Dogs like to eat. However, some foods can be poisonous to dogs. In fact, foods turned out to be the most frequently reported poison dangers for dogs in 2011, according to Pet Poison Helpline, a 24 hour animal-poison-control service. 
The list is based off a study of more than 10,000 cases called into Pet Poison Helpline last year.

1. Foods, specifically chocolate, the sweetener XYLITOL, and grapes and raisins
2. Instecticides, including sprays, bait stations, as well as spot-on flea and tick treatments
3. Rodenticides (mouse and rat poison)
4. Nonsteroidal anti-inflammatory drugs (NSAIDS) for humans, such as ibuprofen and naproxen
5. Household cleaners, such as sprays, detergents and polishes
6. Antidepressant human drugs, such as PROZAC, PAXIL, CELEXA, EFFEXOR
7. Fertilizers, including bone meal, blood meal and iron-based products
8. Acetaminophen human drugs, such as TYLENOL an d cold medications
9. Amphetamine human drugs, such as ADDERALL and CONCERTA (medications that are used to treat attention deficit disorder and attention deicit hyperactivity disorder)
10. Veterinary pain relievers, specifically COX-2 inhibitors like RIMADYL, DERMAXX, PREVICOX

A description of each item listed can be found on Pet Poison Helpline's website (www.petpoisonhelpline.com)