Image from http://www.australiancattledogsinfo.com/
People are quick to assume hip dysplasia is a condition of large breed dogs. When considering a Pyrenees, we are asked about disease conditions they are prone to, and we often hear a "Hip Dysplasia, right?" comment. What is hip dysplasia and who monitors it's frequency?
My resource suggests it's uncommon in dogs under 25 pounds, but it is still one of the most prevalent hip disorders, and one doesn't necessarily think of 40 pound dogs when they consider it.
While the disease is complex, some contributing factors are genetics, environmental and dietary factors, disparity between muscle mass and the developing skeletal system, or the failure of soft tissues of the hip to maintain joint congruity between the surfaces of the hip joint, resulting in bony changes within the joint. (factors sited from "Common Diseases of Companion Animals", Alleice Summers)
There are 2 kinds of dysplasia, Acetabular or Femoral. The acetabulum is the "socket" the head of their femur (the big leg bone) sits in. The femoral head, naturally, is then the head of the femur which sits into the acetabulum. Either the femoral neck is shortened, thusly not fitting into it's socket well, or the socket itself can be malformed, prohibiting the head of their femur from fitting correctly (this is the most common).
This disease condition can impact dogs of any age, though we tend to think of it as something that hits our dogs when they are older. We are all familiar with the signs: difficulty standing, stiffness, pain, reluctancy to move.
There are many categories of the severity, and it's a scary enough condition that we can often find ourselves avoiding dogs we perceive to be at risk. The OFA, "The Orthopedic Foundation For Animals" is the organization most widely trusted to monitor and evaluate this condition. Before breeding, you acquire a rating from the OFA to ensure your puppies will be less prone, as their mom and dad achieve good scores. Owners achieve this certification by getting and submitting pelvic radiographs.
Now on to Pyrs.. The OFA publishes results of their findings, and you may be surprised to realize where Pyrs fall. They ranked 102nd out of 160 evaluated dogs between January, 1974 and December, 2010. The top 5 breeds were ( in order of most to least) Bulldog, Pug, Dogue de Bordeaux, Otterhound, and Neopolitan Mastiff.
True, only dogs evaluated by the OFA are reflected in these results, but I still think it's an interesting starting point for owners, considering Pyrs, who are concerned about the condition.
Image from http://www.whiteshepherdsaustralia.com/