Dr. Jody Kaufman
How many people remember the Bedlington Terrier? Probably very few under the age of sixty. Bedlingtons were cute, curly-haired white dogs that looked like little lambs and were once one of the most popular breeds in the U.S. Their demise coincided with the appearance of an inherited condition that caused the liver to be unable to eliminate excess copper. Copper is an essential element in the diet, but an overabundance is toxic. The excess copper gets deposited in the liver, causing inflammation, scarring, and eventually liver failure. Unfortunately for the Bedlington Terrier, understanding of the disease and the fact that it was hereditary came a little too late. The gene pool was so contaminated that there were very few individuals left who weren't carriers.
We have recently been made aware of some new conditions that affect Labrador Retrievers. One is termed Exercise Induced Collapse. These individuals are unable to dissipate heat when they exercise vigorously. Consequently their body temperatures can get over 105 degrees. These dogs will get weak, stumbly, and even collapse when their temperature gets too elevated. There is a gene responsible for the condition and a university lab that tests for it. A responsible Lab breeder would be advised to get the screening done to make sure that their dogs are not carriers, just as they screen parents for hip dysplasia.
The other condition that is just being recognized is a form of copper storage disease. Affected dogs are not recognized until middle age or later when the liver is finally failing. While the genetics haven't been worked out, there are a couple of things that we can do to prevent its expression. It's known that there is a strong dietary component and many dog foods have far more copper (2-3 times) than the actual requirement. So dogs that are over-supplemented are more likely to develop the disease. Royal Canin is working on certain breed-specific diets. The one that's being developed for Labs will have just the right amount. Additionally, one of the liver enzymes that is associated with inflammation becomes elevated early (as young as one year of age) in dogs that are storing excess copper. While it's nonspecific, screening on a yearly basis can help detect a potential problem before it becomes life-threatening.
Is there a lesson to be learned? Many diseases are allowed expression through the interaction of genetics and environment. Sometimes new diseases are surfacing; other times it's just that our awareness and understanding have become more refined.