Myasthenia gravis is an autoimmune disease that can be congenital (hereditary), but can also be acquired. It primarily causes episodic muscle weakness.
The acquired form of myasthenia gravis often appears in the first six months after birth. Older animals show changes primarily around the ages 3 and 9. Initial symptoms are inconspicuous and increase little by little. At first light muscle tremors and/or an unsteady gait may be noticeable. Occasionally the eyelids sag, or hang limp. Later on, considerable movement disorders, as well as a sudden collapse of the hind quarters, or paralysis, can occur. This is especially noticeable after previous the animal has undergone previous physical exertion. After resting, symptoms often completely disappear. A common complication is an atony of the esophagus muscles and an abnormal sagging of the organ. Due to these symptoms, the animal has difficulties swallowing and occasionally chokes. This adds an additional health risk: due to problems swallowing, parts of the animal’s food may end up in their respiratory tract and cause pneumonia.
Myasthenia gravis is caused by antibodies (proteins used for defense) that attack the joints between muscles and nerves and successively destroying them. In some cases, these changes can be traced back to a hereditary genetic defect. However, the disease may also occur without a genetic predisposition. The reasons for this have not yet been fully understood.
Symptoms often allow for a tentative diagnosis of myasthenia gravis. Also, it is possible for a blood count to be used to eliminate the possibility of other diseases. In the acquired form of myasthenia gravis, the antibodies that trigger the disease can be detected in the dog’s blood. Also, an injection of a symptom suppressing drug can be used as a diagnostic agent. A sagging of the esophagus, one of the results of myasthenia gravis, can be confirmed with an x-ray. Regarding treatment of the symptoms, movement disorders can be suppressed with an appropriate medication that has to be administered for the rest of the animal’s life. Anti-inflammatory drugs may also have positive effects. In rare cases, spontaneous recoveries are possible. However, a further enlargement of the esophagus has negative effects on the diagnosis.
The potential danger of myathenia gravis can be viewed as relatively low. To eliminate other, more dangerous diseases, you should consult a veterinarian within the next few days.