Congenital Myasthenic Syndrome in Dogs

Category: Nervous System & Behavioral
Breeds documented: 2
Published sources: 7

Overview

Inherited faults in communication between nerves and muscles can leave a puppy weak and easily tired. This group of disorders affects the junctions where nerve signals reach muscle fibers. Several genetic forms are known, and the weakness often becomes more obvious during activity. Some affected puppies repeatedly sit or lie down because they cannot keep walking normally.

Signs to watch for

Tiring quickly during activity
Short, stiff steps that worsen with continued walking
Repeatedly sitting or lying down during a walk
Food coming back up without retching in some affected puppies

Signs commonly begin during the first weeks or months of life.

Emergency Go to an emergency vet now if your dog struggles to breathe.

Diagnosis and tests

A vet may use electrical testing to assess how well nerves activate muscles during repeated stimulation. Blood tests can help separate inherited syndromes from autoimmune myasthenia gravis, an illness in which the immune system attacks nerve-to-muscle connections. DNA tests are available for several known genetic forms, including the forms reported in Labrador and Golden Retrievers.

Breeds with documented risk

2 breeds

By breed size

2 Large

Labrador RetrieverLarge · Sporting Group
Golden RetrieverLarge · Sporting Group

Inheritance

Not yet known
None of the sources we use states how this is inherited in dogs yet.

We've gathered what published sources say about this condition, so you can talk it through with your vet. It isn't veterinary advice: you and your vet know your dog best.