My dog ate flea/tick chews overdose (nexgard, bravecto, simparica) — what should I do?
YELLOW — Call your vet today
What to do now
- Call your regular vet today (or a poison hotline if after hours).
- Watch closely for the symptoms below; if they appear or worsen, go to an emergency vet.
- Remove any remaining material and keep packaging/labels — the vet will want product names and amounts.
- Do not induce vomiting unless a vet or poison-control expert tells you to.
- Note the time it was eaten, roughly how much, and your dog's weight.
Why it's a problem
Isoxazolines have a fairly wide margin; large overdoses may cause tremors or seizures, especially with seizure history.
Symptoms to watch for
Vomiting, tremors, wobbliness, seizures (rare).
When: Hours
Frequently asked questions
Is flea/tick chews overdose (nexgard, bravecto, simparica) dangerous for dogs?
It can be. Isoxazolines have a fairly wide margin; large overdoses may cause tremors or seizures, especially with seizure history. Call your vet today for advice.
What are the symptoms if my dog ate flea/tick chews overdose (nexgard, bravecto, simparica)?
Vomiting, tremors, wobbliness, seizures (rare).
How soon do symptoms appear after a dog eats flea/tick chews overdose (nexgard, bravecto, simparica)?
Hours
What should I do if my dog ate flea/tick chews overdose (nexgard, bravecto, simparica)?
Call your regular vet today (or a poison hotline if after hours). Watch closely for the symptoms below; if they appear or worsen, go to an emergency vet.
Who can I call for help?
ASPCA Animal Poison Control (888) 426-4435 or Pet Poison Helpline (855) 764-7661, both 24/7 (fees may apply), or your nearest emergency vet.
Dose guidance
No reliable dog-specific threshold is published for home use, so any amount should be discussed with your vet or a poison hotline.
Sources
Last verified against these sources: 2026-10-13. Where sources disagree, PawPanic uses the more conservative guidance.
Also known as: nexgard, bravecto, simparica, credelio · Category: Medication · Last reviewed 2026-10-14