly.
• Passive range-of-motion exercises are the essential first step: they preserve joint flexibility during early healing.
• Sit-to-stands are the most important active exercise for rebuilding hindlimb muscle after FHO.
• Hydrotherapy accelerates muscle rebuilding without stressing the forming false joint.
• Hill walking in later stages efficiently builds hip extension strength.
• Without rehab, FHO outcomes are significantly worse: muscle atrophy and joint stiffness are the main consequences.

Why physical therapy matters more after FHO than most surgeries

Most orthopedic surgeries create a stable repair that heals with rest. FHO is different. The surgery creates a space where a false joint must form from the body's own fibrous tissue. The quality of that false joint depends directly on the movement that occurs during its formation.

Bloomfield Pointe Veterinary Hospital states: "Unlike most orthopedic procedures, dogs and cats with FHOs are recommended to have controlled exercise and physical therapy early after surgery. Physical rehabilitation has been shown to promote early weight bearing and enhanced function post-FHO."

Two dogs who have the same FHO surgery performed identically can have dramatically different outcomes depending on how consistently physical therapy was applied during recovery.

Phase 1 (days 1 to 7): managing early healing and preventing stiffness

Icing

For the first 3 to 5 days, ice the surgery site to manage swelling and reduce inflammation.

Animal Clinic of Billings protocol: "The first 3 to 5 days the surgery limb should be iced 2 to 4 times daily. Place a rolled towel between the limbs so the surgery limb is kept parallel to the floor. Place a lightweight towel between the limb and the ice pack. Ice should be applied for 15 to 20 minutes."

Do not place ice directly on the skin. Keep sessions to 15 to 20 minutes maximum.

Passive range-of-motion exercises (PROM)

PROM begins within the first 1 to 3 days post-surgery, with your vet's instruction.

Royal Canin Academy's rehabilitation protocol for post-FHO dogs notes that PROM for hip extension is particularly important, as regaining active hip extension is the primary rehabilitation goal after FHO.

Step-by-step PROM:

1. Lay your dog on their side, operated leg facing up
2. Place one hand at the hip for support; the other supports just below the knee
3. Gently flex (bend) the hip and knee together, moving slowly toward the dog's belly
4. Hold 3 to 5 seconds at comfortable end range
5. Slowly extend the leg back out
6. Repeat 10 to 15 repetitions per session
7. Perform 2 to 3 sessions daily

Key rules:

• Move slowly. There should be no abrupt movements.
• Stop immediately if the dog vocalizes, tenses up, or tries to pull away
• Never push through resistance or discomfort
• The motion should feel like a gentle, slow pendulum

Gentle walking

Short leash walks for bathroom trips only: 5 to 10 minutes, slowly, on a leash. Let the dog pace. The goal is controlled movement, not distance.

Phase 2 (weeks 1 to 4): building early strength and false joint formation

Controlled leash walking

This is the core exercise of weeks 1 to 4. Walking on a leash at a slow pace encourages the dog to load the operated leg, which is exactly what shapes the forming scar tissue.

Protocol:

• Start: 5 to 10 minutes, 2 to 3 times daily, flat ground
• Increase: 5 minutes per week as the dog tolerates
• Pace: Slow enough that the dog uses the leg with every step. Faster pacing allows the dog to carry the leg.
• Surface: Grass or packed dirt preferred; avoid slippery pavement

Animal Clinic of Billings: "Begin leash walks. Start with 5-minute leash walks 2 to 3 times a day for one week, increase the duration of the walks by 5 minutes each week until your dog is taking 20-minute leash walks without issue."

Sit-to-stand exercises

Sit-to-stands are the single most important active exercise after FHO. They directly target the quadriceps and hip extensors, the primary muscle groups that stabilize the false joint.

How to perform sit-to-stands:

1. Ask your dog to sit in a controlled position
2. Use a treat at nose level to lure them slowly to standing
3. Once fully standing, cue them back to sit
4. Repeat 5 to 10 repetitions per session
5. 2 to 3 sessions daily

Watch carefully: the dog should be using both rear legs equally during the sit-to-stand. If the dog is consistently pushing off the good leg and not using the operated side, this is worth noting and discussing with your vet or rehab therapist.

Start with 5 repetitions and increase to 10 as strength improves. Royal Canin Academy notes that sit-to-stand exercises can be introduced soon after surgery to strengthen hindlimb muscles without the pain associated with full hip extension.

Gentle massage

Light circular massage along the thigh muscles on the operated side, 3 to 5 minutes once or twice daily. This improves local circulation, reduces muscle tension, and helps the dog become more comfortable bearing weight on the leg.

Phase 3 (weeks 4 to 12): progressive loading and advanced therapy

Hydrotherapy

Hydrotherapy is one of the most effective rehabilitation tools available for FHO recovery. Water buoyancy reduces the load on the forming false joint while water resistance provides meaningful muscle engagement.

Animal Clinic of Billings recommends: "Schedule your dog's hydrotherapy sessions 2 or 3 times weekly for the next 4 to 8 weeks."

Types of hydrotherapy:

• Underwater treadmill: The dog walks on a submerged treadmill with water level at the stifle or below. Royal Canin Academy notes that water level at the stifle or lower promotes more functional activity during underwater treadmill sessions. An inclined treadmill setting may also help, though the inclination typically needs to exceed 5% to produce meaningful hip range-of-motion improvement.
• Pool swimming: More cardiovascular and involves greater rotational movement. Usually introduced after underwater treadmill sessions.

Uphill walking

Controlled walking on gentle inclines builds hip extension strength more efficiently than flat-ground walking. The uphill motion requires greater engagement of the gluteal muscles and hip extensors.

Introduce gentle inclines from week 4 to 6 once flat-ground walking is managed comfortably. Progress the incline gradually. Running on hills is not appropriate at this stage.

Balance and proprioception exercises

Balance work activates the stabilizing muscles around the false joint and restores the dog's proprioception (awareness of where the leg is in space).

• Balance disc or wobble board: Standing with hind paws on an unstable surface activates the stabilizing muscles
• Cavaletti poles: Walking over low poles at stride length encourages deliberate hind leg placement
• Weight shifting: Gentle lateral weight shifts while the dog stands encourage loading of the operated side

How physical therapy affects long-term outcomes

The link between rehabilitation compliance and FHO outcomes is clear in the published literature. VCA Animal Hospitals states: "Active dogs often experience better results with FHO than less active dogs. The muscle mass that has been built up through activity helps to stabilize the joint, allowing the dog to regain pain-free mobility more quickly."

Dogs who receive consistent, structured rehabilitation:

• Form more supple, functional false joints
• Maintain better muscle mass
• Return to weight-bearing sooner
• Show less residual lameness at 6 and 12 months
• Require less long-term pain management

Dogs who are insufficiently rehabilitated:

• Form stiffer, more restrictive false joints
• Have more pronounced muscle atrophy
• Take longer to return to functional use
• Are more likely to carry the leg persistently

For how therapy contributes to overall FHO success rates, see how physical therapy improves success rates. For the full recovery timeline that physical therapy supports, see recovery timeline that physical therapy supports.

