Dear Daisy Dog
When he plays hard, Jake, my 3-year-old Labrador, gets wobbly and sometimes falls over. The veterinarian diagnosed exercise-induced collapse and said the only way to prevent the problem is not to let Jake romp so hard or get too excited. What else can you suggest?
Labrador retrievers are the most popular purebred dog in the United States. Sadly, some of them have a mutated version of the dynamin 1 (DNM1) gene that causes exercise-induced collapse (EIC).
Your veterinarian is right that EIC can be prevented only by avoiding intense exercise and excitement.
While only three to five percent of Labradors are affected, 30 to 40 percent are carriers, which means they can pass the mutated gene to their offspring. The mutation is equally common in all Labradors, whether they are pets, show dogs or hunting dogs.
Labradors with EIC are normal at rest. Even mild to moderate exercise causes no problems.
However, five to 20 minutes of strenuous exertion coupled with excitement may cause loss of coordination, hind leg weakness and, sometimes, collapse. Hyperventilation and fever accompany the episodes.
Most dogs recover 10 to 25 minutes after exercise stops. Death is rare.
EIC also strikes Chesapeake Bay retrievers and curly-coated retrievers.
Genetic testing is available through the University of Minnesota Veterinary Diagnostic Laboratory (www.cvm.umn.edu/vdl/ourservices/canineneuromuscular/home.html).