My dog ate a spider killed by bug spray. He's fine, should I worry?

In general, most over the counter pesticides when dry, will not harm pets. The most common signs seen will be some transient vomiting, possible drooling, and possibly diarrhea when ingested in small amounts. Obviously there are many different kinds of pesticides available and the signs associated with them can vary greatly. The label on the original container for the pesticide should have a phone number to contact incase of concerns and more specific guidance may be found there.

Ingestion of dead spiders is not likely to lead to any significant illness. As your dog is reportedly fine, it is unlikely you will see any problems at this time. Of course, if you notice your dog acting ill, please seek veterinary attention.