Working with a certified canine rehabilitation therapist

While many exercises can be performed at home with veterinary guidance, a certified canine rehabilitation therapist (CCRT or CCRP) offers advantages that home programs can't fully replicate:

• Underwater treadmill access: Not available at home
• Gait assessment: A therapist can observe how the dog walks and identify compensation patterns before they become entrenched
• Laser therapy: Low-level laser therapy reduces inflammation and promotes tissue healing; often used in the early post-FHO period
• Individualized program design: Tailored to your dog's specific grade of recovery, size, and pace of progress
• Hands-on technique correction: Ensures PROM and other exercises are done correctly

Even one to two sessions with a rehab therapist to establish correct home technique can meaningfully improve recovery trajectory.

For how physical therapy affects long-term outcomes beyond the immediate recovery period, see how therapy affects long-term outcomes.

For the overall recovery expectations that physical therapy sits within, see overall recovery expectations.

Frequently asked questions

When should I start hydrotherapy after FHO?

Most dogs can begin hydrotherapy 4 to 6 weeks post-surgery, after suture removal and once the incision is fully healed. Royal Canin Academy notes that underwater treadmill use is appropriate after suture removal. Starting before this risks wound contamination. If wound healing is delayed, hydrotherapy start is also delayed.

Can I do all the rehabilitation at home?

Yes, with guidance. PROM, leash walking, sit-to-stands, and massage can all be performed at home following your vet's instructions. The exercises that require specialist equipment (underwater treadmill, laser therapy) need a rehab facility. If a rehab facility isn't accessible, a home program consistently followed produces good results for most dogs.

What if my dog refuses to do the exercises?

Use food motivation for active exercises like sit-to-stands. For PROM, timing matters: do it 30 to 60 minutes after pain medication has taken effect, when your dog is most comfortable. Keep sessions short and positive. Never force the exercises. If your dog consistently resists, contact your vet or a rehab therapist to assess whether pain management needs adjustment.

How long does physical therapy need to continue?

Most dogs complete their primary rehabilitation program by 8 to 12 weeks post-surgery. Some dogs, particularly large breeds or those with delayed recovery, may benefit from continued exercise management for 4 to 6 months. Even after formal rehab is complete, maintaining good muscle condition through regular appropriate exercise contributes to long-term outcome.

FHO gives the body the conditions to form a new joint. Physical therapy determines what that joint becomes. It's the least glamorous part of FHO recovery, and it's the most important. Fifteen minutes of exercises twice a day for ten weeks is a real commitment. What it produces is the difference between a dog who carries the leg and a dog who uses it.

Resources

• Animal Clinic of Billings. FHO Rear Limb Dog Surgery: Post-Operative Rehabilitation Protocol. animalclinicofbillings.com
• Royal Canin Academy. Post Hip Surgery Recovery and Rehabilitation. academy.royalcanin.com
• VCA Animal Hospitals. Femoral Head Ostectomy (FHO) in Dogs. vcahospitals.com
• Bloomfield Pointe Veterinary Hospital. Femoral Head Ostectomy (FHO). bloomfieldpointeveterinaryhospital.com

After FHO surgery, every pound of body weight your dog carries has a direct effect on how the false joint forms, how quickly your dog returns to weight-bearing, and how well the hip functions long-term.

Diet and weight management aren't passive concerns during FHO recovery. They're active outcome variables you control every day.

Quick answer: During the first two weeks of crate rest, reduce your dog's calorie intake by 10 to 15%; activity drops sharply, and maintaining pre-surgery portions leads to weight gain that stresses the forming false joint. As rehabilitation progresses and activity increases, gradually restore calories to match the new activity level. Long-term, maintaining a lean body weight is the most controllable factor in protecting the false joint over the dog's lifetime.

Key takeaways

• Reduce calories 10 to 15% during early recovery: activity drops sharply; pre-surgery portions cause weight gain.
• Weight gain slows false joint formation and increases stress on the healing hip.
• Lean dogs recover faster: they walk sooner, need less pain medication, and rebuild muscle more effectively.
• Calories should increase gradually as rehabilitation progresses and walks lengthen.
• Joint-supportive supplements (omega-3s, glucosamine) complement diet but don't substitute for weight control.
• Long-term lean body weight is the most controllable factor protecting the false joint for years.

Why weight matters so much after FHO

The false joint that forms after FHO is not bone. It's a fibrous cushion of scar tissue supported by the surrounding muscles. Unlike a normal joint or a total hip replacement implant, it has no intrinsic mechanical strength. Its load-bearing capacity depends entirely on the muscle surrounding it and on the body weight pressing down on it.

An overweight dog places more load on the forming false joint at precisely the time when it is most vulnerable. The consequences are direct:

• Scar tissue forms under more stress, potentially producing a denser, less pliable false joint
• The dog is more reluctant to use the leg, increasing muscle atrophy
• Muscle atrophy further reduces false joint stability
• More weight on a poorly muscled false joint creates a feedback loop of worsening function

Lean dogs consistently recover faster, begin bearing weight sooner, and achieve better long-term function. This isn't subjective: it's a consistent finding across FHO outcome research and clinical observation.

Phase 1 (days 1 to 14): adjusting for early recovery

Calorie reduction

During the first two weeks, your dog is in crate rest. Activity drops dramatically compared to any pre-surgery baseline. If you continue feeding the same amount, weight gain is almost certain.

Recommended reduction: 10 to 15% below the pre-surgery daily amount.

For most dogs, this is a small adjustment: if you were feeding 2 cups per day, drop to approximately 1.7 to 1.8 cups. The exact amount depends on the food's caloric density.

Managing reduced or variable appetite

Many dogs have reduced appetite for 1 to 3 days post-surgery as anesthesia clears. This is normal and not a reason for concern.

If appetite is poor in the first few days:

• Offer smaller, more frequent meals (3 to 4 times daily rather than 2)
• A brief transition to a bland diet (boiled chicken and plain white rice) can help if the stomach seems sensitive after anesthesia and medications
• Warm the food slightly: the aroma can encourage eating in a reluctant dog
• Do not add rich foods or high-fat treats, which can cause GI upset

Hydration

Ensure fresh water is always accessible. Some dogs drink less than usual in the first day or two after anesthesia. If your dog hasn't drunk water voluntarily within 12 to 24 hours of coming home, offer water by hand or add a small amount of low-sodium chicken broth.

Phase 2 (weeks 2 to 6): syncing calories with rehab activity

As rehabilitation progresses and leash walks increase from 5 to 20 minutes, calorie needs gradually increase. The goal is to match energy intake to energy expenditure as accurately as possible, keeping the dog lean but not underfueling the muscle-building process.

A practical approach:

• Start of this phase: maintain the 10 to 15% reduction
• By week 4 to 5 (when walk duration has increased meaningfully): restore approximately half the reduced amount
• By week 6 (if activity is progressing well): return to the pre-surgery baseline or slightly below

If the dog is gaining weight despite increased activity, reduce portions. If the dog is losing body condition (ribs easily felt, muscle wasting progressing beyond the operated leg), increase slightly.

Body condition scoring

Ask your vet to assess your dog's body condition score (BCS) at each recheck visit. The BCS scale (1 to 9, ideal at 4 to 5) provides an objective measure of whether your dog is at appropriate weight. An underweight dog won't have the resources to rebuild muscle; an overweight dog places excess load on the false joint.

Phase 3 (weeks 6 to 12+): building toward long-term management

As your dog approaches full activity, the diet transitions from recovery-focused to long-term joint health maintenance.

Portion adjustment to activity level

Match daily portions to daily activity level:

• Longer walk day: slight increase in daily food amount acceptable
• Rest day or reduced activity: reduce portions slightly

Treating the diet as fixed regardless of activity variation is a common cause of slow weight gain over weeks and months.

