An autoimmune disease occurs when the immune system of the dog is not functioning properly or overreacting. There are numerous autoimmune diseases and these will be diagnosed based on the symptoms presented by the dog and by performing a few specific tests. Autoimmune diseases are difficult to diagnose, as the symptoms may often indicate different illnesses. Typically, autoimmune diseases are suspected only after other more probable illnesses have been ruled out.
The Immune System
The immune system in canines is responsible for fighting off infections and foreign proteins and bodies. The immune system is made up of several compounds, including the liver and the kidneys that have the task of filtering toxins and protecting the body from them. The lymphatic system is also an active part of the immune system.
Autoimmune Diseases
Autoimmune diseases in dogs occur due to a malfunction of one or more components of the immune system. The immune system will no longer be able to tell the difference between foreign bodies and internal bodies and this will disrupt the normal secretion of antibodies. The body will form auto antibodies that will start destroying the dog's body. The autoimmune disease may affect one or more organs or may be present in the dog's blood, affecting the entire system.
There are several autoimmune diseases in dogs such as Addison's disease, lupus, skin autoimmune diseases, rheumatoid arthritis and allergies.
Symptoms of Autoimmune Diseases
The symptoms of autoimmune diseases may depend on the type of disease affecting the dog. However, the dog may suffer from behavioral changes and he may be overly agitated or lethargic. Other symptoms of an autoimmune disease may include:
- Vomiting, with blood in some cases
- Diarrhea, may contain blood
- Skin rashes and irritation
- Exercise intolerance
- Fever
- Skin or mucous membrane lesions
- Ulceration
- Joint pain and stiff joints
- Seizures
- Lack of appetite
- Weight loss
- Foul body odor
- Muscular pain and difficulty performing certain movements
The symptoms may occur only when the disease is more advanced. The early stages of the disease may only present a few subtle symptoms that can pass unnoticed. The dog's symptoms may often point to different other conditions, and this is why the diagnosis of autoimmune disease is difficult.
Diagnosing Autoimmune Disease
A few blood tests may cast a light on what causes the symptoms and whether the dog is affected by an autoimmune disease or some other health condition with similar symptoms.
Blood tests will be performed to detect any possible abnormalities caused by an autoimmune disease. The level of thyroid hormones and adrenaline will also be measured. An antinuclear antibody (ANA) test is required to determine if the dog is affected by lupus. The vet may perform different tests that will involve all organs to determine if the disease affects a single organ or multiple organs. X-rays, ultrasounds, MRIs and CT scans may also be performed.