Myasthenia Gravis in Dogs: Symptoms, Diagnosis & Treatment

Myasthenia Gravis in Dogs: Symptoms, Diagnosis & Treatment

Author WDF Staff


Most dog owners never thought about dealing with health issues when they imagined what it would be like to get a dog. Most of us imagine only the fun parts of owning a dog, like walks, hiking or playing. However, dogs can develop all sorts of conditions and diseases. One of them is called myasthenia gravis. This weird-sounding condition can be pretty worrying. Here’s what you should know about myasthenia gravis in dogs.

What is myasthenia gravis in dogs?

Myasthenia gravis is a disorder in which the passage of signals between the nerves and muscles is disrupted. Myasthenia gravis causes significant weakness and exhaustion in dogs. Some breeds are predisposed to a congenital version of this condition. Those breeds are;

sick chihuahua

Like other immune-mediated disorders, acquired myasthenia gravis is a complicated condition involving various components such as environmental, viral, and hormonal impacts. Acquired myasthenia gravis is more common in;

A possible complication of myasthenia gravis is thymoma. A thymoma is a tumor mass in the chest cavity that develops in certain dogs with myasthenia gravis.

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Puppies with congenital myasthenia gravis are usually diagnosed between 6 and 8 weeks. Acquired myasthenia gravis is most commonly diagnosed in dogs from two age groups; 1 - 4 years and 9 - 13 years. The majority of cases are acquired rather than inherited.

What are the symptoms of myasthenia gravis in dogs?

The megaesophagus is a dilatation of the esophagus that retains food rather than allowing it to flow into the stomach. Many dogs with acquired myasthenia gravis develop that condition. This causes the food to return through the dogs' lips without the retching and abdominal muscle contractions that come with vomiting. They may have difficulties eating, have a reduced capacity to blink, and/or collapse suddenly. Other myasthenia gravis symptoms include;

  • Voice changes
  • Weakness and/or collapse as a result of exercise
  • Gradual deterioration
  • Inability to close eyes (even during sleep)
  • Severe drooling
  • Difficulties breathing
  • Cramps with little exertion

senior sick pug

Antibodies to acetylcholine receptors are elevated in the blood and serve as a useful diagnostic and monitoring tool.

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Is it possible to treat myasthenia gravis in dogs?

Some dogs with myasthenia gravis need to be admitted to the hospital for treatment until their medication dose is established. These dogs are given a medicine that suppresses an enzyme in the nervous system called acetylcholinesterase. For the rest of the dog's life, anti-acetylcholinesterase drugs will be required. Some dogs will inhale food, fluid, or vomit due to their impaired swallowing ability, resulting in aspiration pneumonia. Aspiration pneumonia is a dangerous condition that frequently necessitates aggressive critical care, such as oxygen therapy, antibiotics, IV fluid therapy, and supportive care. A feeding tube may be required until the dog's medication levels are regulated, especially if they cannot eat or drink without regurgitation.

Myasthenia gravis ancillary treatment is as crucial as determining the proper pharmaceutical doses. When a thymoma is present, it must be surgically removed. Smaller, more frequent meals of high-quality, high-calorie food are ideal for these dogs. Their food and water dishes should be elevated. For dogs with myasthenia gravis, there is no single "optimal" dietary formulation. It's crucial to figure out what works best for each dog.

Because of their muscle weakness, most dogs with myasthenia gravis will limit their own activities.

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What drugs should dogs with myasthenia gravis take?

At the neuromuscular junction, acetylcholine is a substance that transfers messages between neurons and muscles. Drugs that suppress the enzyme acetylcholinesterase, which breaks down acetylcholine, extend acetylcholine activity in dogs with myasthenia gravis. The medicine of choice is pyridostigmine bromide. For their ability to suppress the immune system, corticosteroids, azathioprine, or mycophenolate may be employed.

yorkie in a box

Do dogs with myasthenia gravis need to be monitored?

Muscle strength improvement is a clear indicator of therapeutic success. In addition, chest radiographs (X-rays) are checked every 4 - 6 weeks to see if the megaesophagus has resolved. Finally, every 8 - 12 weeks, acetylcholine receptor antibody levels are checked, and with remission, they should fall into the normal range.

What is the prognosis for dogs suffering from myasthenia gravis?

If your dog doesn't have severe aspiration pneumonia, throat weakness, or difficulty swallowing, the prognosis is favorable for a full recovery in 6 - 8 months. The prognosis for dogs with thymomas is uncertain unless the lump is entirely excised and clinical symptoms are under control.

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Although myasthenia gravis is curable, most pets may need to be fed and medicated for months. For the rest of the dog's life, anti-acetylcholinesterase medicines and immunosuppressive therapy will very certainly be required. Life quality is often high if the dog enters remission.

World Dog Finder team

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