12 common herbs that are toxic to cats

Updated 09/09/2024

We all want our homes to be filled with lush, green plants and our kitchens stocked with fresh herbs. But did you know that some of these seemingly innocent plants can be quite dangerous for our feline friends? Cats don’t break down compounds the same way we do, which means plants and herbs we enjoy on a regular basis can cause problems for cats when ingested or even inhaled. So if you want to keep your furry friend safe and sound, read on to find 12 herbs that are toxic to cats, and what to do if your furball comes into contact with any of them. 

Herbs that are toxic to cats

1. Oregano 

Oregano might make our meat and veggies tastier, but it spells trouble for our furry friends. Whether used as an herb or essential oil, oregano can cause lethargy, vomiting, and diarrhea in cats, and can even lead to liver damage. 

2. Marjoram

Known as sweet oregano, marjoram is a staple in Greek and Italian dishes, but since it’s on this list of herbs that are poisonous for cats, you already know it’s a no-go for them.

3. Tarragon

Tarragon is another kitchen favorite that doesn’t go down well with cats – as with many of the herbs on this list, tarragon is most toxic in concentrated forms like essential oils.  It can cause drooling, vomiting, and diarrhea. 

4. Garlic, onion and chives

Okay, technically chives are the only herb in this trio, but it’s worth noting that all members of the allium family, including garlic and onion, are extremely toxic to cats. All three species can cause vomiting and diarrhea, and may also destroy a cat’s red blood cells (anemia). Symptoms of anemia include weakness, difficulty breathing, and, in extreme cases, collapse. Garlic and onions are the most dangerous of the three, as even very small amounts (less than a teaspoon) can cause harm.  

5. Lavender

Don’t be fooled by lavender’s pretty purple flowers and soothing scent, large amounts of the plant are not safe for your cat and can cause an upset stomach.

6. St John’s Wort

While St John’s Wort might boost our moods, it’s a definite no for cats. Contact with this plant can cause photosensitivity and dermatitis (similar to a severe case of sunburn) so watch out for those bright yellow flowers if you’ve got an outdoor kitty cat.

7. Foxglove

The beautiful trumpet-like flowers of the foxglove are extremely poisonous to cats, and along with vomiting and diarrhea, they can also stop the heart from beating normally. This can lead to symptoms of an increased heart rate, weakness and even collapse, which can be potentially fatal.

8. Epazote

Also known as wormseed, Jesuit’s tea, or Mexican tea, epazote is a herb that’s used to flavor Mexican dishes. However, it’s toxic for cats, particularly in the form of an essential oil, and most commonly causes vomiting and diarrhea.

9. Bay laurel

Bay laurel may look harmless, but it can cause problems for furry felines and it’s definitely not cat-friendly. Ingestion can cause vomiting and diarrhea, and eating the leaves can also obstruct your furry friend’s airways.

10. Chamomile

Chamomile, with its daisy-like flowers, is often found in skincare products and teas. However, this lovely plant can be quite harmful to cats, causing dermatitis, allergic reactions, inappetence, vomiting, and diarrhea. Long-term use can also increase the risk of bleeding issues with symptoms such as nose bleeds and black stools. 

11. Lemongrass

Lemongrass, or Cymbopogon citratus, looks a bit like a spring onion with a white bulb root and long green stems. While it’s not the most dangerous of herbs poisonous to cats, it can still upset your feline friend’s stomach. 

12. Mint

Mint is a common cooking herb that’s also found in essential oils and skincare products. Unfortunately, this fresh-smelling plant is toxic to cats, and if consumed in large amounts, it can cause vomiting and diarrhea. 

You can find a full list of toxic herbs for cats on the ASPCA (Animal Poison Control Center) website.

Signs of herb poisoning in cats

The symptoms of herb poisoning in cats can vary depending on the type of herb, how your cat came into contact with it, and how much they were exposed to. Keep an eye out for the following common signs of herb poisoning: 

• Vomiting
• Diarrhea
• Drooling
• Lethargy
• Shortness of breath
• Collapse

How to treat herb poisoning in cats

If you or your cat sitter suspect that your furry friend has come into contact with a poisonous herb, call your vet or the pet poison helpline immediately, even if your cat appears to be fine. Some symptoms can take a while to develop, so it’s better to be safe than sorry.

Treating herb poisoning in cats is one thing, but prevention is the best form of treatment. By knowing what herbs are poisonous to cats, you can either keep them out of reach or remove them from your kitchen and garden altogether. 

Herbs that are safe for cats

There are plenty of herbs safe for cats you can replace the toxic ones with. These include:

• Thyme
• Sage
• Saffron
• Cinnamon
• Rosemary
• Parsley
• Basil
• Pampas grass
• Jasmine
• Dill

As with any new food, herbs should be added slowly to your cat’s diet

Meet our veterinary expert, Liam

This article has been checked by veterinarian Dr Liam Bullock BVSc (Hons) MRCVS.

As a small animal vet, Liam has spent time working in both first-opinion and referral-level practices. After gaining a strong affinity for educating owners about their pets, Liam decided to dedicate some of his non-clinical time to tutoring students, who were preparing for exams or struggling at school. By combining a passion for teaching others, and a keen interest in raising awareness about animal health issues, Liam decided to begin writing veterinary content. This now also allows him to raise awareness of important animal health issues outside of the consultation room.