Legg-Perthes in dogs


  • Legg-Perthes is a painful condition that causes the hip joint to crumble and collapse.
  • Legg-Perthes affects young dogs and is most common in small breeds.
  • Legg-Perthes can be treated with an operation to remove the diseased hip joint.
  • With successful treatment, the outlook for a dog with Legg-Perthes is good.
  • Dogs that have had Legg-Perthes shouldn’t be bred from, because the condition can be passed on to the puppies.

What is Legg-Perthes Disease?

Legg-Perthes is a painful condition that affects the hip. Poor blood supply to the ‘ball’ part of the hip joint causes the bone to die and crumble. This leads to a stiff, painful hip joint which causes a limp, and eventually arthritis.

Legg-Perthes often develops at around five months old and most commonly affects small breed dogs. Legg-Perthes usually only affects one hip; it is rare for both to be affected.

Illustration showing Legge-Perthes vs healthy hip

Legg-Perthes causes the hip joint to crumble and collapse. Click image to enlarge.


Symptoms of Legg-Perthes usually start at around 5 months of age and often include:

  • Limping and stiffness in one back leg
  • Shrinking leg muscles (because the leg isn’t being used properly)
  • Progressively worsening pain.

When to contact your vet

Contact your vet if you are concerned your dog may have Legg-Perthes, or if they have developed a limp.


Your vet will examine your dog’s back legs and hips. If they suspect Legg-Perthes, they will need to take an X-ray of the hips.


Anti-inflammatory pain relief

Anti-inflammatory medicines don’t fix the problem, but will be given throughout treatment to reduce pain and inflammation.


Your vet is likely to suggest an operation called a ‘FHNE’. FHNE surgery involves removing the damaged section of hip-bone. After it’s been removed, fibrous tissue fills the space and forms a ‘false’ joint. A false joint isn’t as flexible as a normal hip joint, but allows your dog to walk pain free.


Physiotherapy will be necessary for a few weeks after surgery to help your dog start using their leg again.

Hip replacement

A hip replacement is an alternative treatment option for Legg-Perthes, but is often only recommended for large breed dogs that don’t do so well with FHNE surgery. Small dogs tend to do very well with FHNE surgery. Hip replacements are usually performed by specialist vets in referral practices.


With proper treatment including surgery, pain relief and physiotherapy it’s likely that your dog will respond and recover well. Once their surgical wound has healed and their false hip has formed, they should be able to walk without pain. Some dogs continue to limp once they have recovered (because of the false hip joint, not pain) but many dogs recover so well that it can be difficult to tell that they ever had a problem.

Without any treatment, your dog will suffer with a painful hip and arthritis.


After surgery, you will need to help your dog recover. This will include medication and strict rest for a few weeks, followed by controlled exercise to make sure their false joint forms properly and becomes as flexible as possible.


We shouldn’t breed from dogs that have suffered from Legg-Perthes because it can be passed on to their puppies.


Treatment for Legg-Perthes can become very expensive.

Don't overlook the importance of dog insurance. You should do this as soon as you welcome your new companion into your home, even before any signs of illness become apparent. By doing so, you can ensure that you have the full financial backing required to adequately care for your beloved pet.

It’s also very important to speak openly to your vet about your finances, the cost of treatment, as well as what you think is right for your dog. There are often several treatment options so if one doesn’t work for you and your pet then the vet may be able to offer another.

Published: September 2019

Written by vets and vet nurses. This advice is for UK pets only. Illustrations by Samantha Elmhurst.