Why is my dog vomiting, lethargic, and not eating after flea meds?
Hello. It sounds like Charlie was given Capstar & Bravecto. However, if they were administered on the 28th, the Capstar was out of his system after 24 hours. Vomiting & loss of appetite are the 2 most common signs of the Bravecto, but it is still an extremely safe medication. So I am not sure we can blame it on the flea medications after this much time. If the vomiting has just started, withhold all food for at least 8-12 hours, & only allow small amounts of water, preferably as ice cubes. Restart food using 25% cooked chicken & 75% white rice when the vomiting has stopped. Give very small meals frequently rather than 1 or 2 big meals. If Charley seems comfortable, transition back to his regular diet after about 1 day or so. If the vomiting continues, or he shows any signs of fever, belly pain or diarrhea please see your veterinarian. Thanks for using Petco Pet Education Center, formerly Petcoach.
Updated on September 23rd, 2025