Selecting Against Canine Hip Arthritis - Penn Hip
By Neil Stuttle
Arthritis is one of the most common conditions we see in a variety of dog breeds and results in pain, loss of athletic ability, and worst case scenario euthanasia. Hip arthritis is common and can affect both young and old dogs. The primary cause of hip arthritis is excessive hip laxity otherwise known as hip dysplasia.
In severe cases hip laxity will cause obvious pain/discomfort in the first 6 -12 months and is simple to diagnose on standard hip x-rays. Mild/moderate degrees of hip laxity will cause arthritis to develop over longer periods of time. A frustrating situation we commonly see is a 2 -4 year old dog become crippled with hip arthritis for which there is essentially no cure. In the past under the old NZVA hip dysplasia scheme it has been difficult to identify these dogs when they are young for 2 reasons. 1) The requirement for dogs to be at least 12 months old and 2) The scheme screens for the secondary changes of hip arthritis and conformational change not hip laxity which is the primary factor leading to arthritis. Thus a dog with excessive hip laxity but a slow development of arthritis would have a good score but still go on to develop arthritis. Some studies estimate this situation can happen in 80% of dogs with good scores!
The introduction of Penn Hip distraction x-rays enables hip laxity to be directly measured from 4 months of age. The higher the degree of hip laxity, the greater risk of arthritis. Penn Hip results are reported as a distraction index and recorded on a world wide data base, thus results can be compared with breed averages. The Penn Hip result gives a quantitative risk of an individual dog developing hip arthritis and also a comparison of hip laxity compared to the breed average. This comparison is useful for breeding purposes. When hip dysplasia is diagnosed early medication, exercise/ dietary management and surgical procedures are available to minimise the progression of arthritis.
Hip dysplasia/arthritis is one of the major genetic conditions affecting NZ dogs. Penn Hip provides an exciting new approach in screening for this debilitating disease. Vet Services Hawkes’ Bay encourages Penn Hip testing in young dogs from 4 months of age. If you are interested in having your dogs hips assessed please call one of our clinics to find out more.