Joint-supportive diet options

For dogs with ongoing hip conditions (ongoing arthritis risk, multiple joint involvement, older dogs), a prescription joint health diet or senior diet formulated for joint support may be appropriate. Discuss with your vet at the 8 to 12 week recheck whether a diet change makes sense for your dog's long-term needs.

Supplements that support recovery and joint health

Diet alone is the primary tool, but supplements can support the recovery process and long-term joint health.

Omega-3 fatty acids (fish oil)

Omega-3 fatty acids (EPA and DHA) have the strongest evidence base of any joint supplement in dogs. They reduce inflammatory activity in joints and have been shown to improve clinical signs of hip arthritis in multiple published studies.

TPLO Info (which covers orthopedic post-surgical nutrition broadly): Omega-3 fatty acid supplements may reduce inflammation and support joint health post-surgery.

Dosing: Follow the product label for your dog's weight or consult your vet. Fish oil derived from marine sources (salmon oil, sardine oil) contains the EPA and DHA forms most relevant to joint inflammation.

Glucosamine and chondroitin

Support cartilage maintenance and joint fluid quality. The false joint doesn't have cartilage, but adjacent joints and any residual cartilage surfaces benefit from support.

Evidence in dogs is modest but consistent with benefit, particularly for dogs with concurrent hip or stifle arthritis.

Green-lipped mussel

A natural source of omega-3 fatty acids and glycosaminoglycans. Often included in commercial joint support products.

Foods to avoid during recovery

• High-fat table scraps: calorie-dense, easy to add unintentionally; cause weight gain without nutritional benefit
• Rawhides and high-calorie chews: consider these as part of the daily calorie total, not extras
• Grain-free exotic protein diets without veterinary guidance: some have been associated with cardiac concerns in dogs; consult your vet before changing diet type significantly

Long-term weight management: the most durable joint protection

Once the recovery period is complete, maintaining ideal body weight is the most impactful ongoing action you can take to protect the false joint over the dog's lifetime.

Key principles:

• Weigh your dog every 1 to 2 months at home or at the vet
• Adjust portions if weight trends up or down
• Increase low-impact exercise (walking, swimming) rather than increasing food on active days
• Reassess at every annual vet visit whether the current diet type and amount are still appropriate for the dog's age, activity level, and body condition

For how diet and weight affect the overall recovery timeline, see recovery timeline that diet supports.

For how weight management connects to long-term FHO outcomes, see how weight management affects long-term outcomes.

Diet and physical therapy work together as the two most controllable post-FHO outcome variables. For how diet and physical therapy interact to support recovery, see how diet and physical therapy work together.

Recheck schedule for weight monitoring

The SustainableVet post-FHO nutrition protocol recommends formal weight and body condition assessment at:

• Week 2: First suture removal recheck; weight baseline
• Week 6: Rehabilitation progress recheck; adjust feeding plan if weight is trending wrong
• Week 12: Final primary recovery recheck; transition to long-term maintenance

Between formal rechecks, weekly home weighing with a consistent scale gives you a real-time read on whether the current feeding plan is working.

For how diet fits within the broader post-operative care picture, see overall post-operative care.

Frequently asked questions

Should I feed my dog more protein after FHO to help rebuild muscle?

Adequate protein is important for muscle recovery. Most commercial dog foods formulated for adult dogs provide sufficient protein for recovery when fed at appropriate amounts. If your dog is on a very low-protein or restricted diet for other medical reasons, discuss with your vet whether protein intake is adequate for the recovery phase. Increasing protein through meat additions is usually not necessary if the base diet is appropriate.

My dog is refusing to eat after surgery. How long should I wait before worrying?

Reduced appetite for 1 to 3 days is normal after anesthesia and surgery. If your dog hasn't eaten anything meaningful by day 3, or if they're vomiting or showing other signs of nausea, contact your vet. Some dogs need anti-nausea medication to get their appetite back on track, particularly if they're sensitive to NSAIDs.

Can I give my dog joint supplements from the start of recovery?

Most joint supplements are safe to start immediately post-surgery and may support recovery from the beginning. Check with your vet on any specific product, particularly if your dog is on other medications, to confirm there are no interactions. Fish oil, glucosamine, and chondroitin have good safety profiles in dogs.

How do I know if my dog's weight is affecting their recovery?

Signs that weight may be a factor: the dog is reluctant to use the leg despite adequate pain control, rehabilitation progress is slower than expected, or the dog seems to be gaining weight during recovery. Ask your vet to check body condition score at each recheck visit. A BCS above 5 out of 9 during recovery warrants a conversation about diet adjustment.

Weight management during FHO recovery isn't about strict calorie counting or elaborate nutritional science. It's about the straightforward reality that a leaner dog recovers better than a heavier one. Reduce portions during crate rest. Restore them gradually as activity increases. Keep your dog lean long-term. These three steps protect the false joint for years, and they're entirely within your control.

Resources

• TPLO Info. Post-TPLO Surgery Dog Nutrition: What to Feed for a Quick Recovery. tploinfo.com
• Newport Veterinary Referral Hospital. Post-Surgery Pet Care: 10 Foods for Faster Recovery. newportvetrh.com
• VCA Animal Hospitals. Femoral Head Ostectomy (FHO) in Dogs. vcahospitals.com

When your vet recommends FHO surgery, you're agreeing to something that will happen while your dog is under anesthesia and you're in the waiting room. Understanding what actually takes place, step by step, makes the experience less abstract and helps you prepare practically and emotionally.

This guide walks through the full FHO procedure: the preparation before surgery, what happens in the operating room, and what the first hours after surgery look like before your dog comes home. For a broader explanation of what FHO is and what it achieves, see what FHO surgery is.

Quick answer: FHO surgery typically takes 1 to 2 hours under general anesthesia. The surgeon removes the femoral head and neck through an incision over the hip, closes the joint capsule and soft tissue, and sutures the skin. Your dog is monitored in recovery for several hours before discharge. The procedure itself is well-established and considered technically straightforward by veterinary surgeons with orthopedic experience.

Key takeaways

• FHO is performed under general anesthesia: your dog feels nothing during the procedure.
• Pre-surgical bloodwork and X-rays are required to confirm the diagnosis and assess anesthetic safety.
• The procedure takes 1 to 2 hours for most dogs; larger dogs or complex cases may take longer.
• The femoral head and neck are removed completely through a lateral incision over the hip.
• Soft tissue closure is meticulous: the surrounding muscles form the support structure for the false joint.
• Your dog typically stays for several hours post-surgery before discharge with medications and instructions.

Before surgery: the preparation phase

Pre-surgical assessment

FHO is not performed without diagnostic confirmation. Before surgery is scheduled, your vet will complete:

Physical examination:

• Orthopedic assessment of the hip, including palpation for pain on extension and rotation
• Gait analysis
• Assessment of all joints to rule out concurrent disease (Veterinary Practice News notes one-third of dogs referred for hip pain have concurrent stifle disease)

Radiographs (X-rays):

• Standard hip radiographs in dorsoventral positioning to assess the femoral head, acetabulum, degree of arthritis, and joint congruity
• Stifle radiographs if indicated
• Provides the baseline images the surgeon uses for surgical planning and post-operative comparison

Pre-anesthetic bloodwork:

• Complete blood count, chemistry panel, and urinalysis
• Identifies kidney or liver dysfunction that would affect anesthetic drug metabolism
• Essential for senior dogs and any dog with known concurrent health conditions
• Garbizo Animal Clinic: "Our veterinarians will conduct a complete pre-anesthetic assessment, including bloodwork, digital radiographs, and a physical exam to confirm the diagnosis and ensure your pet is a good candidate for the procedure."

