Rosemary is not poisonous to dogs, according to Anti Gravity Magazine. However, when dogs ingest large amounts of rosemary, it can cause reactions adverse reactions such as upset stomach.
Rosemary is often used to add flavor to dog food. Using it for flavoring does not cause harm to dogs. Typically, dogs do not experience any major issues by consuming a bite or two of rosemary. However, eating several bites of the herb can cause nervous system depression and upset stomach, according to Home Guides. Bog rosemary is harmful to animals. According to Pet Poison Helpline, bog rosemary can cause severe drooling, depression, vomiting, diarrhea and death.