The American Society for the Prevention of Cruelty to Animals said things like ibuprofen, acetaminophen, antidepressants and attention deficit hyperactivity disorder medicine were the biggest problems.
The ASPCA advises to always put medications away or pick up pills right away if you drop them.
Vets say many pet owners may not know if an animal has gobbled up a pill, but symptoms like lethargy, vomiting and refusing food can all be warning signs.
About a quarter of the 168,000 calls received by the ASPCA hotline in 2010 were about pets who had swallowed human drugs, said veterinarian Tina Wismer, senior director of veterinary outreach and education at the center.
One aspirin or one heart pill probably won't kill a pet, but a month's supply, a big bunch of grapes, a few bars of dark chocolate or a single lily could.
Insecticides, rodenticides, people food, veterinary medications, chocolate, household toxins, plants, herbicides and outdoor toxins (like antifreeze and fertilizers) round out the top 10.
The Associated Press contributed to this report.