The night before surgery

Standard pre-surgical instructions:

• Food: withhold food from midnight (or a specific time your vet designates) before the procedure. The stomach must be empty to reduce aspiration risk under anesthesia.
• Water: some practices permit water until the morning of surgery; follow your vet's specific instructions.
• Medications: ask your vet whether your dog's regular medications should be given the morning of surgery. Some should be given; others should be withheld.
• No bathing or grooming of the surgical site: leave the hair coat as-is. Clipping is done under sterile conditions in the clinic.

Morning of surgery: drop-off

On the day of surgery:

• Bring your dog in at the scheduled time, typically early morning to allow monitoring through the day
• The admissions process includes a brief examination and review of your consent form
• You'll confirm your contact number and the vet's emergency contact protocol
• A brief pre-surgical examination is performed to confirm the dog is in appropriate health to proceed

Most practices will discharge the same day, typically in the late afternoon.

During surgery: what happens in the operating room

Step 1: anesthesia induction

Your dog receives pre-anesthetic medications (a sedative and often a pre-emptive analgesic) to reduce anxiety, lower the anesthetic dose needed, and begin pain management before the skin is cut.

Induction is typically achieved with an intravenous agent. Once unconscious, a breathing tube is placed in the trachea and connected to gas anesthesia for maintenance throughout the procedure.

Monitoring throughout includes:

• Continuous ECG for heart rhythm
• Pulse oximetry for oxygen saturation
• Blood pressure monitoring
• Capnography (monitoring exhaled carbon dioxide)
• Body temperature (dogs lose heat during surgery; active warming is used)

Step 2: positioning and preparation

Your dog is placed in lateral recumbency (on their side) with the affected hip facing up. The surgical area is clipped and prepared using multiple rounds of antiseptic scrub (typically chlorhexidine or betadine alternating with alcohol) to achieve sterile conditions at the skin surface.

Southwest Veterinary Surgical Service notes: "Special care is taken to ensure that the surgery is done under strict aseptic conditions. The dog's hind limb is clipped the day before the surgical procedure, the skin is evaluated for bacterial infections, and blood work and urine testing are performed prior to surgery to screen for infection."

Sterile drapes are applied around the surgical site, leaving only the prepared area exposed.

Step 3: incision and tissue dissection

The surgeon makes an incision along the lateral (outer) aspect of the thigh, directly over the hip joint. The incision length varies with the dog's size.

Using careful dissection, the muscles are separated to expose the hip joint capsule. The goal is to move tissue rather than cut it where possible, preserving the muscle integrity that will later support the false joint.

Step 4: joint entry and dislocation

The joint capsule is incised to access the hip joint directly. The hip is then deliberately luxated (dislocated) to bring the femoral head fully into view.

The round ligament (ligament of the head of the femur, which connects the femoral head to the acetabulum) is severed.

Step 5: femoral head and neck removal

This is the defining step of the FHO procedure.

Using a bone saw or an osteotome (a surgical chisel) and mallet, the femoral head and neck are removed at the base of the neck. PetMD describes it: "Using either a saw or osteotome and mallet, the femoral head and neck are removed."

The surgeon assesses the cut surface to ensure the femoral neck has been completely removed at the appropriate level. Any rough bone edges are smoothed. Complete neck removal is critical: if any neck remains, it can cause continuing bone contact and pain (a recognized cause of revision surgery in published FHO outcome data).

Step 6: soft tissue closure

Closure of the soft tissue around the now-empty socket is performed in layers:

• The joint capsule and periarticular soft tissues are sutured to partially fill the space between the femoral shaft and the acetabulum. This closure helps initiate the environment in which the false joint will form.
• Muscle layers are sutured over the joint capsule in anatomical position
• Subcutaneous tissues are closed
• Skin is closed with sutures or surgical staples

Animal Works Veterinary Surgery: "The surrounding tissues and muscles are left intact and will support the formation of a new fibrous joint over time."

The total operative time is typically 1 to 2 hours. Larger dogs and more complex cases take longer.

After surgery: the hospital recovery phase

Immediate post-operative monitoring

After the surgical site is bandaged, your dog moves to a recovery area. Anesthesia monitoring continues until your dog is fully conscious and able to swallow reflexively.

During this period:

• Body temperature is monitored and supported (dogs are prone to hypothermia after surgery)
• Pain is assessed and additional analgesics administered if needed
• The incision is checked for any immediate bleeding or concerns
• Your dog is kept calm and comfortable in a padded area

Most dogs regain full consciousness within 1 to 3 hours of surgery completion.

Pain management before discharge

Your dog will receive injectable pain medication in the hospital before they go home. This provides a higher level of immediate pain control than oral medications alone and covers the most acute post-surgical period.

By the time you pick your dog up, they should be comfortable enough to walk (with assistance) and oriented to their surroundings.

Discharge: what you receive

At discharge, expect:

• Oral medications: an NSAID (anti-inflammatory) for 7 to 14 days, often gabapentin for 5 to 7 days, and sometimes a short course of an opioid for the first 1 to 3 days
• Written discharge instructions: including activity restrictions, incision care, E-collar use, medication schedule, and when to return for the first recheck
• Emergency contact information: who to call if you have concerns outside business hours
• Recheck appointment: typically at 10 to 14 days for suture removal and incision assessment

What to look for in the first 24 hours at home

The first 24 hours are about settling in and monitoring:

• Drowsiness and disorientation: completely normal as anesthesia clears
• Reluctance to eat: normal on surgery day; offer food in the evening if your dog seems interested
• Not drinking much water: offer water; if they haven't drunk by 24 hours, contact your vet
• Holding the operated leg up: expected for the first days
• Mild incision swelling: expected in the first 48 to 72 hours

For what normal recovery looks like from day one through 12 weeks, see what to expect after surgery.

For the cost of the procedure you've just learned about, see what the procedure costs.

How FHO compares to the procedure you may have been offered instead

If your vet mentioned total hip replacement as an alternative to FHO, the procedures are fundamentally different. FHO removes the femoral head. THR replaces it with a prosthetic implant. Understanding what each involves helps clarify why your vet recommended one over the other.

For the specific indications that led to an FHO recommendation rather than THR, see when FHO is recommended.

For what FHO surgery achieves and what realistic outcomes look like, see success rates for the procedure.

Frequently asked questions

Can I stay with my dog during surgery?

No. FHO is performed in a sterile surgical suite, and no visitors are permitted. You will drop your dog off and receive updates by phone. Most practices will call you when surgery is complete to let you know how it went.

How will I know if something went wrong during surgery?

Your vet will call you as soon as surgery is complete. If any complications arose during the procedure, they'll discuss this with you at that time. Serious intraoperative complications are uncommon with FHO. The most common issue is ensuring complete removal of the femoral neck, which an experienced surgeon confirms before closure.

My dog seems much worse immediately after surgery than before. Is that normal?

Yes, for the first 24 to 48 hours. The dog is in more acute pain than the chronic pain they had pre-surgery, anesthesia affects alertness and coordination, and the leg is being held up rather than used. This is expected. If your dog's condition doesn't begin improving after day 2, contact your vet.

