FRIDAY, Aug. 13 (HealthDay News) -- When John D'Amato arrived home early from work one day, he found an empty bottle of ibuprofen on the living room floor -- and one very sick pet.

His Great Dane puppy, Otis, had knocked the pain-reliever container off the coffee table -- where D'Amato had left it the night before -- and devoured dozens of the pills.

"My heart dropped through the floor," he said of the discovery.

D'Amato rushed the 85-pound puppy to a veterinary clinic near his home in Manchester, N.H., where the staff immediately induced vomiting and began administering IV fluids. Had D'Amato arrived home much later, Otis might not have survived.

Ingestion of over-the-counter and prescription drugs formulated for humans are by far the most common cause of pet poisonings in this country, veterinarians say.

Since the ASPCA's Animal Poison Control Center (APCC) in Urbana, Ill., began keeping statistics in 2002, human medications have consistently topped its annual list of the most toxic substances pets ingest.

Of the 98,000 calls received so far this year, about one-third involve dogs and cats consuming human medications, says Camille DeClementi, a veterinary toxicologist with APCC.

Non-steroidal anti-inflammatories, such as Advil, Aleve and Motrin, are among the top offenders, the APCC finds. Other drugs commonly eaten by dogs and some felines include antidepressants (Prozac), acetaminophen (Tylenol), anti-anxiety drugs (Xanax), sleep aids (Ambien) and beta-blocker blood pressure medications (Tenormin or Toprol.)

"The most toxic things in our homes are the medications we take," she said. "Animals are inquisitive, and get into things they're not supposed to."

Pets knock vials off countertops and nightstands, or owners mistakenly think they're helping their pets by giving them human medication to alleviate some sort of ailment.

That's a big no-no.

"Dogs' and cats' metabolisms are different from ours, so they can't always process the same drugs we can," explains Silene Young, a former emergency room veterinarian who works for Veterinary Pet Insurance (VPI) in Brea, Calif.

Just one extra-strength Tylenol, for example, can kill a cat. And the anti-cancer topical treatment, Fluorouracil, can be fatal in dogs, even in the tiniest doses ingested -- say, from chewing on the discarded cotton swabs used to apply the cream, according to veterinary toxicologists.

Medication mix-ups cause unintentional poisonings too. By grabbing the wrong bottle, some owners inadvertently give their pet medication that's really meant for them or other humans.

Keeping animal and human medications in separate drawers or cabinets is the simplest way to prevent those types of mishaps from occurring.

It's also a good idea, veterinarians say, for owners to take their medication in the bathroom with the door shut. That way, if a pill drops on the floor, they have time to retrieve it before the dog does.

Luckily, a good portion of pet poisoning cases are treatable at home if caught right away, says the DeClementi. The center runs a 24-7 hotline staffed by veterinary toxicologists who give diagnostic and treatment recommendations for poison-related emergencies in animals.

And if a trip to the veterinary hospital is warranted, you'd better take along your credit card. Treating a pet that has ingested a human medication costs owners, on average, $791 before insurance reimbursement, according to VPI.

As for Otis, the Great Dane, he pulled through just fine after three days of intravenous fluids and close monitoring by veterinarians.

The sheer number of pills he gobbled -- at least 35 -- could have caused gastric ulcers or kidney failure, both of which can cause death.

Quick action taken by his owner, though, saved the young dog's life and stopped internal damage from developing. "He's been back for check-ups since [the incident]," says D'Amato, "and he's a very healthy dog."

More information

For first aid tips involving pets, see the American Veterinary Medical Association.