Azathioprine for Dogs: Dosage, Side Effects, and Alternatives

Key Takeaway: Azathioprine (Imuran™) is a drug used to suppress the immune system to help treat certain auto-immune disorders. Its side effects can include vomiting, reduced appetite, fur loss, fatigue, bruising, pancreatitis, liver toxicity, increased risk of infections, and bone marrow suppression. CBD oil for Dogs may be effective in treating some of the same symptoms Azathioprine is used for.


Azathioprine (Imuran) is a drug used to suppress the immune system to help treat certain auto-immune disorders.

Azathioprine comes as a tablet in strengths of 50mg, 75mg, and 100mg.


Azathioprine is used to treat auto-immune disorders in dogs. These include arthritis, certain auto-immune blood disorders, auto-immune hepatitis, inflammatory bowel disease, lupus, and other auto-immune disorders. 


When used at appropriate doses under the guidance of a veterinarian, azathioprine is considered safe in that the benefits outweigh the risks. Azathioprine is toxic and should not be handled with bare skin. Use gloves.

Azathioprine reduces the body’s immune response, meaning that a dog may be at higher risk of infection while on the drug. It’s critical to use the exact dose the veterinarian prescribes.


Azathioprine has many side effects as the drug is toxic. These include gut side effects like vomiting and diarrhea, lack of appetite, rashes, hair loss, tiredness or fatigue, bruising or bleeding, pancreatitis, liver toxicity, increased risk of infections, and bone marrow suppression.


Azathioprine and corticosteroids like prednisone are commonly used as a last resort after everything else has failed or stacked on top of other drugs at low doses to help them continue working. For example, arthritis is commonly treated with NSAIDs or other medicines. Still, if it's rheumatoid arthritis, the immune system is attacking the dog's body – this is not something NSAIDs directly treat. Your vet may advise taking the dog off an NSAID and switching to azathioprine and a steroid or taking the dog off the NSAID and switching. Each case is different.

CBD as an Alternative
A high-quality CBD extract may help treat some symptoms of the same disorders that azathioprine treats – particularly arthritis. Using a CBD extract from a quality supplier may reduce the need to use as high a dose of toxic drugs like azathioprine if the dog's symptoms are well controlled at lower doses.

CBD is not a likely alternative for treating blood disorders or certain other auto-immune disorders, although it may help your dog's discomfort, anxiety, and pain.

A hallmark of a quality CBD supplier is the provision of third-party laboratory analysis of the product they sell lot by lot. That lets a pet owner know what is or isn't in the bottle and ensures that their dog gets the correct dose of the right substances.

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