Fungal Toxicosis Related to Fusarium Fungus in Cats

By PetMD Editorial on May 22, 2010

Mycotoxicosis-Deoxynivalenol in Cats

Deoxynivalenol (DON), also known as vomitoxin for its effect on the digestive system, is a mycotoxin produced by the fungus Fusarium graminearum in grains such as corn, wheat, oats, and barley. Mycotoxicosis is the medical term used to describe a diseased state that is brought on by a mycotoxin, a toxic chemical that is produced by a fungal organism, such as molds and yeasts. Mycotoxicosis-deoxynivalenol refers to the toxic reaction that results when a cat ingests pet food that was made with DON-contaminated grain.

Symptoms and Types

Known symptoms of mycotoxicosis-deoxynivalenol include a sudden refusal of food and/or vomiting after the ingestion of food contaminated by DON. The refusal of food with concurrent vomiting may also lead to subsequent weight loss. Note that if the contaminated food is removed and no longer given, these abnormal signs may resolve and no treatment will be necessary.

Studies have shown that vomiting in cats is common if DON concentration in food is greater than eight milligrams per kilogram of food.


Mycotoxicosis-deoxynivalenol is caused by the ingestion of grains (for example, barley, wheat, corn or oats and other grains commonly used in the production of pet feeds) that are contaminated by the fungus known as Fusarium. This fungus may react in the body in a toxic manner, leading to symptoms such as vomiting, refusal of food, and weight loss.


You will need to give a thorough history of your cat's health and onset of symptoms. Diagnosis of mycotoxicosis-deoxynivalenol can be achieved by analyzing the suspected cat food for the presence of DON. Other diagnostic procedures that may rule out diseases with similar symptoms to those of mycotoxicosis-deoxynivalenol (namely inappetite and vomiting) include X-rays, chemical blood profile, and urine analysis.

Alternate diagnoses may include an infection due to virus, bacteria, or parasite, exposure to various toxins (such as ethanol poisoning), ingestion of poisonous plants (lilies for cats for example), tumors or other abnormal cell growths, or an infection of the pancreas.


This condition can generally be solved simply by removing the contaminated cat food, which should result in a quick end of vomiting and a return to normal appetite and food intake. If this is done, no need for further treatment or medications should be necessary.

Living and Management

If mycotoxicosis-deoxynivalenol has been diagnosed, and the problem addressed via removal of the contaminated food, it will still be important for your veterinarian to check your cat's symptoms. Severe vomiting can lead to dehydration for example, in which case body fluids will need to be replenished before any of the internal organs are damaged. If weight has been lost due to vomiting or lack of appetite, your veterinarian will want you to watch your cat carefully, as cats are at particular risk of severe complications when they have gone without food for more than a day. Your cat's weight will also need to be monitored to ensure that expected normal weight gain occurs during the recovery period.


This is a preventable disease. Mycotoxicosis-deoxynivalenol can be avoided by feeding only high-quality cat foods that are free of DON. 

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