Hermosa Veterinary Clinic Animal Articles

Featured Article:
Bad Medicine
by Erin Harty

   The 18th century Venetian adventurer, romancer, and alchemist Giovanni Casanova reportedly said, "In the hands of the wise, poison is medicine. In the hands of a fool, medicine is poison."

   And in the hands of a pet owner who isn’t careful, the wrong kind of medicine can have disastrous consequences.

   Advancements in medicine over the last several decades have given us a cornucopia of drugs that can help cure or alleviate many ills, both in humans and in animals. But what’s good for the goose is definitely not always good for the German shepherd. A medication that works for you may not work for your dog, and what works for your dog may not work for your cat, rabbit, or ferret.

   "People think that cats are like little dogs, and they’re all like little people. They don’t think about it, and they don’t read the [medication’s] label," said Dr. Petra Volmer, assistant professor of toxicology at the University of Illinois College of Veterinary Medicine. "Someone thinks, ‘I use naproxen and it works great for my back. My dog has a sore leg, so let’s give him some naproxen.’"

   Animals of different species process drugs in widely varying ways. Dogs, for example, are very sensitive to non-steroidal anti-inflammatory drugs (NSAIDs) that are common in their humans’ medicine cabinets. This class of drugs includes pain medications like acetylsalicylic acid (aspirin), ibuprofen (Advil and Nuprin), acetaminophen (Tylenol), phenylbutazone ("bute," a common painkiller for horses) and naproxen.

   According to pet poisoning guidelines issued by the American Veterinary Medical Association, as little as two tablets of regular strength aspirin or Tylenol can cause significant tissue damage in dogs, and repeated doses significantly increase the risk of death.

   Cats are even more sensitive to NSAIDs because they have less of the enzyme that is required to detoxify and utilize the drugs: just two extra-strength Tylenol can be deadly. NSAID metabolites can impair the function of a cat’s red blood cells, which carry oxygen from the lungs to all the cells of the body. If the red blood cells aren’t performing their job properly, a cat can suffocate from lack of oxygen.

   Well-meaning owners often assume that these common, over-the-counter drugs are safe for their pets in smaller doses. "It has nothing to do with size; it’s the way they metabolize it. With everything, we assume that cats are twice as sensitive," said Jill Richardson, DVM, veterinary poison information specialist at the American Society for the Prevention of Cruelty to Animals’ National Animal Poison Control Center.

   The problems aren’t limited to human medications—a drug that may be safe and useful for one animal can be deadly for another. Many of the calls to the National Animal Poison Control Center are regarding accidental poisonings from topical flea medications. Products that are designed for dogs often contain a drug called permethrin, which has a wide safety range when used on Fido. But just a few drops of the product may cause Fluffy the cat to suffer potentially fatal seizures.

   Rabbits are also extraordinarily sensitive to flea medications intended for both dogs and cats. The Frontline brand in particular has been blamed for several rabbit deaths, although the manufacturer has never suggested that the product be used on rabbits.

   "Drugs in rabbits are very different from dogs and cats. Extremely different, in some cases," said George Flentke, a biochemist in the toxicology department at the University of Wisconsin. "I always recommend that people contact a bunny-savvy vet [before using any medication.] They keep up on this stuff."

   Although the packaging for any such products will explicitly say that they’re only for use on the species for which they’re intended, owners sometimes mix up medications that are meant for other pets. Or they simply won’t read the label, and will (erroneously) assume that a product can be used on any animal.

   "Think about what you’re doing. Animals are different from people, and different from each other. All different species metabolize things differently," said Dr. Volmer. "If you’re not sure [if a medication is safe], call your vet or ask an animal poison control center."

   In some cases, pets get themselves into poisoning trouble. Dogs may dig discarded medication out of the trash, or chew up an entire box of cold medicine, contents and all. Cats may lick the sugar coating off tablets of Advil that are left on the side of the sink. A ferret with run of the house might get into a kitchen cabinet and help itself to some Prozac.

   Large breeds of dogs are the most frequent mass-consumers of medications. "They’re less finicky. They don’t think, they just eat," said Dr. Volmer. "And they don’t stop at one [tablet]. They have to eat the whole package."

   Ferrets also seem prone to overdose accidents because they’re extremely curious and have the appetites of dogs, according to Dr. Richardson. Cats, on the other hand, won’t usually eat something unless it tastes good; their overdoses are most often human-caused.

   According to guidelines issued by the National Animal Poison Control Center, all prescription and over-the-counter drugs should be kept safely out of pets’ reach, preferably in closed cabinets. Pain killers, cold medicines, anti-cancer drugs, antidepressants, vitamins and diet pills can all be lethal to animals.

   Also beware of herbal medications, Dr. Richardson warns. Just because something is billed as "natural" doesn’t mean it won’t have adverse affects on a pet. One particular herbal diet aid has caused numerous accidental poisonings.

   "It contains mahuang, which is like herbal ephedrine, and guarana, which is like caffeine. We’ve had so many horrible cases on that," said Dr. Richardson. She recently treated a miniature pincher who’d eaten 30 to 50 of the pills. A lethal dose of this drug is 6 milligrams per kilogram of body weight; the pinscher consumed 7 times that, and eventually died.

   In most cases, animals have a good chance of survival if their owners seek medical attention immediately. A veterinarian can pump the animal’s stomach, administer activated charcoal and perform diuresis, all of which will help minimize the dangerous effects of the drug. The sooner a veterinarian sees a pet, the more likely the case will have a happy ending.

   "We do have some ‘miracle cases.’ But not very many of them would have made it if someone hesitated or waited a day or two," said Dr. Richardson. "I think in most cases we get here, if we get the information early, the animals are treated promptly and appropriately."