Congenital myasthenic syndrome (Old Danish Pointer type) is an inherited Neuromuscular Disease affecting Old Danish Pointers. Clinical signs of exercise intolerance are noted in affected dogs between 12-16 weeks of age. Affected dogs can exercise and run normally for periods of 5 to 30 minutes. However, if exercising for longer periods of time, affected dogs will start running with progressively shorter strides until they eventually collapse. Dogs are able to recover from the transient paralysis after a few minutes of rest but if exercise is started again, symptoms will recur. The disease does not appear to progress in severity in affected dogs.