Feline Hip Dysplasia

When you hear people talk about Hip Dysplasia and that radiographs have been taken most people are referring to dogs. But this problem also applies to cats in general. Hip Dysplasia is a hereditary defect in the socket joint (in the pelvis) which means that it is not as deep as it normally should be. Because of this, the ball does not fit exactly in the socket joint and the surfaces begin to rub against each other, causing the cartilage to degenerate. Then the joint surface is made up solely of bone (the cartilage having been worn away) leaving a bone-against-bone joint surface which is painful for the cat. The problem is that the body cannot renew the cartilage, and the body tries to repair the damage by increasing bone production which only serves to make the problem worse. Cats in general are very good at not showing pain and can suffer from HD without limping at all. Instead, they may move more carefully or less than cats normally do, and may also avoid jumping. Cats with a mild degree of HD may not suffer at all.

Since January 2000 the Swedish Maine Coon Cat Club has kept a public register of hip radiographs. This register is since June 2010 administered by PawPeds. The recommendation is that all breeding cats should be tested for HD before being used in a breeding program in order to minimize HD in the breed. The register is official and its purpose is to find the frequency of HD in the Maine Coon breed. The health program collaborated with the veterinary Dr. Lars Audell, who is the leading specialist in this field in Sweden, during the setup and the first 15 years of evaluations. From February 2020 Elisabeth Ball evaluates the radiographs. The evaluated radiographs and the test results are sent to PawPeds. The results will then be available to the public 60 days after the cat owner has received them. The result is sent to the cat owner as soon as PawPeds has received payment.

Other breeds than Maine Coons are also welcome to join in this health program

As Hip Dysplasia is not only found in the Maine Coon breed, it might be of interest to know for other breeds that they also have the possibility to join in this health program. It appears in most breeds to a greater or lesser extent. Once there is a certain number of evaluations available, it will be possible for the breeders of that breed to make more specific recommendations for their breed. The registry for other breeds will be kept by the same person as for the Maine Coons and the procedure is identical for the moment.

 nanzi hoft  hdhoft
 Radiograph of a cat with normal hips  Radiograph of a cat with HD, degree 3, in both hips


Results and statistics from the health program are sometimes published. Here are some examples of the registry (2018):

Offsprings HD-status (worst hip) based on parents status (worst hip). Total number of evaluated cats: 4263
               ¦ N x N   ¦ N x 1   ¦¦ 1 x 1   ¦ 2 x 2   ¦ U x U   ¦
               ¦ (n=949) ¦ (n=505) ¦¦ (n=57)  ¦ (n=4)   ¦ (n=1662)¦
¦ Normal (N):  ¦ 76.7%   ¦ 62.2%   ¦¦ 50.9%   ¦ 25.0%   ¦ 57.8%   ¦
¦ Grade 1 (1): ¦ 14.1%   ¦ 24.8%   ¦¦ 24.6%   ¦ 50.5%   ¦ 21.1%   ¦
¦ Grade 2 (2): ¦  5.4%   ¦  8.9%   ¦¦ 15.8%   ¦ 25.0%   ¦ 13.3%   ¦
¦ Grade 3 (3): ¦  1.9%   ¦  1.6%   ¦¦  1.8%   ¦   ---   ¦ 5.4%    ¦

               ¦ N x N   ¦ N x 1   ¦¦ N x 2   ¦ N x 3   ¦ 
               ¦ (n=949) ¦ (n=505) ¦¦ (n=68)  ¦ (n=18)  ¦
¦ Normal (N):  ¦ 76.7%   ¦ 62.2%   ¦¦ 55.9%   ¦ 50.0%   ¦
¦ Grade 1 (1): ¦ 14.1%   ¦ 24.8%   ¦¦ 17.6%   ¦ 16.7%   ¦
¦ Grade 2 (2): ¦  5.4%   ¦  8.9%   ¦¦ 13.2%   ¦  5.6%   ¦
¦ Grade 3 (3): ¦  1.9%   ¦  1.6%   ¦¦  2.9%   ¦  5.6%   ¦

PP HD tall2018

The number of HD tested cats and available results indicate that the development certainly looks promising. The statistics show very clearly that parents with a normal hip status (N) in general produce offspring with better results than parents whose hip status is unknown (U).

scientific study of the HD results in the health program was published in 2019. There you will find a more thorough analysis of the statistics and the results of the health program.

Hip Radiographs

Information to the Cat Owner

Information to the Veterinary


Clubs presently participating in this health program:

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