Exercise induced collapse syndrome in Labradors & Collies

Exercise induced collapse (EIC) syndrome is a condition that has become recognised since the mid-1990s. There has been some published work in the USA in Labrador Retrievers (Shelton & Taylor 2002), but we also recognise the same condition in Border Collies in the UK.

EIC syndrome is primarily seen in athletically fit young Labradors or Collies less than 3 years of age. It seems that many affected dogs have a very excitable and active nature. EIC appears to be more prevalent during the warmer summer months, but can also occur in dogs swimming (strenuous exercise) in cold water.

Description of the collapse
Most dogs can tolerate routine exercise, but after a short period (10 - 15 minutes) of strenuous or extreme exertion such as repeatedly chasing a ball they develop weakness and exhaustion leading to recumbency and excessive panting. Rectal temperature may reach 41.4oC (107oF), although one study suggests this is the case in normal dogs anyway (Shelton & Taylor 2002). There is sometimes loss of patella reflexes and poor conscious proprioception. If the dog is made to walk, there is usually incoordination, particularly of the hind legs, or loss of balance. The dogs normally remain bright, alert and responsive. They may seek a cooler place to lie, such as shade, or have a drink of water. The syndrome develops over a period of a few to several months, and in some ways, it is as if there is ‘a loss of fitness’. Recovery after an episode of collapse may take 5 to 20 minutes.

Prognosis
In most dogs this does not appear to be a progressive disease and simply a recognition of the problem and a restriction of such strenuous exercise is sufficient for dogs to maintain an otherwise normal quality of life. There have been a few reports of death in the USA in very severely affected dogs, but we are not aware of such severe cases in the UK.

Research
A lot of work has been undertaken (Shelton & Taylor 2002) and this has ruled out hypoglycaemia, electrolyte imbalances, hypothyroidism, Addison’s disease and myasthenia gravis. Muscle biopsies have been non-specific. There is some evidence that there is an abnormality in pyruvate and carnitine metabolism, studies are ongoing.

For more information see the following link:
http://medicine.ucsd.edu/vet_neuromuscular/cases/2002/may02.html

Treatment
Because the cause of this syndrome is unknown, there is currently no known treatment. It is suspected that the condition may be some form of metabolic myopathy and thus empirical treatment for that is worth trying. In addition to restriction in exercise the following may be beneficial:

• L-carnitine at 50mg/kg twice a day
• CoEnzyme Q10 at 100mg per dog each day
• Riboflavin (vitamin B2) at 100mg per dog each day

References
Shelton GD & Taylor SM (2002) The syndrome of exercise induced collapse in Labrador retrievers. Proc. 20th ACVI