Is Cats Safe?
Is Ivermectin / OTC Dewormers Safe for Cats?
Caution — Ivermectin / OTC Dewormers can be risky for cats.
Ivermectin / OTC Dewormers isn't classed as outright toxic, but it warrants caution around cats — Safe at FDA-approved feline doses, but concentrated equine/bovine pastes overdose easily, and cats with the MDR1 (ABCB1) gene mutation can be poisoned at normal doses. (Separately, NEVER use a dog flea spot-on — see Permethrin.). When in doubt, keep it out of reach and ask your veterinarian.
| Category | Medicine |
|---|---|
| Toxic principle | Safe at FDA-approved feline doses, but concentrated equine/bovine pastes overdose easily, and cats with the MDR1 (ABCB1) gene mutation can be poisoned at normal doses. (Separately, NEVER use a dog flea spot-on — see Permethrin.) |
| Also known as | ivermectin, dewormer, wormer, macrocyclic lactone |
Signs to watch for in cats
- Overdose: wobbliness
- Dilated pupils
- Blindness
- Tremors
- Drooling
- Coma. Use only FDA-approved feline products as directed
- Overdose is an emergency
If your cat may have been exposed to Ivermectin / OTC Dewormers:
- Don't wait for symptoms; don't induce vomiting unless a professional tells you to.
- Note what and how much, and take any packaging with you.
- Call your vet or a 24/7 line now — Pet Poison Helpline 855-764-7661 · ASPCA 888-426-4435.
Cat-safe alternatives
Browse all Medicine for cats · or check another item.
Frequently asked questions
Is Ivermectin / OTC Dewormers safe for cats?
Ivermectin / OTC Dewormers is best treated with caution — it isn't classed as toxic but can cause problems for cats in some forms or amounts.
What are the symptoms if a cat is exposed to Ivermectin / OTC Dewormers?
Reported signs include: Overdose: wobbliness, Dilated pupils, Blindness, Tremors, Drooling, Coma. Use only FDA-approved feline products as directed, Overdose is an emergency.
What makes Ivermectin / OTC Dewormers toxic to cats?
The harmful component reported for Ivermectin / OTC Dewormers is Safe at FDA-approved feline doses, but concentrated equine/bovine pastes overdose easily, and cats with the MDR1 (ABCB1) gene mutation can be poisoned at normal doses. (Separately, NEVER use a dog flea spot-on — see Permethrin.). Cats metabolise many such compounds poorly, so even small exposures can cause problems.
How much Ivermectin / OTC Dewormers is dangerous to cats?
There is no established "safe" amount — sensitivity varies by cat, and small exposures can still cause signs. Treat any exposure as potentially serious rather than waiting to see how much was involved.
What should I do if my cat ate Ivermectin / OTC Dewormers?
Contact your vet or a 24/7 animal poison line right away: Pet Poison Helpline (855-764-7661) or ASPCA Animal Poison Control (888-426-4435).