This is an autosomal recessive condition that affects Labradors, as well as several other related breeds.

The condition is also seen in mixed breeds, mainly Labrador crosses.

The condition is not common, although it is estimated up to 35% of the Labrador population (in the USA) may be carriers of the gene mutation that causes the disease (ie mutation of the dynamin-1 gene).

Signs are usually first seen in young adults, between 6 months and 3 years of age.

With vigorous exercise lasting 5-20 minutes, a loss of control becomes apparent in the hind limbs.

Starting as a wobbly gait, the loss of control progresses to collapse, and sometimes dogs may seem confused.

Occasional deaths have been reported, so it is important that exercise is stopped as soon as signs first appear.

Excitement and high temperatures and/or humidity may exacerbate signs.

There are sporadic reports of various supplements having some positive effect in a small number of dogs, as well as one report of sub-anticonvulsant doses of phenobarbitone being useful in some severely affected dogs; however there is currently no proven reliable cure or treatment for this disease.

All affected animals should be withdrawn from work and should avoid situations involving excitement and/or stress.