Fungal Toxicosis in Cats

Fungal toxicosis is a disease caused by toxins that are created by fungi and molds. The condition occurs when fungus or spores enter the body, usually through inhalation or ingestion, and create mycotoxins, which damage internal systems. The condition is also called mycotoxicosis. Fungal toxicosis is more common in warmer climates. The fungus that causes these conditions is often found on foods, grains, or bedding materials. Cats experiencing fungal toxicosis will generally require medical attention. Symptoms can range from moderate to severe and can be fatal in some cases.

The symptoms of fungal toxicosis can vary depending on the type of fungus and the manner in which it entered the cat’s system. In cases where the toxin is ingested, early symptoms are generally gastrointestinal in nature. If the toxin is inhaled, respiratory symptoms are more common. In most cases, continued exposure or lack of treatment results in a worsening of symptoms and can lead to neurological issues and even death. 

Symptoms Include:

• Lack of appetite
• Vomiting
• Diarrhea
• Weight loss
• Dehydration
• Blood in feces
• Abdominal bloating
• Nasal discharge
• Bloody nose
• Sneezing
• Difficulty breathing
• Rapid breathing
• Fever
• Confusion or abnormal behavior
• Slow growth
• Weakness
• Lethargy
• Incoordination
• Tremors or seizures
• Coma
• Liver toxicity
• Death

Types

Several types of fungus can cause toxicosis in cats, including molds and mushrooms. Some varieties known to cause issues for cats and other companion animals include:

• Aspergillus mold
• Fusarium fungi
• Penicillium fungi
• Amanita muscaria or Fly Agaric mushroom
• Amanita pantherina or Panther Cap mushroom

The primary cause of fungal toxicosis is ingesting or inhaling toxin-producing fungus or spores. Fungal toxicosis is more common in warmer climates and areas with high moisture or humidity. The most common cause of fungal ingestion comes from moldy pet foods, grains, corn, or nuts. It is also possible for the cat to ingest mushrooms while outdoors. Bedding like straw, cotton, or other materials can also become infested with fungus, causing both ingestion and inhalation risks. Once the mycotoxins from the fungus or spores are in the cat’s system they poison the body, resulting in observable symptoms. 

Your veterinarian will use several diagnostic methods to determine if fungal toxicosis is the cause of your cat’s symptoms. Numerous other conditions, including bacterial infections, viral infections, and some cancers, can cause similar symptoms in cats. Be prepared to discuss your pet’s medical history, living environment, symptoms, and the timeline associated with those symptoms. Before visiting the veterinarian, check for signs of mold or fungal growth in your cat’s food, bedding, and areas where they spend a lot of time. Bring a sample of anything you suspect may have molded and come into contact with your pet. 

Imaging technologies like CT scans or MRI may be used to look for changes associated with fungal infection. Veterinary staff may also analyze blood, tissue, urine, feces, and mucus for signs of fungi or antibodies commonly produced to fight fungal infections. If fungal toxicosis is suspected, testing will be conducted to identify the type of fungus and determine the extent of the damage to your pet’s bodily systems. Special attention will be paid to the liver, including diagnostic imaging and potentially biopsy, as the liver is commonly affected by mycotoxins. 

Fungal toxicosis treatments vary depending on the type of fungus, how it was introduced to the cat’s system, and the symptoms observed. Fungi that have infected the respiratory and sinus system through inhalation are often treated with topical antifungals, whereas ingested fungi require oral medications. Depending on the severity of symptoms, your cat may require hospitalization. Some treatment options include:

Oral Antifungal Medication

Dosing with an oral antifungal medicine is the primary treatment in fungal toxicosis. This category of medication helps to kill off the fungus in the cat’s system, alleviating symptoms and helping stop further damage. Treatments may go on for several weeks or months. Monitoring of kidney performance may be required as antifungals can increase the risk of kidney damage. 

Antifungal Sinus Infusion

This treatment is most often used in cases where the fungus has been introduced through the respiratory system. This treatment is common with Aspergillus molds. Under anesthesia, a breathing tube is inserted, and the sinuses are blocked. Veterinary staff will then flood the sinus passages with a topical antifungal solution. The treatment will take over an hour to complete and may require multiple applications. 

Gastric Lavage and Suction

Often referred to as 'pumping the stomach', this treatment is used to remove any ingested toxic material after a recent ingestion. This treatment is commonly used if toxic mushrooms have been ingested, but may also be used in the case contaminated food is suspected. The greatest risk is gastrointestinal distress. 

Intravenous (IV) Fluids

Fluid therapy may be used to prevent dehydration, provide essential nutrients, and administer medications. IV fluids will be used in cases where vomiting, diarrhea, or lack of appetite has occurred. This practice carries a low risk of side effects. 

Symptomatic Treatments

Other treatments or medications may be prescribed to treat the various symptoms associated with fungal toxicosis. Treatments for seizures, pain, or fever are common. Your veterinarian may also recommend dietary changes. 

If fungal toxicosis is treated promptly and further exposure is prevented, the prognosis for recovery is generally good. In severe cases or those with long term exposure, permanent internal damage may occur. To prevent further exposure, remove and dispose of moldy foods and bedding materials. Thoroughly clean the cat’s living area to ensure any potential sources of fungus or mold have been eliminated. In the event your pet ate mushrooms found outdoors, take care to get rid of any mushrooms you observe in areas your cat frequents and have your cat checked over by a vet right away. Be sure to follow all of your veterinarian’s instructions, including continued dosing of medications. If dietary changes were recommended, ensure that your cat is receiving the proper nutrition that they need to recover. Continue to monitor your pet and seek veterinary assistance if symptoms worsen, return, or do not get better.