What is the immune system? What implications do autoimmune diseases have for the breeder? The term «Autoimmune disease» is currently making the rounds among dog breeders and exhibitors and in the veterinary community. Diseases caused by a defective immune system are of particular rheumatoid arthritis is a complicated and usually progressive disease among many purebred fanciers.
I have not used this acronym. The immune system is a marvelous defense network of white blood cells, antibodies, and other substances used to fight off infections and reject foreign proteins. It is a police force patrolling the body, designed to recognize «self» cells from «non-self» cells by markers found on the surface of every cell in the body. It is this ability that causes the body to reject skin grafts, blood transfusions, and organ transplants. Like anything else, the immune system can fail, either by not doing its job or by doing it too well.
Remember the «boy in the bubble? In all these diseases, the defective immune system fails to protect the body, leaving it vulnerable and open to attack by an opportunistic infection. Autoimmune disease, on the other hand, is a different kind of immune system failure. In this situation, the ability of the immune system to recognize the «self» marker is lost, and it begins to attack and reject the body’s own tissue as foreign.
One specific tissue type such as red blood cells may be affected, or a generalized illness such as systemic lupus may result. What causes the immune system to short circuit and start rejecting normal body tissue? Many theories exist, but the ultimate answer is «We don’t know. Jean Dodds, a veterinarian studying immunology, feels that multivalent modified-live vaccines overstimulate the immune system.
Others blame environmental pollutants or food preservatives such as ethoxyquin, an antioxidant found in most dog foods. There is strong evidence for a genetic factor in the development of autoimmune disease in many species. And some cases occur spontaneously, causing damage to kidneys, lungs, or thyroid gland. The most obvious is that affected dogs may be very ill or even die, a devastating loss when your champion bitch or premier stud is affected.
Secondly, most autoimmune diseases are treated with very high doses of corticosteroids or other immunosuppressive drugs to lower the immune response, much like a kidney transplant patient takes anti-rejection drugs. Steroids suppress a bitch’s heat cycle, sometimes rendering her incapable of breeding. If she should become pregnant, the daily medications she takes will cause birth defects in the puppies, including cleft palates and malformed limbs, and produce premature labor or spontaneous abortions. Because of the strong suspicions for genetic transmission of these diseases and potential risks to the bitch and the litter, affected dogs should not be bred. What about breeding close relatives—littermates, sire, dam, half-siblings— of affected dogs? Should a breeding that has produced one or more affected dogs be repeated?