A Positive Outlook for Exercise Induced Collapse (EIC)

[311Hemi]

Here is an article I wrote for our club newsletter. Thought I would post it here since not many people are aware of the disease. There have been some updates since this was written....but not much. A test is now expected to be available this spring.

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A Positive Outlook for Exercise Induced Collapse (EIC) in Labrador Retrievers

By John Z.

For years now there has been as debilitating disease found in Labrador Retrievers called Exercise Induced Collapse (EIC) for which there has been no test and this has left many owners wondering what's wrong with their dogs. Labs affected by EIC can show episodes of collapse when submitted to activities that both excite and exercise the dogs to the point they start to lose control of their legs and then collapse. At the onset of an EIC episode a lab will often times show symptoms of weakness or wobbliness followed by loss of the ability to control the hind legs, and if not stopped from their current activity they can lose control of all four legs and fully collapse. It can take 10-30 min for the dog to regain control once an episode has occurred and the dogs is otherwise unharmed from the event. Rarely, a dog will die during the collapse. Affected dogs are usually described as having an excitable temperament with a lot of drive and are often extremely fit. EIC is often seen in young labs [under two years of age] but has been seen in dogs as old as 10 years of age.

Over the past few years a comprehensive study has been underway involving the Western College of Veterinary Medicine (WCVM) of the University of Saskatchewan, the College of Veterinary Medicine at the University of Minnesota, and the Comparative Neuromuscular Unit at the University of California. The main objectives of the study are to describe the syndrome so it can be recognized, establish an efficient means of diagnosis, and determine the genetic bases for the disease. This study is not focused on providing a cure for the disease so it will not help currently affected dogs other than to identify what may be causing a symptomatic dog to collapse.

Until recently, the only way this disease could be diagnosed was by observing a symptomatic dog and submitting the dog to multiple tests to rule out all other possibilities for the symptoms. This is both very expensive and time consuming. The good news is that the research team carrying out the study on EIC has recently identified a genetic marker that is highly associated with the EIC condition and has developed a test to determine if a dog has this genetic marker. However, at this point they cannot be certain that this gene is the causative EIC mutation. The research supporting this mutation as the cause for EIC and the test for determining EIC status must be reviewed by independent scientists and published in a scientific journal before an official test for EIC can be made available, but preliminary results are very promising.

Ongoing research into EIC supports that this condition is inherited as an autosomal recessive trait, with affected dogs obtaining one copy of the mutated [bad] gene from each parent. The “unofficial test” for the probable causative mutation performed by researchers at the University of MN determines whether a tested dog is a non-carrier [no copies of the mutated gene], a carrier [one copy of the mutated gene], or affected [two copies of the mutated gene]. It is thought that only the "affected" dogs show symptoms of the condition, however it has been noted by the researchers that very rarely a carrier dog may collapse under specific circumstances although no information has been presented of a where this has actually happened. For a dog to be considered "affected" and have two copies of the mutated gene, both parents must be either "carriers" or "affected" themselves.

One point worth noting regarding labs with EIC is that even though a dog is a "carrier" this does NOT mean that this dog cannot be bred. What's important is that a "carrier" is ONLY bred to "non-carriers" resulting in offspring that may be "carriers", but no "affected" pups would be produced. Breeders will need to take the responsibility both to make sure they don't breed "carriers" to "carriers" [or "affected"] and to inform buyer that pups may be "carriers" so caution is taken when any future breeding is being considered. It has been mentioned by the experts [from the CNM HSOforum] that "they do not recommend removing very high quality dogs that are carriers from the gene pool" and go on to say that "in doing so it would/could remove many excellent characteristics that are desirable as well as further narrow the already small gene pool." CNM [Centronuclear Myopathy] is also an autosomal recessive disease that follows the same genetic links between parents and offspring as EIC is thought to have.

Over the past few months the University of Minnesota research team has visited multiple hunt/field trials in the Midwest to gather more DNA samples [at the owners discretion] to help analyze the results of their test. DNA samples were taken from trails in MN, ND, WI, and Canada. Samples have also been collected from Germany, Australia, and New Zealand and the mutated gene was present in all these countries.

The latest information available is that the test is in the works to be patented and the initial paperwork has been submitted, but a provider for the test has not yet been determined. Barring any setbacks, the official test expected to be available to the public in early 2008.

Some additional information provided by a member of the research team:

1) "I have heard of dogs that are EIC affected (confirmed by our mutation test) not collapsing until as late as age 10 (this is rare)."

2) "body temp/air temp are not the cause of EIC, but high heat and humidity can make it more likely to occur."

3) "some dogs are so severely affected, that they collapse even in water, and some dogs have come very close to drowning if they do collapse while swimming."

More specific information regarding Exercise Induced Collapse can be found at: http://www.thelabradorclub.com/library/eicstudy.html

[LABS4ME]

Thanks Hemi!

Very well written and informative article! This helps shed some light to those not already informed of this horrible disorder!

Thanks again for sharing it...

Good Luck!

Ken

[Augusta]

Same here, Thanks Hemi, I have a lab pup and it sure is nice to have this kind of information.