If you thought only old, arthritic dogs got wobbly in the back end, think again. Hip dysplasia is an inherited disease that can cause lameness in puppies less than 1 year of age in severe cases. Milder cases may show lameness later, and signs worsen with age. Is your dog at risk?
What is hip dysplasia?
Hip dysplasia refers to abnormal development of the hip joint. It is a genetic disease (inherited) but is also influenced by other factors, especially diet. Hip dysplasia causes lameness due to joint pain, which progresses with age as the changes in the joint worsen (Degenerative Joint Disease).
Large and giant breeds of dogs are more frequently affected, especially German Shepherds, Labradors, Retrievers, and Rottweilers.
What are the signs of hip dysplasia?
Puppies less than 1 year of age will exhibit lameness, a reluctance to jump up or climb, a reduced exercise tolerance, and sometimes a ‘bunny hopping’ gait (both hind legs used together).
In milder cases, signs may only appear later due to secondary joint changes, or Degenerative Joint Disease. In these cases, pain and lameness are due to erosion of the joint cartilage, narrowing of the joint space, hip remodelling and new bone formation.
What are the causes of hip dysplasia?
It is an inherited disease but is also influenced by diet and rate of growth, and excessive exercise at an early age. It is also possible that other developmental diseases are present. Specialised premium dog foods are available for large breed puppies to limit their rate of growth.
How is hip dysplasia diagnosed?
The history of a large or giant breed puppy with typical signs is suggestive of hip dysplasia. They may have well-muscled front quarters due to reluctance to use the hindquarters. A physical examination is performed, and then X-rays under general anaesthesia. Characteristic signs are seen on X-ray, and the hips are also manipulated under anaesthesia to assess the amount of joint laxity.
How is hip dysplasia treated?
Treatment involves surgery or conservative measures.
Surgery includes T.P.O., hip replacement, excision of the hip, and sometimes cutting of a hip muscle (pectineal myectomy):
- T.P.O. refers to Triple Pelvic Osteotomy and is used in puppies younger than 11 months with little or no signs of arthritis. The aim of surgery is to improve the congruency (fit) of the joint so that the development of future arthritis or Degenerative Joint Disease is minimised. The surgery has a very good success rate but individual cases must be assessed by a surgical specialist to see if they are candidates for T.P.O.
- Hip replacement is used for older dogs with arthritis. Again, individual cases are examined by the surgery specialist to assess their suitability for the operation. This operation also has a very high success rate. In smaller dogs (usually less than 15kg weight) the hip may be able to be removed, thus removing the source of pain.
Conservative treatment of the young dog includes slowing the growth rate of the puppy and keeping him at his ideal bodyweight. Exercise is modified to consist of frequent short walks or swims, and avoiding off-leash free running. Anti-inflammatory and analgesic drugs may be prescribed.
Conservative treatment of older dogs includes weight and exercise management and the use of drugs. Apart from anti-inflammatory and analgesic drugs, another group of drugs includes chondroprotective agents. These aid the cartilage repair process and reduce cartilage breakdown and often involve a course of injections over 4 weeks, supplemented with a daily capsule, tablet or gel.
What is hip scoring?
Some dog breed societies have a hip-scoring scheme to try to reduce the incidence of hip dysplasia by not using affected dogs for breeding. If you are considering obtaining a puppy of an at-risk breed, reputable breeders will have the hip scores of the parents of the puppy available for your examination. You can contact breed societies or your veterinarian for more information on the scheme.