Mushroom Poisoning in Cats

Cats rarely eat indiscriminately, so mushroom poisoning is rare in cats. The risks associated with mushroom ingestion are highly variable, and depend on the species of mushroom eaten. Some mushrooms are nearly always fatal, while others cause mild symptoms that resolve quickly. Cats who have eaten an unidentified mushroom require immediate veterinary care to rule out damage to internal organs from mushroom toxins.

Mushrooms that are safe for humans to eat are not expected to be dangerous for pets when consumed in moderation.

Each species of poisonous mushroom produces its own unique toxin, and each toxin has its own effect on varying internal organs. The wide variety of poisonous mushroom species means that the symptoms of mushroom poisoning are highly variable. Organ systems affected by mushroom toxins include:

• Intestines
• Liver
• Kidneys
• Nervous system
• Muscles
• Red blood cells

Similarly, each mushroom toxin varies in how long it takes for symptoms to appear. Some toxins cause symptoms within 15 minutes of ingestion, while some take up to 14 days to have an effect. In general, mushroom toxins that produce symptoms less than 3 hours after ingestion are not life-threatening. Toxins with a longer time to take effect are more likely to be life-threatening.

Several mushroom species are safe to eat, such as those purchased at the grocery store. Many other species contain toxins that damage internal organs or cause serious neurological disturbances when ingested. Mushrooms are commonly encountered in vegetated areas such as:

• Under trees
• On lawns, pastures, or meadows
• Associated with moss or decaying wood

Species of poisonous mushrooms vary by region. The most commonly ingested poisonous mushrooms are Amanita phalloides (death cap mushroom). Death cap mushrooms are common along the North American west coast. Species identification of mushrooms is very difficult without professional consultation.

Symptoms vary depending on what species of mushroom has been consumed.

Due to the variability of mushroom toxins, coming to a diagnosis of mushroom poisoning is often difficult unless the cat is known to have eaten a mushroom. Many symptoms associated with mushroom poisoning are also indicators of other toxins. In cases where mushroom ingestion is witnessed, collecting a sample of the mushroom or taking a photo for species identification is helpful. Blood and urine tests are available for the specific toxins produced by some mushroom species. Routine blood tests like a complete blood count and biochemistry profile are helpful for identifying damage to internal organs, and may provide clues about the type of mushroom eaten.

Cats witnessed eating a poisonous mushroom require immediate veterinary care. The first step is inducing vomiting, to remove the mushroom before the toxin is absorbed. There are no safe methods to induce vomiting at home in cats, so rapid veterinary intervention is essential. Gastric lavage helps rinse out the stomach and further remove toxins. Activated charcoal binds to some mushroom toxins, and is recommended in some cases.

Most mushroom toxins do not have a specific antidote available. Treatment primarily focuses on supportive care to reduce damage to internal organs while the body clears the toxin on its own.

Recovering from mushroom poisoning usually requires a 3-4 day hospital stay to monitor and treat any worsening symptoms. Depending on the type of mushroom eaten, frequent follow-up testing is required for up to a month after symptoms appear. Other treatments depend on the type of mushroom ingested, and include:

• IV fluids
• Blood or plasma transfusions
• Sedatives
• Anti-seizure medications
• Muscle relaxants

The prognosis of mushroom poisoning depends on the type of mushroom ingested. Highly toxic mushrooms such as Amanita phalloides have an extremely poor prognosis, and are almost invariably fatal once symptoms develop. Other mushrooms have a good prognosis, and symptoms often resolve quickly with appropriate supportive care. The time from ingestion to symptoms appearing and mushroom species identification are helpful indicators of the cat’s prognosis.

Mushroom toxicosis is prevented by avoiding ingestion of toxic mushrooms. Cats living an indoor lifestyle are not likely to be exposed to toxic mushrooms at all. Cats who live an outdoor lifestyle may be exposed to toxic mushrooms, especially during times of high precipitation when mushrooms are more abundant.

Mushroom poisoning in cats is rare as cats rarely eat indiscriminately.

• Fluids
• Inducing vomiting
• Activated charcoal
• Supportive care