The short version

An FHO removes the ball of the hip, and the body grows a false joint in its place from muscle and scar tissue. That false joint only forms well if the leg gets used, so the old instinct to rest a surgical patient works against you here. Early, gentle movement is the treatment. Cats and small dogs usually do very well; bigger dogs need more structured rehab to rebuild the muscle that now does the joint's job. Most pets are bearing weight within a few weeks and back to near-normal function over the months that follow.

Quick facts

  • What it is: a femoral head ostectomy, also called femoral head and neck excision, removes the head and neck of the thigh bone so there's no painful bone-on-bone contact. A false joint of fibrous tissue and muscle, called a pseudoarthrosis, takes over the job.
  • Who gets it: dogs and cats of almost any age. It commonly follows a hip fracture or dislocation that can't be repaired, the end stage of hip dysplasia, and Legg-Calvé-Perthes disease in small-breed dogs. FHO is a routine, well-tolerated procedure in cats.
  • Hallmark of recovery: the pet moves from toe-touching, to partial weight-bearing, to loading the leg fully over the first weeks. A slightly shorter stride or mild limp on that side can stay for life and usually doesn't matter.
  • How progress is judged: hands-on checks of hip range of motion, thigh muscle measured with a tape, and how evenly the pet loads the leg on the floor and on video.
  • Treatment: early controlled movement, weight-bearing exercises, hydrotherapy, and muscle-building physiotherapy, with pain relief in the first weeks. The work is retraining the leg, not resting it.

What FHO is, and why the leg must move

An FHO, or femoral head ostectomy, removes the ball at the top of the thigh bone along with the neck below it. With the damaged joint surface gone, there's no more grinding of bone against bone, which is where the pain came from. In its place the body builds a false joint: a cushion of scar tissue held and moved by the muscles around the hip. Vets also call it femoral head and neck excision, or a pseudoarthrosis once it has formed.

It's usually a salvage operation, chosen when a hip can't be saved or when a full replacement isn't the right fit for the pet or the family's budget. The common reasons are a hip fracture or dislocation that can't be repaired, the end stage of hip dysplasia, and Legg-Calvé-Perthes disease in small-breed dogs. It also follows some cases treated after a fracture near the hip.

Here's what makes FHO recovery different. The result depends on the false joint, and the false joint depends on movement. Muscle is what holds the new joint together and drives it, so a leg that sits idle grows a stiff, weak, poorly shaped joint. The thigh muscle that wasted while the hip was painful has to be rebuilt, and it rebuilds by working. Cage rest, the reflex for most surgeries, is the one thing that reliably slows an FHO down.

Why rest is the enemy here

With most orthopaedic surgeries you protect the repair and limit movement. FHO is the reverse. There's nothing to protect and nothing to break loose, so early controlled use is the goal from the first days. In one study, dogs that started physiotherapy about two days after surgery loaded the leg sooner and moved better. The risk isn't doing too much too soon; it's doing too little for too long, letting the muscle waste and the joint stiffen while everyone waits for the leg to heal on its own.

Comfort and wound healing

Days 0-7

The first week is about pain control and keeping the incision clean and undisturbed. Your pet may barely touch the foot down at first, and that's normal. Short, calm toilet trips on a lead, non-slip footing, and the prescribed pain relief set the stage. Gentle passive movement of the hip often begins within a day or two on your vet's guidance.

Getting the leg moving

Weeks 1-3

As the wound settles, the focus shifts to getting the hip bending and the foot touching down with each step. Slow lead walks, passive range-of-motion, and simple weight-shifting help the pet trust the leg. Toe-touching turns into partial weight-bearing. This is where hydrotherapy earns its place, because water lets the leg move and load without the full force of standing on hard floors.

Building the false joint through use

Weeks 3-8

Now the real work starts. The false joint forms and strengthens in response to load, so the leg is asked to do more: longer walks, gentle slopes, sit-to-stand practice, and targeted exercises that rebuild the thigh and gluteal muscle. Underwater treadmill sessions retrain a normal stride. Progress is measured by how evenly the pet loads the leg and how the muscle fills back out.

Full function

Months 2-4+

Most pets are using the leg freely by now, with muscle close to matching the other side. A slightly shorter stride or a mild limp after hard play can remain, and for most families that's a fair trade for a pain-free hip. Keeping the muscle strong for life, through regular activity, protects the result.

2 daysafter surgery, rehabilitation can safely begin
90%+of owners are happy with their pet's function after FHO
3things predict the best result: early weight-bearing, kept muscle, lower body weight

What good recovery looks like

Recovery isn't a straight line, but there are markers that tell you the leg is coming back. In the early weeks you're watching for the foot to touch down, then take weight, then move through a fuller range. A few permanent quirks are normal and nothing to worry about.