What should I do if I can't reach my vet and something looks wrong?

If you have a concern after hours that you believe requires urgent attention (significant wound opening, obvious neurological signs, inability to rouse your dog), go to the nearest emergency veterinary clinic. Bring your discharge paperwork so they have the surgical context.

FHO surgery itself is the shortest part of the whole process. The decision takes time; the recovery takes weeks. The surgery is one to two hours in the middle. Knowing exactly what happens in those two hours makes the whole experience easier to enter and to explain to the people around you who are also wondering how your dog is doing.

Resources

• PetMD. Femoral Head Ostectomy in Dogs and Cats: How It's Done, Prep, and Recovery. petmd.com
• Animal Works Veterinary Surgery. Understanding Femoral Head Ostectomy (FHO). animalworksvets.com
• Southwest Veterinary Surgical Service. Total Hip Replacement (THR). swvetsurgery.com
• Garbizo Animal Clinic. What to Expect During FHO Surgery for Pets. garbizoanimalclinic.com

"Will this actually work?" is the question most owners ask once FHO is on the table.

The answer depends significantly on which dog you're asking about. FHO success rates vary considerably between small dogs and large dogs, and the published research tells a more nuanced story than a single headline number suggests.

Quick answer: Owner satisfaction after FHO is high: 83 to 96% of owners report positive outcomes in published studies. Clinical functional outcomes are more variable: good-to-excellent results in roughly 63% of cases across all sizes, but significantly higher in small dogs. The single greatest predictor of a good outcome is consistent post-operative rehabilitation. Without it, even technically successful surgeries produce suboptimal functional results. For a full explanation of what FHO involves and how the false joint forms, see what FHO involves.

Key takeaways

• Owner satisfaction is high: 83 to 96% report positive outcomes across published studies.
• Small dogs consistently achieve better functional outcomes than large dogs after FHO.
• Good-to-excellent function in roughly 63% of all dogs across sizes in published research.
• The Global Vet Specialists review found 42% poor outcomes in a large multi-study analysis.
• Post-operative rehabilitation is the most important outcome predictor in a vet's control.
• Muscle mass and activity level before surgery significantly affect recovery trajectory.

Understanding what "success" means in FHO research

Before reviewing the numbers, it's important to understand how different studies define success.

Owner satisfaction: Subjective measure. The owner reports their dog's quality of life has improved. High satisfaction rates (83 to 96%) reflect the fact that eliminating chronic pain is the primary goal, and most dogs achieve this.

Clinical functional outcome: More objective. Assessed through gait analysis, weight-bearing assessment, range of motion measurement, and lameness scoring. This is where the variation is more significant.

A dog can have a satisfied owner and a measurably imperfect gait simultaneously. Both are true, and both matter.

What owner satisfaction data shows

Multiple studies and clinical reviews report owner satisfaction of 83 to 96% after FHO surgery in dogs and cats. This consistently high figure reflects what FHO primarily delivers: pain elimination.

Dogs who were previously limping, struggling to rise, avoiding stairs, and showing signs of chronic discomfort show meaningful improvement after FHO. Most owners observe this improvement clearly and report it positively.

What this number doesn't capture is gait quality, range of motion completeness, or how the dog compares to full pre-disease function.

What clinical outcome research shows

Clinical studies measuring objective function tell a more complex story.

The Off and Matis study (132 dogs, 51 cats)

One of the most rigorous FHO outcome studies used computerized gait analysis, kinematic measurements, radiographs, orthopedic examination, and owner questionnaires. The results:

• Good functional outcome: 38% of animals
• Satisfactory functional outcome: 20%
• Poor functional outcome: 42%

Global Vet Specialists summarizes: "Functional deficits in small, as well as large-breed dogs, resulted from the FHO procedure," noting that the results were less favorable in larger breeds but not exclusively limited to them.

The Duff and Campbell study (267 FHO patients)

This study of 267 dogs found:

• Muscle atrophy at the operated hip in approximately 50% of dogs, persisting even 8 years post-surgery
• Difficulty jumping and climbing stairs was common
• 20% of dogs had hip pain on examination
• 51% had reduced hip extension on the operated side

These numbers represent long-term follow-up, not just the immediate post-operative period.

Simon Vet Surgical clinical summary

A surgical specialist center summarized outcomes: FHO delivers good-to-excellent results in approximately 62.8% of cases. THR, for comparison, achieves excellent function in 80 to 98% of cases.

Why small dogs do better than large dogs

The consistent finding across published research is that small dogs achieve better functional outcomes than large dogs after FHO. The reasons are mechanical:

• Less load on the false joint: A 12 lb dog's false joint bears much less stress than an 80 lb dog's
• Easier muscle compensation: The surrounding muscle doesn't need to work as hard relative to body weight
• Better adaptation to altered mechanics: Small dogs' movement patterns adapt more readily to the false joint

VCA Animal Hospitals notes that the false joint "works very well to support the weight of small animals but may be less effective in large-breed dogs."

For cases where FHO is performed in large breeds (when THR isn't feasible), expectations should be set accordingly: pain relief is likely, full athletic function is less predictable.

Factors that most affect FHO outcomes

Post-operative rehabilitation

This is the most important outcome predictor. Dogs who receive consistent, structured rehabilitation after FHO develop better false joints, maintain better muscle mass, and achieve better functional outcomes than those managed with rest alone.

The false joint forms from fibrous scar tissue. Movement shapes that scar tissue. Without movement, it forms too tightly, limiting range of motion. With movement, it forms into a supple, functional cushion.

Top Dog Health states: "The dog should be encouraged to use the leg immediately post-op in a controlled manner. This is important because the dog now relies on the surrounding musculature to support the hip; if the dog is not weight-bearing, resulting muscle atrophy and shortening will greatly increase the time of recovery and decrease the chances of a desirable return to function."

For how physical therapy improves outcomes, see how physical therapy improves outcomes.

Pre-surgical muscle condition

Dogs with good muscle mass around the hip before surgery recover more quickly and achieve better function. The existing muscle helps stabilize the femur immediately after the head is removed, before the false joint has fully developed.

Inactive or severely atrophied dogs take longer to recover and may have less complete functional return.

Body weight

Both pre-surgical and post-surgical weight affect outcomes. Overweight dogs place more load on the forming false joint, slowing its maturation and risking more strain on the surrounding soft tissue. Maintaining ideal body weight throughout recovery is a genuine outcome variable.

Age and breed

Younger dogs generally have more adaptive musculature and heal more quickly. This doesn't eliminate the size effect (young large-breed dogs still face less favorable prognosis than small dogs), but age is an independent positive factor.

When success rates are highest: cases where FHO works best

FHO consistently achieves its best outcomes in:

• Small to medium dogs under 45 to 50 lbs
• Cats (excellent outcomes in cats across all studies)
• Dogs with Legg-Calvé-Perthes disease (the procedure was originally developed partly for this condition)
• Dogs with hip fractures where reconstruction isn't feasible
• Dogs with bilateral FHO where staged procedures allow each hip full rehabilitation time

For the specific cases where FHO is recommended, see cases where success rates are highest.

How complications affect success rates

Complications are relatively uncommon with FHO but do affect outcomes when they occur. Reported complications include:

• Sciatic nerve irritation or injury (rare; the sciatic nerve runs near the hip joint)
• Infection of the surgical site
• Failure to use the leg due to inadequate pain management or excessive scar tissue formation
• Continued bone-on-bone contact due to incomplete femoral neck removal

For the full complication profile and how to recognize problems early, see complications that affect success rates.

