Guide to Medications That Are Toxic to Cats
Medications, which are not meant for them, can be dangerous for cats, even in very small amounts. Cats may be exposed by accidentally ingesting pills, creams, or other medications, or by coming into contact with residues on surfaces.
When a cat is exposed to a toxic medication, symptoms can range from mild digestive upset or lethargy to severe reactions, including seizures or even death. Some medications have specific antidotes that can counteract their effects, while others require supportive care, such as fluids, supplements, or medications to manage symptoms and prevent further absorption.
While cats are often more cautious than dogs, accidental ingestion of human medications is a common cause of poisoning and should always be treated as a medical emergency.
Published October 2025 | Review date October 2028 | This advice is for UK pets only and is not a replacement for seeing a vet
Common Medications That Are Toxic to Cats
Flea and tick medication poisoning:
Pyrethroids are not safe to use on cats. Pyrethroid is permethrin are the most common topical flea and tick preparations. Toxicity commonly occurs after a canine flea/tick medication is applied to a cat. Never give your cat flea and tick medication manufactured for a dog.
Human medication poisoning:
- antidepressants, cats are attracted to a smell or flavour in the human antidepressant.
- anti-inflammatory medications, these are highly toxic to cats. Ingestion of less than half a pill can be fatal. These medications cause stomach ulcers and rapid, severe kidney failure.
- Vitamin D overdose: Vitamin D2 and vitamin D3, these forms of vitamin D are also found in topical psoriasis medications and improperly formulated pet-food diets, either commercially produced or homemade.
Signs of Poisoning in Your Cat and What to Do
Signs that might show that your cat has been poisoned include:
Twitching and fitting
Breathing difficulties
Shock or collapse
Inflammation or swelling of the skin
Depression or coma
Changes in drinking, weeing and eating
What to do if you suspect poisoning
Signs of poisoning tend to appear suddenly, so it is important to be aware. Even if you only suspect that your cat has swallowed or touched something poisonous, you must act quickly. Contact your vet immediately. Don't wait for signs of illness as by then your cat may be too sick to survive.
If you can see the poison, take your cat away from it immediately. If possible, take a sample of the poison with you to your vet appointment to help the vet choose a course of treatment.
Your vet may ask you to bring your cat in immediately or may give advice over the phone. Forcing or encouraging your cat to vomit may not be helpful and you should not try to treat your cat’s symptoms yourself.
Medications – Poisoning Prevention Tips
Keep medications, especially those with sugary coatings or chewable forms, out of your cat's reach.
Use childproof locks on cabinets and drawers that could contain toxic substances.
Ensure your rubbish cans have secure lids that cats can't open.
Use cat-safe toys by ensuring your cat's toys are non-toxic and free of small parts that could be swallowed
Regularly change water, ensuring your cat has access to clean, fresh water and change it regularly to prevent contamination.