  • Toe-touching in the first days, turning into partial then full weight-bearing over the following weeks
  • The thigh on the operated side slowly filling back out as muscle rebuilds
  • A wider, more even stance when standing still, rather than holding the leg off the ground
  • Willingness to sit, stand, and climb a low step without help
  • A slightly shorter stride or occasional mild limp on that side, which often stays for life and rarely causes trouble
  • A little stiffness after a big day of activity that eases with gentle movement
  • For cats: a return to jumping and normal litter-box use, often sooner than owners expect

If the leg is being used more from week to week, recovery is on track. A plateau, or a step backwards, is worth a call, and we cover those signs further down.

How dogs and cats differ

Both species do well with FHO, but recovery looks different. Cats and small dogs carry less weight through the hip and adapt to the false joint easily, often regaining near-normal function on a light rehab plan. Cats in particular tend to sort themselves out through movement they choose on their own, though a structured plan still helps the ones that guard the leg and stiffen up.

Larger dogs ask more of the false joint, so muscle matters more and formal rehab does more of the heavy lifting. Body weight, how much muscle the pet kept before surgery, and how early the leg gets used all shape the result. A lean, active patient has the edge, which is why weight management and consistent exercise are part of the plan from the start.

How AURA helps

AURA's job after an FHO is to get the leg working early and to rebuild the muscle that now runs the joint. We build the plan around your pet's size, temperament, and how the surgery went, then adjust it week to week based on how the leg is loading.

PhysiotherapyThe backbone of FHO recovery. We start with passive range-of-motion and gentle weight-shifting to wake the leg up, then progress to sit-to-stand work, controlled walking, and targeted exercises that rebuild the thigh and gluteal muscle. Because the false joint forms through use, the programme pushes function steadily while staying inside your pet's comfort. We also coach you through the daily home exercises that make or break the result.
HydrotherapyWater carries part of your pet's weight, so the leg can move through a full range and start loading long before it could manage the same work on hard ground. Swimming builds hip and thigh muscle with low impact, which suits the early and middle weeks when land exercise is still limited. It also helps the anxious patients who guard the leg on dry land.
Underwater treadmillOnce the leg is taking weight, the treadmill retrains a normal walking pattern under controlled load. Raising the water lightens the leg; lowering it adds work as the muscle comes back. It's the bridge between early swimming and full land exercise, and where a lot of the stride correction happens before your pet is back to ordinary walks.
Pain managementComfort in the first weeks lets the leg get used, and use is the whole point. Laser therapy supports the healing tissue around the surgery site and eases soreness so your pet is willing to move. We pair it with manual therapy for the secondary tension that builds in the back and opposite leg while your pet favours the operated side.

Just had an FHO booked, or recovering from one now?

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Managing recovery at home

01

Make the floors safe

Singapore homes are full of slippery tile and marble, and a pet relearning to load a leg will skid and lose confidence fast. Lay runners or yoga mats along the routes your pet uses most, from the bed to the water bowl to the door. Block access to stairs, and stop any jumping onto sofas or beds in the early weeks. Good footing does as much for early weight-bearing as any exercise.

02

Encourage use over cage rest

The hard part is trusting that movement is the medicine. Follow your rehab team's plan of short, frequent lead walks and simple exercises rather than shutting your pet in a crate all day. Keep sessions little and often, and let your pet set the pace within the plan. If your pet is guarding the leg and won't use it, that's a reason to check in, not a reason to rest longer.

03

Keep the muscle for life

The false joint stays comfortable as long as the muscle around it stays strong. Once recovery is done, keep your pet lean and active with regular walks, play, and the occasional top-up rehab session for the pets that need it. Extra weight loads the hip and undoes hard-won progress, so keeping your pet trim is the single best long-term habit.

Outlook

The outlook after FHO is good, and for cats and small dogs it's very good. Most pets return to comfortable, near-normal use of the leg and get back to the life they had before the hip went bad. The trade-offs are usually cosmetic: a slightly shorter leg, a mild limp after hard exercise, a little less range at the hip. Most owners barely notice once their pet is moving freely.

Bigger dogs have a wider range of results. Some do beautifully; others keep a more noticeable limp, especially if muscle was already wasted before surgery or if rehab was cut short. This is where consistent, early rehab pays off, because the muscle you build is doing the work the joint used to do. Weight, effort, and time all shape where a big dog lands.

Honest expectation: this is a salvage procedure, not a rebuilt hip. It trades a painful joint for a pain-free false one, and it does that job well for most pets. What you put into the first two months of rehab is roughly what you get back.