Using success rates to weigh the FHO decision

Success rate data is most useful when interpreted in context. A 63% good-to-excellent rate for all breeds together, and significantly higher rates for small dogs specifically, should be read alongside:

• The dog's size and expected load on the false joint
• The alternative options and their feasibility
• The owner's commitment and capacity for post-operative rehabilitation
• The baseline: a dog in chronic hip pain who is deteriorating has a low quality-of-life baseline that FHO consistently improves in most cases

For a balanced view of what the success rates mean alongside FHO's limitations, see using success rates to weigh pros and cons. For the full long-term outcome picture beyond the immediate post-surgical period, see long-term outcomes beyond success rates.

Frequently asked questions

Is FHO more successful in young or old dogs?

Younger dogs generally adapt more readily to the altered hip mechanics after FHO. Their muscles are more adaptive and their tissue heals faster. However, dogs of all ages have been successfully treated with FHO. Age alone is not a contraindication, and many senior dogs achieve good pain relief even if their functional recovery takes longer.

Why do some dogs still limp after FHO?

Residual limping after FHO can reflect several things: incomplete false joint development due to insufficient rehabilitation, muscle atrophy that hasn't fully resolved, gait compensation patterns that developed before surgery and persist afterward, or ongoing discomfort in the adjacent joints from abnormal pre-surgical weight bearing. Most residual limping improves progressively over 3 to 6 months with continued rehabilitation.

What happens if FHO doesn't produce a good outcome?

For small dogs with unsatisfactory FHO outcomes, ongoing pain management, additional rehabilitation, or acceptance of a reduced functional level are the main paths. For large dogs with poor FHO outcomes, conversion to total hip replacement is technically possible but more complex than primary THR. This is one reason FHO in large dogs should be entered with realistic expectations.

FHO success rates are real and meaningful for most small dogs. The pain relief they deliver is consistent; the functional recovery is usually good. For large dogs, the honest picture from the published research is that outcomes are more variable and a meaningful proportion will have functional limitations. That doesn't make FHO wrong for large dogs when THR isn't feasible; it means the conversation about expectations matters as much as the conversation about the procedure.

Resources

• Global Vet Specialists. Total Hip Replacement vs Femoral Head Ostectomy: Literature Review. globalvetspecialists.org
• Simon Vet Surgical. Hip Dysplasia Surgery in Dogs. simonvetsurgical.com
• Top Dog Health. Femoral Head Osteotomy for Dogs. topdoghealth.com
• VCA Animal Hospitals. Femoral Head Ostectomy (FHO) in Dogs. vcahospitals.com

If your vet has recommended FHO surgery for your dog, the name alone doesn't tell you much. What is actually being removed? What replaces it? Will your dog walk normally again?

This guide explains exactly what FHO surgery is, how the body adapts after the procedure, which dogs benefit most, and what the procedure involves step by step.

Quick answer: FHO (femoral head ostectomy) is the surgical removal of the "ball" portion of your dog's hip joint. By removing the diseased or damaged ball, bone-on-bone pain is eliminated. The dog's body then forms a false joint of scar tissue and muscle that allows comfortable movement. It's most effective in small to medium dogs and is considered a salvage procedure rather than a full joint reconstruction.

Key takeaways

• FHO removes the femoral head and neck: the ball of the ball-and-socket hip joint is permanently taken out.
• A false joint forms after surgery: scar tissue and muscle create a cushioned connection that allows movement.
• Pain relief is the primary goal: eliminating bone-on-bone contact removes the source of chronic hip pain.
• Best results in dogs under 50 lbs: small dogs form the false joint more effectively than large breeds.
• Rehabilitation is essential: early, controlled movement after surgery is critical to a good outcome.
• FHO is a salvage procedure: it's a last-resort approach when the hip joint can't be repaired or replaced.

The anatomy involved: what a normal hip looks like

Your dog's hip is a ball-and-socket joint. The femoral head, the rounded top of the thigh bone (femur), sits inside the acetabulum, a cup-shaped socket in the pelvis.

In a healthy hip:

• The femoral head is covered in smooth cartilage
• It fits snugly inside the acetabulum
• Movement is smooth and pain-free
• Ligaments and the joint capsule hold everything in place

When this system breaks down, due to hip dysplasia, fracture, Legg-Calvé-Perthes disease, or severe arthritis, the ball and socket grind painfully against each other with every step. This is the pain FHO is designed to eliminate.

What FHO surgery actually does

FHO removes the femoral head and neck entirely. What remains is the shaft of the femur and an empty acetabulum (socket) with no ball inside it.

According to VCA Animal Hospitals: "This removes the ball of the ball-and-socket joint, leaving just an empty socket. The muscles of the leg will initially hold the femur in place and, over time, scar tissue will form between the acetabulum and the femur to provide cushioning."

This cushioning layer of fibrous tissue is called a pseudarthrosis or false joint. It doesn't look like a normal hip joint on X-ray and it doesn't function exactly like one, but in most small to medium dogs it provides enough stability and padding for pain-free daily movement.

FHO is also known as FHNE (femoral head and neck excision). You may hear both terms used interchangeably.

What conditions lead to FHO

FHO is used when the hip joint is beyond repair or replacement due to the dog's size, finances, health status, or the specific nature of the joint damage. Common indications include:

Hip dysplasia: The most common indication. In dogs with severe hip dysplasia where conservative management has failed and THR is not feasible, FHO removes the source of pain.

Femoral head or neck fractures: Traumatic fractures that can't be repaired internally are often best managed with FHO, particularly in small dogs.

Legg-Calvé-Perthes disease: A condition of the juvenile hip where the femoral head loses blood supply and begins to collapse. Common in small breeds under 25 lbs. FHO removes the deteriorating bone and resolves the pain.

Coxofemoral luxation: A dislocated hip that cannot be maintained in position by closed reduction or internal fixation is sometimes managed with FHO.

Severe osteoarthritis: End-stage hip arthritis causing pain that can't be controlled with medication in a dog who isn't a THR candidate.

For the signs that indicate your dog may need this surgery, see signs your dog may need FHO.

Understanding when FHO is the right recommendation rather than other options is closely tied to the specific clinical situation. For the full criteria that guide the FHO recommendation, see when FHO surgery is recommended.

The procedure: what happens during FHO surgery

FHO is performed under general anesthesia. The steps:

1. Pre-surgical evaluation: Bloodwork, radiographs, and a physical exam confirm the dog is a suitable surgical candidate and that anesthesia is safe.

2. Positioning: The dog is positioned on their side with the affected hip facing up.

3. Incision: A cut is made along the side of the thigh, over the hip joint. Muscles in the area are gently moved aside to access the joint.

4. Joint capsule entry: The surgeon opens the hip joint capsule and deliberately luxates (dislocates) the hip to expose the femoral head and neck.

5. Bone removal: Using a bone saw or osteotome, the femoral head and neck are removed cleanly. The cut is made at the base of the neck to remove the entire ball and leave a smooth, flat surface.

6. Closure: The joint capsule and surrounding soft tissues are sutured closed. Skin is closed with sutures or staples. The procedure typically takes 1 to 2 hours.

According to PetMD: "By removing the femoral head and neck, bone-on-bone pain within the hip joint is reduced or eliminated."

