Auto-immune diseases, those where the body attacks its own tissues, have received significant attention recently due to the impact they are having on the health of our society.
At the Animal Referral Hospital Brisbane we frequently see auto-immune disease in animals, and it can be a shock for owners when they discover the reason for their pet’s symptoms.
Tatanka’s owner Chrissy brought him into our emergency vet hospital with severe lameness, lethargy and swollen joints.
He was referred to our internal medicine specialist, Dr Emily Cook, who performed a range of tests including collecting fluid samples from his joints. She found that he had severe inflammation in a number of his joints and with no infection present he was diagnosed with immune-mediated polyarthritis.
This auto-immune condition can affect any breed of dog and occurs when a dog’s immune system targets its joints making them swollen and painful. If left untreated this condition can seriously affect a dog’s health and in severe cases can lead to early death.
Tatanka was put on medications to suppress his immune system which he has responded to well. He has started going on walks with Chrissy again and we have begun weaning him off his cortisone. We will slowly wean his medication over many months and it is possible he may come off his medication altogether.
However, the outcome is unkown and Chrissy is prepared that this may be a lifelong condition that needs to be medically managed.
What type of auto-immune diseases affect animals?
Auto-immune disease refers to a broad range of conditions in which the immune system attacks its own tissues. The most common auto-immune diseases we see in animals are those that target:
- Red blood cells (immune mediated haemolytic anaemia)
- Platelets (immune mediated thrombocytopaenia)
- Joints (immune mediated polyarthritis)
How is an auto-immune disease diagnosed in animals?
There are a wide range of symptoms that can indicate the presence of an auto-immune disease in animals. For the main types listed above, the following symptoms are often present:
- Targeting red blood cells: Pets are pale and lack energy and sometimes can be jaundiced.
- Targeting platelets: Pets have bruises on their gums or skin and can have black, tarry stool.
- Targeting joints: Pets have pain on standing or a reluctance to walk.
Given the complexity of auto-immune diseases the symptoms a pet experiences can be very individual. As an owner, you know your pet the best. So if you think they are acting differently, or you notice changes to their body, we recommend seeing your vet to have your pet checked out.
If an auto-immune disease is suspected, your vet will conduct a range of tests which may include blood/urine tests and abdominal/chest imaging to look for underlying triggers of disease. Further testing will depend on the individual patient. In dogs with suspected immune mediated polyarthritis, fluid is removed from the joint to assess it for increased numbers of cells and to look for infectious causes.
Why do animals get auto-immune diseases?
As with humans, in many of our cases we are unable to find a trigger for the onset of an auto-immune disease.
We look for reasons such as recent vaccinations or medications, or inflammatory or cancerous causes. We usually conduct a chest x-ray and an abdominal ultrasound to look for a focus/potential trigger, but in many cases we don’t find one.
Identifying an underlying trigger is important as this can alter a pet’s treatment and outcome.
What is the treatment for auto-immune disease in animals?
The treatment will depend on the type of auto-immune disease being addressed and typically involves one or more medications to suppress the immune system. The aim here is to weaken the immune system and thus stop it from attacking the body.
Over time we attempt to wean an animal off their medication in the hope that the immune system will continue functioning normally. Unfortunately, this can be a precarious process and management of an auto-immune disease is often a life-long process. Even if we are able to wean an animal off their medication the potential for flare ups means they need to be continually monitored throughout their life.
Animals on medications that suppress the immune system are also more susceptible to secondary infections and need close monitoring by their veterinarian.
Thank you to the Charlotte Reeves Photography: Tails Of Brisbane project for supplying the photos of Tatanka.