Myasthenia Gravis in Dogs (13 Questions & Answers)

If your dog has experienced fatigue, weakness, or trouble eating lately, you may not realize that these seemingly mild symptoms can sometimes be attributed to a disorder that affects the esophagus and other parts of the body known as Myasthenia Gravis, and these signs should be discussed immediately with your vet.

Myasthenia Gravis in dogs is a neuromuscular disease caused by a malfunction in the signal transmission between the nerves and muscles, resulting in fatigue and muscle weakness. A common symptom of MG is a dilation of the esophagus known as megaesophagus which causes food to be held before passing through to the stomach, causing dogs to retch and face difficulties swallowing and drinking.

The good news is that Myasthenia Gravis can be treated in dogs, but this requires surgery and life-long medication to ensure the muscles can function properly. Carefully controlled feeding will also be necessary to prevent regurgitation and other complications. If you’re concerned your dog may be showing signs of this disorder or they have recently been diagnosed, we hope this guide can answer your queries.

What is Myasthenia Gravis in Dogs?

Canine Myasthenia Gravis is a condition that essentially breaks down the transmission signals between a dog’s nerves and muscles.

This happens when dogs are deficient in acetylcholine receptors in the body (membrane proteins that bind to the neurotransmitters in your dog’s brain).

When these receptors are lacking on the surface of a dog’s muscle cells, muscles can weaken throughout the body, though most commonly in their esophagus.

There are two types of Myasthenia Gravis:

Congenital Myasthenia Gravis

This form is present at birth and will become apparent in puppies between 6-8 weeks old.

Congenital MG can present itself in any breed but is most common among Jack Russell Terriers, Springer Spaniels, and Smooth Fox Terriers.

Early signs are often a progressive weakness after exercise that can lead to paralysis and death if untreated.

Acquired Myasthenia Gravis

Acquired MG is when the condition presents in later life due to genetics or environmental factors, and is typically diagnosed in dogs between the ages of 1-4 years or between 9-13 years old.

Acquired Myasthenia Gravis is more common than Congenital MG.

How Long Can Dogs Live with Myasthenia Gravis?

Thankfully, the prognosis for most dogs living with Myasthenia Gravis is generally positive except in rare cases. With early detection and treatment, dogs with MG can expect to recover fully within 6-8 months and go on to have a normal life expectancy.

If your dog’s condition fails to improve within the first month of diagnosis, however, their severely weakened state can put them at greater risk for a rare complication of MG known as aspiration pneumonia.

Aspiration pneumonia occurs when food, saliva, and vomit is accidentally and inhaled and this can worsen the overall prognosis.

Additionally, if an underlying cancer associated with MG known as thymoma is detected, your dog’s life expectancy will be impacted by the efficacy of the tumor removal and subsequent treatment.

MG is treatable in dogs, but a normal life expectancy is only achievable with a life-long prescription of anti-acetylcholinesterase medication (to decrease the breakdown of transmission signals) and immunosuppressive therapy.

Dogs with MG will also require a special feeding technique which we’ll discuss further on.

How Does a Gog Get Myasthenia Gravis?

Dogs are either born with Myasthenia Gravis due to a reduced number of acetylcholine receptors in their bodies, or they develop MG in later life due to a combination of hormonal influences and environmental factors which can cause the production of antibodies that destroy some of these receptors.

The dog breeds that are predisposed to acquired MG later in life are:

• Golden Retrievers
• Great Danes
• Akitas
• Dachshunds
• German Shepherds
• Labrador Retrievers
• Scottish Terriers
• Newfoundlands

In rare cases, Canine Myasthenia Gravis can also be a secondary condition of cancer, most commonly with a chest tumor known as a thymoma. Non-spayed/neutered female dogs can also be at higher risk of acquired MG, and according to a piece published in Veterinary Partner “vaccination should be postponed as it has been shown to exacerbate active Myasthenia Gravis.”

Symptoms of Myasthenia Gravis in Dogs

Because MG primarily affects the esophagus your dog will typically show symptoms such as trouble swallowing and drinking, retching, abdominal contractions associated with vomiting and regurgitation. However, dogs with Myasthenia Gravis can also exhibit the following:

• Vocal changes (high-pitched barking)
• No gag reflex
• Excessive drooling
• Weakness, cramping, or collapsing after exercise
• Difficulty breathing
• Inability to blink or close their eyes (even when sleeping)
• Desire to rest more than move
• Difficulty walking

Early Signs of Myasthenia Gravis in Dogs

Whether MG is congenital or acquired, the earliest signs to look out for in your pooch should be a generalized weakness in their body (all over). You may notice that they tire out after exercise and play quicker than usual and begin to have difficulties swallowing their food, so be on the lookout for subtle changes in their activity levels and eating habits.