How the false joint forms

After surgery, the femoral shaft floats free in the space where the ball once connected to the socket. The surrounding muscles hold the femur loosely in position.

Over the following weeks to months, the body fills this space with fibrous scar tissue. This scar tissue matures into the false joint. VSX Veterinary Surgery notes: "As the body heals, scar tissue will develop, creating a false joint that is more comfortable and results in better mobility than the diseased joint."

The false joint doesn't form passively. It requires the dog to use the leg after surgery. Controlled early movement is what shapes the scar tissue into a functional, supple cushion rather than a tight, restrictive mass. This is why post-operative rehabilitation, including gentle range-of-motion exercises and early leash walking, is critical.

Which dogs benefit most from FHO

Small to medium dogs (under 45 to 50 lbs)

VCA Animal Hospitals notes: "This procedure is primarily recommended for small dogs (under approximately 45 pounds) and cats, especially those who are at a healthy weight. The false joint that is created in an FHO works very well to support the weight of small animals."

In small dogs, the surrounding muscle is strong enough relative to body weight to provide good stability. The false joint functions effectively, and most small dogs return to excellent pain-free movement.

Cats

FHO is very commonly performed in cats for hip dislocation and other hip conditions. Cats form excellent false joints and typically recover well.

Large dogs when THR isn't possible

FHO can be performed in large dogs when total hip replacement is not feasible due to financial constraints, anesthetic risk, or other health factors. Results are less predictable than in small dogs, and residual gait abnormality is more common, but pain relief is still usually achieved.

Top Dog Health notes: "Despite the lack of a normal hip joint following FHO surgery, most dogs do surprisingly well after the procedure, but results can vary depending on the patient's size and post-operative rehabilitation."

How FHO compares to total hip replacement

FHO and THR both treat severe hip conditions but do so very differently:

For the full comparison including long-term outcomes and cost breakdown, see FHO vs total hip replacement comparison.

For information on how much FHO costs, see how much FHO costs.

What to expect after FHO surgery

The recovery from FHO is different from most orthopedic surgeries. Rather than strict crate rest, early controlled movement is encouraged from the first few days post-operatively. The false joint needs movement to form correctly.

General recovery milestones:

• Days 1 to 7: Short leash walks for bathroom trips; passive range-of-motion exercises begin
• Weeks 1 to 4: Gradually increasing leash walk duration; physical therapy exercises introduced
• Weeks 4 to 8: Progressive activity increase; building muscle mass
• Weeks 8 to 16: Most dogs reaching functional recovery

For the complete recovery overview, see what to expect after FHO surgery.

For FHO success rates, see FHO success rates.

Frequently asked questions

Will my dog walk normally after FHO?

Many small dogs return to very comfortable, functional movement after FHO. Whether this looks "normal" depends on muscle development during recovery and the dog's commitment to rehabilitation. Some dogs, particularly large breeds, may have a visible gait difference. Pain relief is almost universally achieved in appropriate candidates.

Is FHO reversible?

No. Once the femoral head and neck are removed, they cannot be returned. If FHO outcomes are unsatisfactory in a large dog, total hip replacement can sometimes be performed afterward, though this is technically challenging. The irreversibility of FHO is one reason proper patient selection matters before proceeding.

How long does the surgery take?

FHO typically takes 1 to 2 hours depending on the dog's size, the specific hip condition, and whether any complications arise during the procedure.

Is FHO painful for dogs?

The surgery is performed under general anesthesia, so your dog feels nothing during the procedure. Post-operative pain is managed with analgesics and anti-inflammatory medication. The goal is for the dog to be comfortable enough to begin gentle movement within days of surgery.

FHO is one of the most counterintuitive procedures in veterinary orthopedics: the solution to a painful joint is to remove the joint entirely and let the body build a replacement from scar tissue. For the right dog, it works remarkably well. Pain relief is the primary outcome, and for a dog who has been suffering through deteriorating hip pain, that change can be dramatic.

Resources

• VCA Animal Hospitals. Femoral Head Ostectomy (FHO) in Dogs. vcahospitals.com
• PetMD. Femoral Head Ostectomy in Dogs and Cats. petmd.com
• VSX Veterinary Surgery. Femoral Head and Neck Ostectomy. vsxvet.com
• Top Dog Health. Femoral Head Osteotomy (FHO) for Dogs. topdoghealth.com

FHO surgery is generally safe and well-tolerated, but complications do occur. Knowing what to watch for, how to recognize a problem early, and how serious each type of complication actually is helps you respond appropriately without either missing a real problem or panicking over normal post-surgical healing.

Quick answer: The most common FHO complications are muscle atrophy from insufficient rehabilitation, reduced range of motion from excessive scar tissue, and persistent lameness. Less common but important complications include surgical site infection and sciatic nerve irritation. Major complications requiring surgical intervention occur in approximately 13% of cases, based on the JAVMA 2025 study. Most complications are manageable with early recognition and appropriate response.

Key takeaways

• Muscle atrophy is the most preventable complication: it results from inadequate rehabilitation.
• Persistent lameness beyond 3 to 4 months should be evaluated; it may indicate inadequate muscle development or residual bone contact.
• Infection is uncommon but serious: spreading redness, discharge, or fever require same-day vet contact.
• Sciatic nerve injury is rare but produces a distinctive knuckling or dragging of the paw.
• Bone spur development can cause recurring bone-on-bone contact and may require revision surgery.
• JAVMA 2025: 33.8% minor complications, 13.2% major, 4.4% surgical revision in 68 FHO cases.

Published complication rates: what the research shows

The JAVMA 2025 retrospective study of 68 FHO cases across four hospitals provides the most current complication data:

• Minor complications (no additional surgery or medications required): 33.8% of cases, including persistent lameness not requiring additional pain medication (17 cases), incisional irritation (2), anxiety (2), seroma (1), and persistent resistance to limb extension (1)
• Major complications requiring intervention: 13.2% of cases, including GI upset (3 cases), infection (1), persistent lameness requiring additional pain medications (2), and surgical revision (3)
• Surgical revision required: 4.4% of cases; all three revision cases involved bony contact from bone spur development

Top Dog Health summarizes the most common complications across the literature: "decreased range of motion and mobility in the leg, muscle atrophy, loss of function, limb shortening, and infection."

Complication 1: Muscle atrophy

What it is

Muscle atrophy is the loss of muscle mass in the thigh and hip region of the operated leg due to reduced use. Some degree of muscle atrophy before surgery (from the pain-related period) and immediately after surgery (from rest) is expected. The complication is when muscle loss is excessive or fails to reverse with rehabilitation.

Why it happens

• Inadequate or delayed rehabilitation after surgery
• Insufficient pain control preventing the dog from using the leg
• Owner non-compliance with exercise protocol
• Pre-existing severe atrophy before surgery that wasn't addressed

What you'll see

• Visible asymmetry: operated thigh is noticeably smaller or thinner than the other side
• The dog consistently avoids the leg even after the expected recovery period
• Reduced confidence using the leg on uneven ground or during transitions

What to do

Muscle atrophy after FHO responds to structured rehabilitation. Begin or intensify the following:

• Controlled leash walking: slow, on flat ground, at a pace that encourages the dog to bear weight on the leg
• Sit-to-stands: the most targeted exercise for the hip extensors and quadriceps
• Hydrotherapy (underwater treadmill): rebuilds muscle without joint loading
• Consistent daily effort for several weeks

If significant atrophy persists despite 4 to 6 weeks of consistent rehabilitation, consult a certified canine rehabilitation therapist for a structured program.

