5 Seemingly Harmless Substances Actually Poisonous to Cats

There are many substances that seem innocent but are actually poisonous to cats. As a cat owner, it is important to be aware of these common substances, especially because many can be found inside the home. The best way to keep your cat safe is to identify possible risks and eliminate them or keep them out of your pet's reach.

1. Acetaminophen

This substance is found in many medications including Tylenol, NyQuil and Excedrin. While acetaminophen is toxic to both dogs and cats, cats are more susceptible to poisoning because they produce less glutathione which protects cells. If high levels are ingested, the glutathione runs out causing the cells to no longer transport oxygen throughout the body.

Symptoms of acetaminophen poisoning in cats become apparent minutes to hours after ingestion. 

Symptoms include:

  • drooling
  • vomiting
  • bloody or brown urine
  • lack of appetite

Without treatment, acetaminophen poisoning can be fatal within 36 hours. 

2. Chocolate

The culprit in chocolate is theobromine which can also be found in coffee, tea, and other caffeinated products. Theobromine causes increased heart rate and overstimulates the central nervous system. A toxic dose in cats starts at 20mg per pound of cat; however, symptoms can be seen after ingesting as little as 9 mg per pound.

Symptoms of theobromine poisoning include:

  • panting
  • vomiting
  • diarrhea
  • bloating
  • restlessness
  • increased consumption of water

Symptoms are generally seen 6 to 14 hours after consumption. 

3. Baby Food

Baby foods often contain onion powder which is toxic to cats. Onions and garlic in any form contain sulfoxides and disulfides which are harmful to a cat's red blood cells. While large amounts are toxic and can be fatal, even small amounts can lead to anemia.

Symptoms of poisoning include:

  • vomiting
  • diarrhea
  • weakness
  • discoloration of urine

4. Raisins and Grapes

Toxic to both cats and dogs, grapes contain an unknown toxin which can cause renal failure or severely damage the kidneys. It is approximated that as little as .3 oz of grapes per pound can be toxic.

Like many other toxins, symptoms produced by ingesting raisins or grapes include vomiting and diarrhea. Symptoms may also include abdominal pain, reduced appetite, and lethargy.

5. Mushrooms

Mushrooms contain various toxins depending on the type. All mushrooms are extremely poisonous to cats. Mushrooms can cause serious harm to your cat including liver damage, heart damage, and kidney damage all resulting in possible fatality. Mushrooms can also cause your cat to hallucinate, become hyperactive, or go into a coma. Because there are many species of mushroom that grow in the wild, it is important to regularly inspect your yard and keep cats away from any mushrooms during meal preparation.


The symptoms associated with mushroom poisoning are very severe and include:

  • drooling
  • defecation
  • seizures
  • liver failure
  • kidney failure
  • vomiting
  • diarrhea
  • hallucinations
  • death

Signs of poisoning can become apparent minutes after ingestion.

As a cat owner, it is essential to be educated on substances that can be poisonous to your animal. Take extra precautions to keep your cat away from a substance that could be toxic. If your cat displays any of these symptoms, contact your veterinarian immediately.