Aspirin Poisoning in Cats

By PetMD Editorial. Reviewed by Hanie Elfenbein, DVM on Feb. 25, 2019

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Updated on February 25, 2019

Aspirin, a non-steroidal anti-inflammatory medication, has been found to have beneficial effects for some animals. It has been used for conditions related to blood clotting and inflammation, and for its analgesic (pain-relieving) properties. However, aspirin for cats can actually be toxic.

Aspirin should only be given to cats under strict veterinary supervision. On its own, aspirin can be toxic to cats. In combination with other medications, the effects of aspirin can be more rapid.

Once ingested, aspirin forms salicylic acid, which is then distributed throughout the body. Aspirin toxicity is a particular concern in cats because they lack the enzyme critical for metabolizing salicylic acid properly.

Cat owners must follow their veterinarian's orders strictly if cat aspirin is prescribed for any reason.

Symptoms and Types of Cat Aspirin Toxicity

The progression of symptoms can occur quickly. Frequently, one of the first noticeable signs is loss of appetite.

Other signs of aspirin toxicity in cats include vomiting and diarrhea, brought on by ulceration in the stomach and small intestines. The vomit or diarrhea may have fresh blood (red) or digested blood (dark brown to black) in it.

The central nervous system may also be affected, causing your cat to have trouble walking, appear weak and uncoordinated, or even collapse. Loss of consciousness and sudden death can also occur.

Even dosed at the appropriate amount, aspirin for cats can produce these symptoms, therefore it is imperative for you to monitor your cat for any digestive problems or changes in behavior when giving aspirin that is prescribed by a veterinarian.

If a significant amount of aspirin is ingested, emergency medical treatment will be necessary.


If you know, or even suspect that your cat has ingested aspirin, and your cat is showing apparent symptoms of toxicity, contact an emergency veterinarian immediately.

Diagnostic tests should focus on determining the severity of the toxicity. A blood profile will be conducted, including a chemical blood profile, a complete blood count and a urinalysis.

Often an affected cat will be anemic (low red blood cell volume) with electrolyte abnormalities, in addition to showing a reduction in the blood's ability to clot properly. Aspirin reduces blood flow to the kidneys, which can cause or worsen existing kidney disease.


Cats treated within 12 hours of ingestion, and who are presenting limited signs of distress, can have the concentration of aspirin in the body decreased through a prescribed treatment of decontamination. The sooner this care begins, the better.

Your veterinarian may recommend that you decrease the amount of aspirin in the body by inducing vomiting at home before coming to the clinic, or the vomiting may be induced in the clinic.

By inducing vomiting, or pumping the stomach (gastric lavage), your veterinarian will be able to remove as much aspirin as possible, which will help with lowering the chances of permanent injury.

Activated charcoal may be given after vomiting to absorb some of the remaining aspirin.

Depending on your cat's status, fluids and other supportive treatments may be necessary. Hospitalization and repeated blood analysis will often be standard until your cat is stable.

Prescription pet medications to encourage healing, or to protect the gastrointestinal lining, are also generally prescribed both in the clinic and for a period of time after returning home.

Living and Management

Aspirin for cats has several clinical uses. It can be prescribed as a pain reliever, an anti-inflammatory and an anti-blood clotting agent. It can also be used for lowering an abnormal body temperature.

Regardless of why your cat is being prescribed aspirin, it is important to follow your veterinarian’s directions precisely. This includes the type of tablet because certain kinds of coating may increase the risk of toxicity in your cat.

Reducing or discontinuing the aspirin dosage may be necessary if your pet is showing a susceptibility to toxicity.

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