Can Cats Eat Pesto?

No — traditional pesto is not safe for cats because it often contains garlic, which is more toxic to cats than dogs, and it is also high in fat and dairy that can upset the stomach.

Urgent

Pesto is not safe for cats

Traditional pesto commonly contains garlic, and allium ingredients like garlic are especially dangerous for cats because they can damage red blood cells and cause anemia. Even when garlic is not listed, pesto is still a poor choice for cats because it is oily, rich, and often contains cheese or nuts that can trigger vomiting or diarrhea.

How urgent is this?

Emergency

Go to the ER now

  • Cat ate a large amount of pesto or concentrated pesto sauce
  • Pesto definitely contained garlic, garlic powder, onion, onion powder, chives, or leeks and your cat is weak, pale, breathing fast, collapsing, or not responsive
  • Signs of anemia or poisoning such as pale gums, severe lethargy, collapse, or dark urine
Urgent

See a vet within 24 hours

  • Your cat ate any meaningful amount of pesto that contains garlic or onion
  • Your cat is vomiting repeatedly, has diarrhea, seems painful, or will not eat
  • You are not sure of the ingredients in the pesto
  • Your cat has underlying illness, is very small, or may have eaten pesto repeatedly over several meals
Monitor

Watch at home, call if it worsens

  • Your cat only licked a tiny smear once and is acting completely normal
  • The pesto was confirmed garlic-free and onion-free, but your cat may still develop mild stomach upset from the oil, cheese, or nuts
  • Monitor closely for vomiting, diarrhea, poor appetite, lethargy, or pale gums over the next 1-5 days and call your vet if anything seems off

Why Pesto Is Dangerous for Cats

The biggest concern is garlic. Cats are more susceptible than dogs to allium toxicity, and garlic is more potent than onion. These compounds cause oxidative damage to red blood cells, which can lead to Heinz body hemolytic anemia. Signs may be delayed for several days. On top of that, pesto is not appropriate for obligate carnivores and may cause stomach upset because it is rich in oil, dairy, and sometimes nuts. Basil itself is not toxic to cats, but that does not make pesto safe.

  • Garlic and other alliums can damage red blood cells and cause anemia in cats
  • Cats are more susceptible to allium toxicity than dogs
  • Garlic is more toxic than onion, and powdered or concentrated forms can be especially risky
  • Clinical signs can be delayed 1-5 days after exposure, so a cat may seem normal at first
  • Olive oil, cheese, and nuts can also cause vomiting, diarrhea, and other digestive upset
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Common Questions

What makes pesto bad for cats?
Traditional pesto often contains garlic, and garlic is especially toxic to cats. It can damage red blood cells and lead to anemia. Pesto is also high in fat and may contain dairy or nuts, which can cause stomach upset.
Are cats more sensitive to pesto than dogs?
Yes. Cats are more susceptible than dogs to allium toxicity from ingredients like garlic and onion. That means a cat may be at risk from smaller exposures than a dog.
If basil is non-toxic, can my cat have basil pesto?
No. Basil itself is considered non-toxic to cats, but pesto is not the same as plain basil. Pesto usually includes garlic, oil, cheese, salt, and sometimes nuts, making it unsafe or at least inappropriate for cats.
How much pesto is safe for a cat?
There is no recommended safe serving size of pesto for cats. Because many pesto recipes contain garlic or onion and ingredient amounts vary, pesto should not be intentionally fed.
What symptoms should I watch for after my cat eats pesto?
Watch for vomiting, diarrhea, drooling, poor appetite, lethargy, weakness, pale gums, fast breathing, or dark urine. Some signs of garlic toxicity can be delayed for several days, so keep monitoring and call your vet if you notice any changes.

Sources

  1. People Foods to Avoid Feeding Your Pets — ASPCA
  2. Garlic and Onion (Allium spp) Toxicosis in Animals — Merck Veterinary Manual
  3. Common Cat Hazards — Cornell Feline Health Center
  4. Basil — ASPCA

Disclaimer: The information provided in this article is for educational purposes only and does not constitute veterinary medical advice. Reading this content does not establish a veterinarian-client-patient relationship. Every pet is different — always consult a licensed veterinarian before making decisions about your pet's health, diet, or care. If you'd like personalized guidance, you can talk to one of our vets. If your pet is experiencing a medical emergency, contact your local emergency animal hospital immediately.

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