ROTT N CHATTER, August 1992, Volume 1 Number 1


 
CANINE HIP DYSPLASIA
by Dr. Gaea Mitchell, DVM Canine Hip Dysplasia (CHD) is one of the best known and most dreaded problems of concern to owners of Rottweilers and many other breeds. Its symptoms may be seen in pups as young as 5 months, or remain unrecognized until a dog's final years. The severity can vary from a mild stiffness on rising to total crippling of a young dog. CHD is a polygenic trait (influenced by several genes rather than just one) which is heritable, but the severity of the condition is affected by environmental factors. While there is no way to change the genetic "program" that determines normal or dysplastic hips, the severity of symptoms can be minimized by controlling the puppy's weight and activity level and to subject the developing joints to the least trauma possible. Many theories abound, one of the most likely being that the femoral head and its support structures (teres ligament, joint capsule and muscles) are faulty and so the hip socket, or acetabulum, does not develop normally in response to early weight bearing on the joint as the puppy begins to walk. It is then possible for the joint to subluxate, or partially dislocate, rather than to glide smoothly in the normal ball and socket fashion. As the joint moves there is abnormal wear and erosion of the joint cartilage, thickening of the joint capsule and production of new bone in the acetabulum remains shallow and the femoral head may flatten. The dorsal rim of the acetabulum, which should cup over the femoral head and help retain the head in the socket, erode and become worn down. These are the events that result in degenerative joint disease (DJD) and cause the pain and loss of joint function seen as the condition progresses. Early signs of CHD include difficulty in rising, or stiffness on rising, but this may correct itself as soon as the dog begins to move and "warm up". Later in the course of the disease the dog may always exhibit some pain, and begin to loose some strength in the rear quarters. Radiographic evaluation will indicate the degree of bony change, but cannot show soft tissue changes or the degree of pain perceived by the dog. The Orthopedic Foundation for Animals (OFA) uses certain criteria to evaluate hip joints, based on films taken in the proper position. The pelvis must lie flat on the table, with good symmetry, the femurs pulled straight back and rotated so that the patellae (kneecaps) lie above the stifle joint (knee). Only films with proper positioning will be read. Both hips should have deep acetabulae with the well rounded femoral head seated deeply and the anterior acetabulum paralleling the femoral head. There should be no sign of roughness, or osteophyte formation on the pelvis, in front of the acetabulum or along the femoral neck. For those dogs affected with CHD there are a variety of treatments which can be tailored to the individual need. Many mild cases respond to building up the muscles that support the hip joint, and use of the non-steroidal anti-inflammatory medications as needed. This may be simple aspirin, a combination of aspirin and a low dose of steroid or Butezolidin. (Ibuprofen is generally NOT recommended in dogs, as it has an adverse effect on the liver.) There have been reports of successfully maintaining dysplastic dogs on food supplements such as vitamin C, MSM, Glycoflex etc. While I am not discounting these as helpful, there is a shortage of clinical study data to support the results of their use. I would recommend that anyone who wants to try products do so with an open mind, but be ready to proceed with more traditional treatment plans as needed. NEXT MONTH A SYNOPSIS ON SURGICAL PROCEDURES