Acquired Myathenia Gravis

Acquired MG is an autoimmune disease in which the body's immune system mistakenly attacks and destroys special proteins (acetylcholine receptors) located on the muscle surface where the nerve attaches to the muscle.

Muscle weakness is the distinctive feature of MG. The muscles affected are voluntary or striated muscles and different muscle groups can affect different dogs, making clinical signs different as well and diagnosis of MG can be difficult. A common sign is regurgitation. Excessive salivation as well as multiple attempts at swallowing food may be another signal. A high-pitch bark or no bark may also be another sign as well as the dog appearing to sleep with his eyes open as the eyelid muscles may be too weak.

A very severe form of MG has also been described in which there is a rapid onset of muscle weakness involving esophagus and respiratory muscles. Treatment requires intensive care including ventilatory support.

Additional information:

Note: This section of the Canada's Guide to Dogs website is intended as a source of information only. It is not intended as a substitute for professional care. Always consult with your Veterinarian about health related matters.