Hip Dysplasia in dogs is a genetic trait that is cause by environmental factors and breeding conditions. Found in many animals and even some humans, hip dysplasia is an abnormal function of the hip socket, which in it’s most severe form can eventually cause crippling lameness and painful arthritis on the joints.
The effects of hip dysplasia is common across all breeds of dogs, but mostly seen in larger breeds. Among the many conditions and health concerns for dogs, hip dysplasia is one of the most commonly studied and single cause of arthritis in the hips.
Normal Hip Anatomy vs. Hip Dysplasia Anatomy
In the picture to the right you can see a xray of the hips of a dog. The normal anatomy of the hip join, the thigh bone (or root) is connected with the pelvis at the hip joint. The end of the femur head is called the caput, which fits into the area of the socket bone (also called acetabulum). In between these two bones is a layer of cartilage which allows the two bones to move in a joint and socket motion, without hitting bone on bone contact.
In a dog with hip dysplasia, there are two major differences. First, the caput it not as deeply and tightly placed into the socket. This means there is no longer a snug fit or smooth motion when the joints and hips are being used. Instead, the joints and bones are loose. Since the placement isn’t correct, this means the bones are also not smooth, and can sway in a wide variation of motion, also causing extreme wear and tear on the hips and any bone on bone interaction.
Since the body knows there is a problem in the joint area, the body reacts in many different ways. One of the first ways, is that the joint will continually try to repair itself by building new cartilage between the bones. This is usually a slow process, and continues to get scraped away when bone on bone contact happens. This process will continue over the life span of the dog, but may make the situation worse, as the joints will become more damaged and less likely to resist further damage.
Cause and Effects of Hip Dysplasia
As we discussed earlier, and you can see in the xray above, it’s extremely important to have a socket and joint in the right place to allow for smooth body movement without pain. In dogs, when a femur does not fit in place, the result it poorly developed muscles in the pelvic area. The majority of dogs diagnosed with hip dysplasia are larger breed dogs, especially Cocker spaniels and Shetland sheepdogs. Hip dysplasia is not only limited to dogs, but can also be found in cats as well.
Since hip dysplasia isn’t just an structural issue, it actually does effect the life and pain of an animal. To reduce this pain, dogs with hip dysplasia will be less active and sit around more than other dogs. Hip dysplasia attacks the back leg support of the animal, and makes it extremely hard and pain for them to get up, let alone walk. You will find that some dogs seem like they are bunny hopping, such as both of the back legs are moving together, which reduces pain on the dog, but also their effective movement. Many dogs will end up relying on their spine support to compensate for the loss of their hip support.
Hip dysplasia was mainly considered a result of hereditary health, but is now seen s more of an environmental issue. While both play a part in whether a dog will have hip dysplasia, there is not scientific data which states which is more to blame. Hereditary issues are passed down from parents to their pups, while environmental issues would be considered being overweight, possibly having an injury or overexertion on the hip joints at a younger age, among other things.
The effects of hip dysplasia can been seen in a dog by the time they are 18 months old. As the dog ages, their hips usually get worse, and the end result can be anything from mild to severe crippling, or even cause longterm osteoarthritis.
We will soon be featuring more articles on hip dysplasia in dogs in the following articles:
- Symptoms of hip dysplasia
- Treatment of hip dysplasia
