Autoimmune Disease in Dogs

What Is Autoimmune Disease in Dogs?

An autoimmune disease occurs when the immune system, responsible for protecting against foreign invaders, mistakenly targets its own body’s proteins and cells instead of external threats.

This immune response creates immune complexes that can harm tissues and organs, leading to various symptoms. 

While not typically an immediate emergency, untreated autoimmune diseases can have serious consequences that can be fatal. 

Types of Autoimmune Disease in Dogs

Autoimmune diseases can manifest in various ways, affecting different parts of a dog’s body. Some common types include:

• Pemphigus foliaceus: Targets skin cells, causing cracks, fissures, pustules, scaling, and infection

• Pemphigus erythematosus: Affects skin on the face, particularly in certain breeds like German Shepherds, Collies, and Shetland Sheepdogs

• Pemphigus vulgaris: Rare and severe; can lead to skin lesions, including erosions and vesicles, affecting various parts of the body, including the lips, nose, nailbeds, and other skin areas

• Bullous pemphigoid: Separates the top and middle layers of the skin

• Systemic Lupus Erythematosus (SLE): Affects multiple systems, creating symptoms including lameness, skin lesions, anemia, kidney failure, and seizures

• Discoid Lupus Erythematosus (DLE): A benign form of lupus that affects the skin of only the nose and face

• Myasthenia gravis: Impairs neuromuscular junctions, leading to muscle weakness that can manifest as difficulty eating or swallowing, regurgitation, and generalized limb weakness that often is worsened with exercise

• Granulomatous Meningoencephalitis (GME): Inflammation that typically affects the blood vessels of the brain and spinal cord, causing seizures, blindness, circling, and abnormal gait

• Masticatory myositis: Targets muscles used for chewing; typically affects large-breed dogs and leads to painful and swollen muscles, a reluctance to eat, difficulty swallowing, and eventual weight loss

• Glomerulonephritis: Impacts kidney function, and includes symptoms associated with kidney failure, such as an increased thirst and urination, muscle wasting, lack of appetite, and swelling of the limbs and abdomen

• Polyarthritis: Causes joint inflammation, triggering lameness and arthritis

• Uveodermatologic syndrome (Vogt-Koyanagi-Harada-like Syndrome): Targets melanin pigment and frequently results in blindness, affecting breeds such as the Akita, Old English Sheepdog, Golden Retriever, Husky, and Irish Setter

• Keratoconjunctivitis sicca (KCS): Commonly referred to as “dry eye”; occurs in about 1% of the canine population, and more so in Shih Tzus, Cocker Spaniels, Boston Terriers, and Pekingese

• Pannus (chronic immune-mediated superficial keratitis): A progressive, non-curable disease that damages the cornea and leads to blindness

• Immune-Mediated Thrombocytopenia (ITP): Affects platelets, the cells responsible for blood clotting, leading to extensive bruising and potentially hemorrhage

• Immune-Mediated Hemolytic Anemia (IMHA): Impairs the red blood cells, which carry oxygen to the tissues, resulting in weakness, pale gums, difficulty breathing, and/or collapse

While IMHA, ITP, and pemphigus foliaceus occur in dogs more commonly than other autoimmune diseases, overall, autoimmune disease is uncommon in dogs.

Symptoms of Autoimmune Disease in Dogs

Dogs suffering from an autoimmune disease will experience symptoms associated with the organs or cell functions targeted by the immune system.

Some symptoms can occur sporadically, worsening over time, and some can occur suddenly.

Though not an exhaustive list, depending on the area under attack by the immune system, dogs commonly will show symptoms including:

• Anemia (low red blood cell count)

• Blood in the urine or stool

• Bruising and pinpoint hemorrhages seen on the gums or skin (petechiae)

• Collapse

• Decreased appetite

• Depigmentation of the skin and nose

• Difficulty breathing or an increased respiratory rate

• Difficulty eating

• Enlarged lymph nodes

• Erythema (redness) of the skin

• Fever

• Hair loss

• Increased heart rate

• Kidney failure

• Lameness

• Lethargy

• Mouth ulcers and bad breath

• Muscle atrophy

• Pale gums

• Painful or stiff muscles and joints

• Scaling, redness, crusting, and skin ulcerations

• Seizures

• Sneezing, often with blood (epistaxis)

• Swelling of the limbs or abdomen

• Vomiting

Causes of Autoimmune Disease in Dogs

Autoimmune diseases can affect any breed, but they are more frequently observed in unspayed females.