For how rehabilitation directly addresses and prevents muscle atrophy, see post-op care that reduces complications.

Complication 2: Reduced range of motion / scar tissue stiffness

What it is

Scar tissue naturally forms as the false joint develops. If this scar tissue forms excessively or in a restrictive pattern, it can limit how far the hip can flex and extend. The result is a stiff gait, difficulty sitting fully, and reduced hip extension during walking.

Why it happens

• Insufficient movement during the early recovery phase
• The false joint forms tightly due to inadequate early range-of-motion exercises
• Large dogs may be more prone due to the greater forces involved in false joint formation

What you'll see

• The dog's operated leg appears stiff during walking
• The dog has trouble sitting squarely
• On observation, the hip doesn't extend fully during trotting
• Resistance when the leg is gently extended

What to do

• Passive range-of-motion (PROM) exercises should begin within the first 1 to 3 days post-surgery to prevent this
• If stiffness develops, intensive PROM, gentle stretching, and hydrotherapy are the primary interventions
• Laser therapy at a rehabilitation facility can help reduce scar tissue density
• If range of motion stays limited beyond 8 to 10 weeks, a referral to a certified canine rehabilitation therapist is appropriate

Complication 3: Persistent lameness

What it is

Mild limping in the first 2 to 4 weeks is expected. Persistent lameness beyond 4 to 6 months, or lameness that worsens after a period of improvement, is a complication.

Causes

• Inadequate muscle development (the most common cause)
• Residual bone contact from incomplete femoral neck removal
• Bone spur development causing secondary bone contact (as seen in the JAVMA 2025 revision cases)
• Pain from adjacent joint disease developing due to compensation patterns

What you'll see

• Consistent limping or shortened stride on the operated leg beyond the expected recovery period
• Worsening lameness after a period of apparent improvement
• The dog avoids loading the operated leg in activities like going upstairs

What to do

• A vet assessment with radiographs is the appropriate response to persistent lameness
• Radiographs can identify whether bone contact is occurring from residual neck bone or bone spur formation
• If no bony issue is identified, intensify rehabilitation targeting the hip extensors
• If bone contact is confirmed, surgical revision may be needed (as in the 4.4% of JAVMA cases)

For how complications affect the recovery timeline, see how complications affect the recovery timeline.

Complication 4: Surgical site infection

What it is

Infection at the FHO incision site. This is an uncommon complication but requires prompt attention when it occurs.

Why it happens

• Licking the incision (most common cause): introduces bacteria directly into the healing wound
• Environmental contamination of the incision site (walking through dirty water, rolling in grass)
• Systemic factors reducing immune response

What you'll see

Early infection signs:

• Redness extending beyond the incision edges
• Increased heat around the incision
• Yellow, green, or creamy discharge from the incision
• Foul odor from the wound or bandage
• The dog's interest in the incision increases

Systemic signs of deeper infection:

• Fever
• Lethargy
• Reduced appetite
• Marked worsening of lameness

What to do

Contact your vet the same day if you see any of these signs. Superficial infection is treated with antibiotics and local wound care. Deeper infections may require more intensive treatment. Do not wait to see if it resolves on its own.

Prevention: The E-collar must be worn at all times when you can't directly supervise your dog. This is the single most effective infection prevention step in your control.

Complication 5: Sciatic nerve injury

What it is

The sciatic nerve runs near the hip joint and can be affected during or after FHO surgery. Sciatic nerve injury is rare but serious. PetMD notes: "Other risks include infection of the surgical site and damage to the sciatic nerve, which runs near the hip joint."

Why it happens

• Surgical trauma to the nerve during the procedure (uncommon with experienced surgeons)
• Post-operative inflammation or swelling pressing on the nerve
• Scar tissue formation affecting nerve function during healing

What you'll see

• Knuckling: the dog places the top of the paw on the ground rather than the pads (the paw is folded under)
• Dragging: the dog drags the paw during walking
• Reduced withdrawal reflex: reduced or absent response when the paw is pinched
• Muscle weakness: more pronounced than expected for the recovery phase

What to do

Sciatic nerve signs warrant same-day veterinary assessment. Mild cases (from post-operative inflammation) often resolve with time and anti-inflammatory medication. More significant injuries require neurological assessment. Protective paw boots can prevent abrasion to a knuckling limb while recovery is ongoing.

Complication 6: Seroma

What it is

A seroma is a pocket of sterile fluid that accumulates under the skin near the incision. It appears as a soft, fluctuating swelling beneath the incision site.

Why it happens

• Normal response to surgical tissue disruption
• Excessive activity in the early recovery period increasing fluid production
• Inadequate rest

What you'll see

• Soft, puffy swelling near or below the incision
• Not particularly hot or painful to the touch
• No discharge or odor (distinguishes it from infection)
• Typically appears in the first 1 to 2 weeks

What to do

Most seromas are monitored rather than immediately treated. Strict rest reduces fluid production. Contact your vet to confirm the diagnosis. If the seroma is large, under significant tension, or if you're unsure whether it's a seroma or infection, veterinary assessment is appropriate.

Complication 7: Gastrointestinal upset

The JAVMA 2025 study found GI upset as the most common major complication (3 of 9 major complication cases). Post-surgical GI upset in dogs is typically related to:

• NSAIDs given without food (can irritate the gastric mucosa)
• Anesthesia effects on gut motility
• Stress-related gut changes in the perioperative period

Prevention: Always give NSAIDs with food. A bland diet for the first few days post-surgery reduces GI stress. If vomiting or diarrhea occurs after starting post-operative medications, contact your vet: a different medication protocol or temporary medication adjustment may be needed.

For how complications compare to normal recovery expectations, see normal expectations vs complications.

Complication recognition: quick reference

For guidance on cases where complication risk is considered in the recommendation framework, see cases where complication risk is considered.

For how post-surgical care directly reduces complication risk, see how complications affect success rates.

Frequently asked questions

My dog is limping at week 6. Is this a complication?

Some limping at week 6 is still within the expected recovery range, particularly in large breeds or dogs with pre-existing muscle atrophy. If the lameness is clearly improving week over week, it may not be a complication. If it has plateaued or worsened, a vet assessment is appropriate.

Is it normal for the operated area to feel warm for several weeks?

Some warmth at the surgical site in the first 1 to 2 weeks is normal tissue healing. Warmth that persists beyond 2 to 3 weeks, or that increases after a period of improvement, is worth checking. This could indicate ongoing inflammation, infection, or other issues.

My dog's paw seems to fold under when walking. Should I be worried?

Yes, this warrants same-day veterinary attention. Knuckling (paw folding under) can indicate sciatic nerve involvement. It can also reflect neurological problems unrelated to the surgery. Either way, it needs professional evaluation.

Complications after FHO are real, and some are serious. But most are recognizable early, and most respond well to prompt attention. The combination of daily incision monitoring, consistent rehabilitation, adequate pain control, and E-collar compliance addresses the majority of complication risk directly. Know what to watch for, and don't hesitate to contact your vet when something looks wrong.

Resources

• JAVMA. Acute vs. chronic coxofemoral disease: FHO complications and outcomes. avmajournals.avma.org
• Top Dog Health. Femoral Head Osteotomy for Dogs. topdoghealth.com
• PetMD. Femoral Head Ostectomy in Dogs and Cats. petmd.com