Frontline, a common flea preventative that disrupts flea neural receptors, is a suspected carcinogen and endocrine disruptor that can be toxic to the nervous system if ingested. It can also cause less serious side effects in dogs, such as irritation at the spot of application, diarrhea, vomiting and seizures.

Can Frontline make your dog sick?

Frontline Plus for dogs is generally safe to use and causes few side effects. Mild skin irritation may occur but should clear up quickly. Additional side effects may include vomiting, diarrhea, and seizure. However, these side effects are extremely rare and tend to affect smaller dogs.

Can I pet my dog after applying Frontline?

Can I handle or stroke my pet after applying FRONTLINE Plus® / FRONTLINE Tri-Act® / FRONTLINE® Spot On? You can handle, stroke and cuddle your pet as usual as soon as the application site is dry. In the meantime treated animals should not be handled and children should not be allowed to play or sleep with them.