Exercise-Induced Collapse

Exercise-induced collapse (EIC) in dogs is a genetic disease that affects certain breeds, such as Labrador Retrievers, Boykin Spaniels and Chesapeake Bay Retrievers. EIC is characterized by episodes of hind limb incoordination and non-painful muscle weakness that may progress to collapse and are triggered during or immediately after periods of intense exercise or excitement.

Symptoms

Symptoms of CIE can vary in severity from mild weakness to total collapse and loss of consciousness. Symptoms usually appear within 5 to 15 minutes after intense exercise, and can last up to 30 minutes. Dogs begin to stagger and lose control of the hind limbs. They may also experience tremors, panting and difficulty breathing.

Disease Management

Dogs with IBD should avoid intense or prolonged exercise and be closely monitored during periods of activity. If you suspect your dog may have EIC, it is important to see your veterinarian for a proper diagnosis and the best treatment options for your dog's specific needs.

Genetic basis

This disease follows an autosomal recessive mode of inheritance. Autosomal recessive inheritance means that the dog, regardless of sex, must receive two copies of the mutation or pathogenic variant to be at risk of developing the disease. Both parents of an affected dog must carry at least one copy of the mutation. Animals with only one copy of the mutation are not at increased risk of developing the disease, but may pass the mutation on to future generations. Breeding between dogs carrying genetic variants that can cause disease, even if they do not show symptoms, is not recommended.

Technical report

The exact cause of CID is not yet known, but it is thought to be due to a mutation in the DNM1 gene coding for the enzyme dynamin 1 which is expressed in the brain and spinal cord and is involved in the regulation of synaptic transmission at rest and during moderate exercise. The c.767G>T mutation, identified by Patterson et al. in 2008 in families of Labrador Retriever dogs, affects the muscle's ability to relax and can lead to impairment of normal muscle function, interfering with the transmission of nerve signals, especially during periods of increased physical exertion.

Most affected breeds

Border Collie
Boykin Spaniel
Chesapeake Bay Retriever
Curly-coated retriever
Labrador Retriever

Bibliography

Ekenstedt KJ, Minor KM, Rendahl AK,et al. DNM1 mutation status, sex, and sterilization status of a cohort of Labrador retrievers with and without cranial cruciate ligament rupture. Canine Genet Epidemiol. 2017 Feb 2;4:2.

Minor KM, Patterson EE, Keating MK,et al. Presence and impact of the exercise-induced collapse associated DNM1 mutation in Labrador retrievers and other breeds. Vet J. 2011 Aug;189(2):214-9.

Patterson EE, Minor KM, Tchernatynskaia AV,et al. A canine DNM1 mutation is highly associated with the syndrome of exercise-induced collapse. Nat Genet. 2008 Oct;40(10):1235-9.