My small dog ate too much Capstar flea medicine. Will she be okay?
It looks like Libby got about 5x the dose she would normally get. Luckily, the toxic dose is quite high for this medication. One study showed that dogs receiving 10x the dose for 14 days showed no outward effects. The lethal dose in rats is about 1000x the dose. Give this, I'd say Libby is rather safe from having a problem.
Look for these signs as a warning for toxicity:
Lethargy/depression, vomiting, itching, decreased appetite, diarrhea, hyperactivity, incoordination, trembling, seizures, panting, allergic reactions including hives, vocalization, salivation, fever, and nervousness.
Please take Libby to the vet immediately if you see any of those signs. Also, if Libby ate the pill within 2 hours, you could take her to the vet and they can induce vomiting - just to be extra safe. If it's been after two hours, then there's no need to make her vomit, so just keep an eye on her.
Overall, I think you have little to worry about.
Updated on September 23rd, 2025