Canine Myasthenia Gravis: What You Should Know

by | Jul 9, 2021 | Dog Health

Myasthenia gravis is a condition that affects dogs and prevents their muscles from contracting. As a result, it hinders your pets from performing daily activities with ease. 

In this article, you’ll learn about myasthenia gravis, its symptoms, how specialists diagnose it, how it affects your pet, and the possible treatment options. By educating yourself, you can manage the condition and help alleviate your pet’s pain and discomfort.

What is myasthenia gravis in dogs?

Myasthenia gravis (MG) describes the common cause of weakness and pain in dogs and cats. Gravis means grave while myasthenia indicates muscle weakness. The condition affects your canine’s muscles and shortens their life expectancy in some severe cases. Hence, it’s important to manage this condition as early as possible.

MG has two types: congenital and acquired. In the first kind, the MG is inborn. Studies show that Jack Russell Terriers, Smooth Fox Terriers, and Springer Spaniels are prone to congenital MG. 

Alternatively, the breeds of dogs more prone to acquired MG Akitas, German Shorthaired Pointers, Golden Retrievers, and German Shepherds. Of the two, the acquired type is more common than the congenital one. 

How does myasthenia gravis affect a dog’s muscles?

Muscles have their own nerves. However, since these nerves are not linked directly, it creates a small gap in the connection between a muscle and a motor nerve. Due to this microscopic gap, signals need to travel as an electrical impulse. Acetylcholine, a chemical neurotransmitter, ensures that the muscles can receive nerve impulses, allowing dogs to perform basic tasks.

Dogs with MG experience a malfunction in signal transmission between nerves and muscles, preventing the muscles from contracting properly. In turn, pets experience weakness, muscle pain, fatigue, and discomfort. In extreme cases, dogs can even experience breathing and eating difficulties.

What are the symptoms of canine myasthenia gravis?

Myasthenia gravis in dogs includes symptoms of exercise-related weakness. However, these symptoms usually go away once your pet gets enough rest. But if you notice cramping or collapsing after a mild exercise, it’s advisable to contact a specialist immediately. Dogs with MG also show signs of progressive weakness. It’s important to manage this condition before it turns serious and affects your pet’s daily life.

MG can also affect other organs. For example, you may notice changes in the way your pet barks due to vocal fatigue. Some dogs may also be unable to close their eyes, even when sleeping. MG also causes excessive drooling and difficulty swallowing due to poor muscle control.

What are the causes of myasthenia gravis in canines?

Congenital and acquired MG have different causes, but both are related to an animal’s immune system. Congenital MG is linked to few acetylcholine receptors since birth caused by a faulty immune system. This scarcity of neurotransmitters hinders the electrical signal from reaching the muscles. In turn, it inhibits muscle contraction, movements, and even basic metabolic functions.

On the other hand, acquired MG forces the immune system to produce antibodies known as the anti-acetylcholine receptor antibody (AChR antibody). The AChR antibodies attack the acetylcholine receptors needed for the transmission of nerve impulses. In other cases, cancer, thyroid problems, and autoimmune diseases trigger MG in canines.

How does a veterinarian diagnose myasthenia gravis?

Should a veterinarian notice muscle weakness from your dog, he or she may request full medical history and perform various diagnostic tests to rule out other possible conditions.

Since MG affects your pet’s entire system, a specialist may perform chemistry tests to assess the functions of the kidney, liver, and pancreas. You can also expect a complete blood count (CBC) and blood parasite screening to eliminate the possibility of blood disorders. Veterinarians will also request fecal tests to ensure that the weakness and fatigue are not caused by parasite infections.

Since thyroid problems can cause MG, a specialist will perform a thyroid test to check if your dog’s thyroid gland is producing enough hormones. Chest, abdomen, and spine radiographs are also crucial in diagnosing MG in dogs. In some cases, a veterinarian may even request an MRI or CT scan for a detailed examination of the brain and spine. 

Lastly, your dog’s veterinarian will perform a Tensilon test to evaluate MG. During the procedure, a doctor will inject Tensilon or edrophonium. Affected animals will exhibit an increase in muscle strength since the drug prevents the breakdown of acetylcholine.

Can myasthenia gravis in dogs be cured?

There is currently no cure for myasthenia gravis but there are several management strategies to effectively control its effects. Your veterinarian will present a custom treatment plan based on your dog’s medical history and the severity of the condition.

  • Medications

Usually, specialists will recommend anticholinesterase drugs to reduce the antibodies’ attack on receptors. This medication improves muscle strength but will be required for the rest of your dog’s life. Since MG also causes difficulty swallowing food and water, most pets with this condition also suffer from pneumonia.

Your veterinarian may offer antibiotics to treat pneumonia. However, if the condition worsens, he or she may recommend oxygen therapy, IV fluid therapy, and supportive care.

  • Physical Therapy

A massage is a form of physical therapy that can help ease your dog’s sore muscles. Make sure to give your pet a full body massage since MG affects the entire body. By giving them a massage, your canine friend will feel relaxed even for a short while. 

First, make sure that your dog is calm before starting the massage. Pet your dog’s entire body, then make circular motions on your pet’s neck. After that, massage your dog’s shoulders, chest, and front legs, then move to its back. Lastly, keep massaging up to the back legs and tail area.

  • Surgery

In cases of growing tumors, your veterinarian may require dog surgery. It helps prevent the spread of cancerous cells, prolonging your pet’s life span and improving its quality of life. Make sure to communicate only with board-certified veterinarians for these invasive procedures.

Myasthenia gravis is a chronic condition that affects both dogs and humans. Although there’s still no cure for MG, there are proven treatment options that can help alleviate its adverse effects. Check out TPLOInfo’s blog to know more about how you can manage and maintain your dog’s health.


Pin It on Pinterest

Share This