Congenital Myasthenic Syndrome (CMS) is an inherited neuromuscular disorder characterised by muscle weakness, exercise intolerance and collapse.
In affected dogs, initial symptoms can be seen around the age of 12-16 weeks.
Affected dogs can exercise normally for periods 5-30 minutes, after that they start running with increasingly shorter strides until they eventually collapse. Affected dogs will recover after few minutes of rest but if they exercise again, symptoms will recur.