Is Myasthenia Gravis Painful in Dogs?

Dogs are more likely to experience discomfort rather than pain with Myasthenia Gravis.

Due to the muscle weakness, they can tire out easily after exercise and their hind limbs can become stiff which can naturally make them feel sore, so you could help relieve their discomfort with massage therapy.

Additional symptoms of difficulty swallowing food and regurgitating will of course be unpleasant but it should not be painful, so keep in contact with your vet about any changes to their MG symptoms.

How Common is Myasthenia Gravis in Dogs?

Canine Myasthenia Gravis is unfortunately very common, which is why it’s crucial that dogs showing any signs of muscle weakness and difficulties swallowing are tested for possible MG.

Is Myasthenia Gravis Fatal in Dogs?

Myasthenia Gravis may only be fatal in dogs if the above-mentioned complications of cancer or pneumonia become severe. The first month of their diagnosis will be crucial in predicting their prognosis as they will be at their weakest during this period.

Dogs can sometimes even be spontaneously cured of MG overtime, according to a neurological study that found 47 out of 53 dogs went into spontaneous clinical and immunologic remission from the disease.

Is Myasthenia Gravis Hereditary in Dogs?

Though it’s rare, Myasthenia Gravis can be inherited in the form of a congenital defect passed on to pups of certain breeds. MG has been noted as a recessive genetic disease in the following breeds: Jack Russell Terriers, Miniature Dachshunds, Springer Spaniels, and Smooth Fox Terriers.

Is Myasthenia Gravis in Dogs Contagious?

Myasthenia Gravis is currently not thought to be contagious in dogs, though it can sometimes affect more than one member in the same family.

Myasthenia Gravis Dogs Treatment Cost

It’s estimated that the average cost to treat Canine Myasthenia Gravis is around $5,000, based on more than 400 quotes ranging from $3,000-$15,000.

For acquired cases of MG where normal recovery is expected, the main expenses are in the life-long medication.

In more complex cases of MG, however, the diagnostic costs alone can range between $500-$2,000, and if underlying cancer is detected or aspiration pneumonia develops, this can increase costs due to surgeries, therapies, and possible intensive care needs.

Natural Remedies for Myasthenia Gravis in Dogs

While there isn’t a wealth of supplements and natural treatments out there for Myasthenia Gravis, there have been case studies on the effects of Chinese herbal medicines and homeopathic remedies treating the primary symptom of MG (megaesophagus) in dogs.

In one such study, a 4-month-old Havachon puppy that had not responded to conventional treatment showed decreased symptoms of regurgitation after one week on the herbal formula.

In another case, a 2-year-old Siberian Husky with recurring symptoms of gagging, lethargy, and vomiting reported decreased regurgitation and weakness with a course of herbal remedies alongside acupuncture treatment.

Best Food for Dogs with Myasthenia Gravis

Because Myasthenia Gravis is an auto-immune disease (in which the immune system mistakenly attacks the body), your dog will benefit from a diet that calms and balances his immune system.

A light amount of wet food is best as this will reduce the amount they regurgitate and therefore reduce the risk of aspiration pneumonia. Include foods like:

• Fresh & plant-rich meals over dry kibble
• Raw meaty bones
• Steamed or ground organic veg
• Filtered or spring water over fluoride and chlorine-contaminated tap water
• Chicken, animal fats and fish oil containing omega-3
• Bananas, yogurt and honey

…because these contain:

Antioxidants – to help the immune system destroy free radicals without stimulating an immune response.

Enzymes – to aid digestion and maintain a balance of disease-fighting bacteria.

Probiotics – for optimal nutrition and to help good bacteria thrive.

Essential fatty acids – to provide the first line of defense for the immune system and support the digestive tract.

Feeding Technique

Help gravity make up for your dog’s faulty esophagus by feeding them by hand in an elevated position. This is easier to do for smaller breeds, but larger breeds with MG can benefit from a Bailey chair (almost like a standing high-chair for doggies!). Placing food in elevated bowls is recommended, but this may not be enough for severe cases.

After feeding, it’s important to ‘burp’ them like a baby and let them rest in an elevated position for at least 10 minutes to allow the food to go down, either sat in their Bailey chair or sat upright with your support on the couch.

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