Contributing factors include genetics (with a higher occurrence in purebreds), cancer, or environmental influences like UV light, infections, medications, or other medical therapies.

Dogs diagnosed with one autoimmune disease are more likely to develop other immune-mediated diseases.

How Veterinarians Diagnose Autoimmune Disease in Dogs

Diagnosing autoimmune diseases can be challenging.

Such a diagnosis is often made through a process of exclusion, which means that other possible causes are ruled out and the true underlying cause remains unknown.

Veterinarians typically use blood work, urine tests, and other screenings to identify potential issues. In some cases, a biopsy or advanced imaging such as a CT scan or MRI may be necessary.

While not all tests are 100% confirmatory, when analyzed together with the symptoms, there can be sufficient information to make an immune-mediated diagnosis. 

Treatment of Autoimmune Disease in Dogs

Because autoimmune diseases occur due to an over-reactive and inappropriate immune system, treatment aims at suppressing the immune system.

This is often approached using prescription medications called immunosuppressants.

Steroids at high doses are the most prescribed drug and the most effective, though they have adverse side effects.

To minimize or avoid these side effects, other immunosuppressive drugs may be used in conjunction with steroids.

Because certain drug combinations appear to work better for specific conditions and have a variable response in the individual, be sure to partner with your veterinarian for the best therapy options for your dog. 

Because many dogs suffering from the negative effects of autoimmune disease experience pain or discomfort and poor quality of life, pain medications will often be prescribed.

Many dogs with autoimmune disease also have secondary infections, and antibiotics may be needed. 

Additionally, topical therapies such as ointments, shampoos, or conditioners are often prescribed in conjunction with oral medications as an effective way to target localized lesions and decrease the dose of oral medications.

Affected dogs typically don’t require a change of diet or supplements, but some dogs with long-lasting kidney issues or glomerulonephritis can benefit from prescription diets such as Royal Canin Renal.

Dogs affected by IMHA or ITP may require supplementation with iron or vitamins.

In the acute hospital setting, dogs may require:

• Blood transfusions

• IV fluids

• A feeding tube

• Medication to prevent seizures

• Anticoagulants to help prevent blood clots

• Anti-nausea and antiemetic medications to prevent vomiting

• Oxygen therapy

• Therapeutic abdominocentesis, where fluid is drained from the abdomen

• Thoracocentesis, where fluid is drained from the body.

Recovery and Management of Autoimmune Disease in Dogs

Autoimmune diseases vary in prognosis.

For example, dogs with DLE typically show improvement within eight to twelve weeks.

However, those with myasthenia gravis have about a 33% chance of improving, going into remission, or not surviving. Complications from the disease and the treatment itself can lead to the humane euthanasia of many dogs. 

While autoimmune diseases are not curable, they can be managed with lifelong medications.

It may take months to see significant improvement.

Once symptoms are resolved, your veterinarian may recommend tapering drug therapy to the lowest effective dose to manage symptoms while minimizing side effects.

Relapses can occur, but tapering drugs benefits your dog in the long run.

Regular follow-up and monitoring are vital to prevent relapse and assess drug side effects. Always adhere to your vet’s recommendations and consult them before discontinuing or self-tapering medications.

Prevention of Autoimmune Disease in Dogs

Unfortunately, most autoimmune diseases cannot be prevented, but a prompt diagnosis followed by immediate treatment can be lifesaving.

Be sure to have your dog examined by their vet at the first sign of a problem.

Be sure to follow your veterinarian’s recommendations for recheck examinations to minimize relapses.

Additionally, make sure that all veterinary providers are aware of your dog’s condition and what medications they are taking.

Certain medications and vaccines have the potential to exacerbate the condition or cause recurrence of the disease.

Since suppressing the immune system can increase the risk of developing other infections like urinary tract infections, regular screening and monitoring for potential infections are essential for your dog’s long-term health.

UV light can also exacerbate certain diseases, so try to limit sun exposure by walking your dog in the early morning or late evening and use a pet-approved sunscreen on the bridge of the nose and non-haired skin when necessary.