Exercise Induced Collapse (EIC)
EIC is a nervous system disorder that is inherited in Labrador retrievers, Curly coated retrievers,
Chesapeake Bay Retrievers, German Wirehaired Pointers, Cocker Spaniels, Boykin Spaniels,
Bouvier des Flanders, Old English Sheepdogs and Pembroke Welsh Corgis. It is inherited as an
autosomal recessive trait, meaning that the causative mutation must be inherited from both
parents in order to produce an affected puppy. Carriers of EIC appear normal and have normal
exercise tolerance, but they will pass the causative genetic mutation on to half of their puppies.
Dogs affected by EIC are perfectly normal most of the time and it is impossible for an owner or a
veterinarian to determine that there is anything wrong with them. They may, however, experience
episodes of collapse when they participate in strenuous activities that they find exciting or
stressful, especially in warm weather. During a collapse episode, the rear limbs typically become
weak and unable to support weight. The dog's gait will become incoordinated and they may
actually collapse and be unable to move. Most dogs recover quickly and are not stiff or sore but a
few dogs have died. Dogs symptomatic for EIC are rarely able to continue training or competition
but they can live normal lives if participation in the types of activities that induce their collapse
episodes can be avoided.
Research to investigate and characterize EIC in Labrador retrievers has been led during the last
decade by a team at the WCVM (Drs. Taylor and Shmon). They collaborated with a team of
veterinarians and geneticists at the University of Minnesota (Patterson, Mickelson, Minor) and in
2007 the genetic mutation causing EIC was identified and a test for the causative mutation was
made available through the Veterinary Diagnostic Laboratory at the University of Minnesota.
DNA testing can confirm that a collapsing dog has EIC.
More importantly, testing can be used to determine whether a dog that will be used for breeding is
affected by EIC (has 2 copies of the causative mutation E/E), is a carrier of EIC (has one copy of
the causative mutation E/N), or is clear of EIC (no copies of the mutation N/N). This is important
information to have about a dog prior to breeding so that a breeder can avoid producing dogs
affected by EIC.
- If an affected dog is bred to another affected dog all offspring will be affected
- If an affected dog is bred to a carrier dog, 50% of offspring will be affected and 50% will be carriers
- If an affected dog is bred to a clear dog, all the offspring will be carriers
- If a carrier is bred to a carrier, approximately 25% of the puppies will be clear of the mutation, 50% will be
carriers and 25% will be affected by EIC.
- If a carrier is bred to a non-carrier, none of their pups will be affected, but 50% will be carriers.
Note that not all dogs affected by EIC (2 copies of the mutation) will have had episodes of
collapse. Approximately 85% of affected dogs have collapse observed by the time they are 3
years of age, but some affected dogs never exercise with the intensity and excitement required to
induce an episode of collapse. Without genetic testing it is impossible to say for certain that a dog
is not affected by EIC.
The EIC mutation is common in populations of the susceptible breeds.
In the populations of dogs tested
5-15% of Labrador retrievers have been affected, and 35-40% have been carriers
2-3% of Chesapeake Bay retrievers have been affected, and 15-20% have been carriers
15-20% of Curly Coated Retrievers have been affected and 30-35% have been carriers
Testing for EIC involves the collection and submission to the laboratory in Minnesota of an oral
swab for DNA. This should be done by a veterinarian. The veterinarian will also verify the
identity of the dog being tested (microchip or tattoo) for the laboratory. All results are eligible for
posting on the Orthopedic Foundation for Animals (OFA) website for a nominal charge with owner
consent. For more information about EIC and the test see the website:
http://www.cvm.umn.edu/vdl/ourservices/canineneuromuscular/home.html
Owners who would like to have their dog tested for EIC at the WCVM should do
the following:
(1) Make an appointment with the Small Animal Medicine service for DNA testing.
(2) Go to the EIC website
http://www.cvm.umn.edu/vdl/ourservices/canineneuromuscular/home.html
Click on the submission form option, fill out the form online and print it to bring with them to
their appointment. Filling out the form online minimizes the chance that there will be
typographical errors in your dog's information when we submit a handwritten form to the
laboratory with the sample.
(3) You must pay the Minnesota laboratory directly for the testing (not the WCVM). If you
wish to pay for the test by credit card fill out the credit card authorization form that is
attached to the submission form and bring that with you to the appointment.
If you do not wish to pay by MasterCard or Visa, you will need to bring a money order or
certified cheque for $65.00 US. (made out to the Veterinary Diagnostic Laboratory,
University of Minnesota) to the appointment so that we can enclose it in the sealed envelope
with the sample.
(4) Do not give your dog anything to eat or drink (except water) for 4 hours before your
appointment.
(5) During the appointment:
- A veterinarian will collect a history and examine your dog. If your dog is due for routine
procedures such as annual examination or vaccination these can be completed during
the same visit.
- Your dog's permanent identity will be verified (microchip or tattoo) if possible. If your
dog has a tattoo please bring a copy of their CKC or AKC registration papers stating the
tattoo number for your dog in case one of the letters/numbers is difficult to read.
-We will perform the DNA swabs, fill out the required forms and seal the samples in
envelopes according to directions from the laboratory
(6) We will give you the samples in a sealed, pre-addressed envelope to mail to the
laboratory. We recommend mailing the EIC test via ExpressPost (Canada Post) to the
Minnesota laboratory.
(7) The VTH fee will be the fee for an office call plus a $35.00 DNA collection and
processing fee (includes the swabs).