What to ask your vet

Worth a screenshot before the appointment:

  • Given my pet's size and weight, how predictable is the outcome likely to be?
  • How soon after surgery can rehabilitation and weight-bearing start?
  • What pain relief will my pet be on, and for how long?
  • How much muscle had already wasted before surgery, and does that change the plan?
  • What should I stop my pet from doing in the first few weeks, and what should I encourage?
  • At what point should I be concerned that recovery has stalled?

When to call your vet

Most FHO recoveries are smooth, but call your vet or your rehab team promptly if any of these show up:

  • The leg is being used less from week to week, not more: recovery may be stalling and the plan needs a review
  • Swelling, heat, discharge, or a bad smell at the incision: possible wound infection
  • Sudden refusal to bear any weight after a period of improvement: a setback that needs checking before you push on
  • Pain that isn't settling with the prescribed relief: the dose or the plan may need adjusting
  • The thigh muscle keeps shrinking instead of filling out: the leg isn't being loaded enough and rehab needs to step up
  • Your pet seems flat, off food, or unusually withdrawn: worth a call, since pain and post-op complications can show up this way

Common questions

How soon should my pet start moving after an FHO?

Sooner than you'd think. Unlike most orthopaedic surgeries, there's no repair to protect, so gentle movement usually begins within a day or two under your vet's guidance. Early controlled use is what tells the body to build a strong false joint. In one study, dogs that started physiotherapy around two days after surgery loaded the leg sooner and moved better. That doesn't mean running or jumping. It means short lead walks, passive range-of-motion, and encouraging the foot to touch down. Rest has its place in the first days for the wound to heal, but the leg needs to work.

Will my pet limp forever?

Often there's a slight, permanent difference, and usually it doesn't matter. The operated leg ends up a touch shorter because the femoral head and neck are gone, so many pets keep a mild limp or a shorter stride on that side, more noticeable after hard play. What you're aiming for is a comfortable, freely used leg, not a cosmetically perfect gait. Cats and small dogs frequently move so well that owners forget which side was operated on. Bigger dogs are more likely to keep a visible limp, especially if rehab was light or muscle was already wasted before surgery.

My vet said to rest my pet, but this page says to move. Which is right?

Both, at different times and for different reasons. The incision needs a few calm days to heal, so early rest is about the wound, not the joint. Beyond that, the false joint only forms well with use, so your rehab plan will have your pet moving in a controlled way within the first week or two. If you're unsure, ask your vet specifically about weight-bearing and range-of-motion timing. The mistake we see most is strict cage rest for weeks, which lets the muscle waste and the joint stiffen. Movement should be controlled, not avoided.

Do cats really do better than dogs after FHO?

As a rule, yes. Cats are light, agile, and tend to keep the leg moving on their own terms, so they adapt to the false joint quickly and often need only a light rehab plan. Small dogs do nearly as well. The heavier the dog, the more the false joint has to cope with, and the more that muscle and structured rehab matter. That's not a reason to skip rehab for a cat, since some guard the leg and stiffen up, but it does explain why size and weight are such strong predictors of how smooth recovery will be.

How long until my pet is back to normal?

Most pets are bearing weight within a few weeks and moving freely within two to four months, though it varies with size, age, and how much muscle there is to rebuild. The first week is wound healing and comfort. Weeks one to three are about getting the leg moving and taking weight. Weeks three to eight are the muscle-building stretch that shapes the final result. After that, most of the gains are in, and it becomes about keeping the muscle strong. Cats and small dogs often reach the finish line faster than larger dogs.

Is hydrotherapy worth it, or can we manage with home exercises alone?

Home exercises are the foundation, and plenty of small, light pets recover well on them. Hydrotherapy adds something home work can't: the water carries part of your pet's weight, so the leg can move through a full range and start loading well before it could manage that on hard floors. That helps most in the early and middle weeks. The underwater treadmill then retrains a normal walking stride under controlled load. For larger dogs, or any pet that's slow to use the leg, water work often makes the difference between an okay result and a good one.

Sources

  • Off W, Matis U. Excision arthroplasty of the hip joint in dogs and cats. Munich publication reprinted. Vet Comp Orthop Traumatol. 2010;23(5):297-305. PubMed
  • Khazayee et al. The effect of early initiation of physiotherapy on the functional recovery of dogs that underwent femoral head ostectomy. Vet Med Sci. 2025;11(1):e70223. PubMed Central
  • Norberg et al. Factors associated with long-term function in cats treated with femoral head and neck excision. J Small Anim Pract. 2025. Journal of Small Animal Practice
  • Levine D, Millis DL (eds). Canine Rehabilitation and Physical Therapy. 2nd ed. Saunders/Elsevier; 2013.
  • Effective medical management and physiotherapy program of femoral head and neck ostectomy (FHO) in 24 dogs and cats: clinical report. Iran J Vet Surg. 2019. Full text

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