Pennyroyal Oil Poisoning in Cats

Pulegone is the toxic substance found in pennyroyal oil. When ingested, pulegone can lead to a number of different consequences including liver failure and death. Although toxicity usually occurs when pennyroyal oil is used to treat fleas, ingesting the pennyroyal plant is just as dangerous.

Pennyroyal oil is often marketed as a natural product designed to treat fleas on cats and dogs. However, it is important to remember natural is not synonymous with safe. Pennyroyal oil is toxic to cats, dogs, and even humans when ingested, so its use should be avoided.

If left untreated, pennyroyal oil poisoning can cause permanent liver or kidney damage, and in some cases, death. Cat owners should seek immediate medical attention for their pets if they begin to notice any of these symptoms:

• Vomiting
• Diarrhea
• Extreme fatigue
• Seizures
• Bloody nose
• Coughing up blood
• Unconsciousness
• Shortness of breath

Some pet owners believe pennyroyal oil is a natural alternative to harsh flea and tick medicines sold at pet stores. Therefore, pet owners often buy pennyroyal oil with the belief they are protecting their cat’s health. However, pennyroyal oil can be toxic to cats when ingested. In fact, vets believe cats are at a higher risk of pennyroyal oil poisoning than dogs. 

Although owners may believe using pennyroyal oil directly on a cat’s skin is not dangerous, there’s no way to prevent the cat from licking himself and ingesting the oil. Even a small amount of pulegone, which is the toxic substance found in pennyroyal oil, can seriously impact a cat’s health. 

Ingesting the oil is the most common cause of pennyroyal oil poisoning, however, it can also occur if your cat consumes the pennyroyal plant, which is commonly found in Europe.

If your cat begins to experience any of the symptoms of pennyroyal oil poisoning, take him to a veterinarian immediately. You will need to provide the vet with information on your cat’s diet and any products you are using on him. If you can, bring the products with you to the vet’s office so he can take a close look at the ingredients. The vet may also ask if the cat is an inside or outside cat, and what products or plants he could have ingested without your knowledge. There is no test to diagnose pennyroyal oil poisoning, so providing this information to your veterinarian is key so he can begin to narrow down what is causing your cat’s symptoms.

After the diagnosis, blood tests may be run to determine the extent of the damage to the internal organs. These tests will help the vet decide what treatment is appropriate for your cat.

Once a diagnosis has been made, activated charcoal may be given to your cat to stop the poison from spreading further into his body. Charcoal is a powerful absorbent, so when it enters the cat’s body, it begins to absorb the toxins before they are able to move into the bloodstream. 

The vet may also administer a stomach wash to induce vomiting and ensure all of the poison has been removed from your cat’s body. Your cat may be hooked up to an IV to receive fluids to prevent dehydration from the induced vomiting. 

If the pennyroyal oil was applied to your cat’s skin, the vet may also thoroughly bathe the cat to remove any excess oil that could be lingering on the skin. This will prevent your cat from ingesting more of the toxins when he grooms himself later.

Cats that have suffered liver damage as a result of the pennyroyal oil poisoning may be given N-acetylcysteine (NAC), which is frequently used to treat liver failure caused by acetaminophen. Because the effects of pennyroyal oil and acetaminophen on the liver are similar, N-acetylcysteine is believed to treat both, however, more research is needed.

There is not much documentation available on the survival rate of pennyroyal oil poisoning in cats, although it is known that cats are more susceptible to pennyroyal oil than humans and other animals. Recovery will depend on how much of the toxin was ingested and how quickly your cat was able to receive treatment. Some cats will suffer complete liver failure, while others will be able to eliminate the toxins from their bodies immediately during the treatment. The quicker you bring your cat to a veterinarian, the better his chances are of recovery.

Once you bring your cat home, be sure to remove any potential toxins from your home, including natural flea products containing pennyroyal oil and pennyroyal plants. Ask your veterinarian for recommendations on all natural, safe products that will help you treat your cat’s fleas.