Prescriptions for Healthier Animals : Informed Consent

by Food and Drug Administration (FDA)

(Page 2 of 3)

Much as they do in managing their own health-care, people need to weigh the benefits and risks of a drug prescribed for their pet. It's the veterinarian's responsibility to explain the risks and benefits of each drug to clients, and give them printed information, particularly for the drugs that aren't approved for animal use, says Karen Overall, VMD, Ph.D., professor of behavioral medicine and director of the small animal behavior clinic at the Veterinary School of the University of Pennsylvania. "It's important that we have the informed consent of our clients."

Pet owners should ask their vet questions about any drug being prescribed for their animal — especially in the absence of printed information. Although manufacturers provide a label, or printed information, with each drug they give to veterinarians, says Bataller, "in repackaging the drug at a veterinary facility, the label often does not get passed on to clients. And if the drug is prescribed extralabel, the label would be of limited value to the pet owner."

FDA has helped two animal pharmaceutical companies develop consumer-friendly labels that explain the benefits and risks of their osteoarthritis drugs for dogs. Fort Dodge Animal Health of Overland Park, Kan., distributes a "client information sheet" with EtoGesic (the generic drug etodolac). Pfizer Animal Health, Inc., of Exton, Pa., gives out a client information sheet with Rimadyl (carprofen). Both drugs are non-steroidal anti-inflammatory drugs (NSAIDs).

Pfizer provided the Rimadyl information at CVM's request following a high volume of adverse events, including deaths, reported by owners whose dogs were treated with the drug. The angry owners, who were not properly informed of the drug's risk, prompted the new labeling that will better help other pet owners decide if the drug is appropriate for their dogs.

Although pet owners are becoming better educated and informed about animal treatments, it is still unwise for them to medicate their animals without veterinary supervision, warns Bataller. "Different species metabolize drugs differently. A dog is not a small human, and a cat is not a small dog," he says. "Some drugs may be better tolerated in a dog than in a human, while other drugs may have the reverse effect. Dogs are generally more sensitive to aspirin than humans, and Tylenol (acetaminophen) can readily kill a cat."

A Brave New Behavioral Frontier

"Behavior is an emerging area of vet medicine," notes CVM's Berson, and "improving the quality of life for geriatric pets" is an area of strong veterinary and public interest.

In 1999, the veterinary community and pet owners celebrated the introduction of the first FDA-approved drugs for behavioral conditions in pets: Clomicalm to treat separation anxiety in dogs, and Anipryl to treat the symptoms of canine cognitive dysfunction syndrome (CDS).

Anipryl has the same active ingredient as Eldepryl (selegiline hydrochloride), which FDA approved in 1989 to treat Parkinson's disease in humans.

Clomicalm has the same active ingredient as the human anti-depressant Anafranil (clomipramine hydrochloride), which was approved by FDA in 1989 to treat obsessive-compulsive disorders in humans.

Aging Dogs and Cognitive Decline

FDA first approved Pfizer's Anipryl in 1997 to treat canine Cushing's disease, a common endocrine disorder, and in 1999 approved it to treat canine CDS. This age-related decline of cognitive ability can cause a dog to become disoriented, appear confused or lost in the house or yard, be unresponsive to familiar people, forget previous learned behavior (such as housetraining), bark and whine more, and change its sleep-wake cycle.

"Anipryl really made a difference in my dog's life," says Bobbi Mallace of northern California. Mallace's lively little 10-pound dog, dubbed Miss Piggy because of her pudginess, had a sudden onset of confusion at age 15. "She didn't know what to do with her food," says Mallace, "and she would go under a table and couldn't figure how to get out." After starting on Anipryl, Miss Piggy improved in just three to four days, according to Mallace. "She knew where her food was and how to eat it again. It seemed to clear her head."

Although Mallace was warned by her veterinarian that Anipryl doesn't work in all cases, she calls it a "miracle drug" because it brought her dog's quality of life "almost back to normal."

"[Anipryl] can work a miracle in about one-third of cases, says Nicholas Dodman, BVMS. "It can be useful in about one-third, and it doesn't work in one-third," adds the professor and director of the Behavior Clinic at Tufts University School of Veterinary Medicine.

Some researchers liken the brain of an older animal with CDS to that of an older human. A loss of neurotransmitters has been found in both. And amyloid plaques, or lesions, similar to those that cause damage in the geriatric human brain, have been found in the brains of older dogs and cats. Animal behaviorist Overall says that Anipryl "won't fix the existing plaques, but it will improve the effectiveness of the neurons wrapped up in plaque."

As in diagnosing age-related cognitive decline in people, CDS in dogs should not be diagnosed until all other medical problems have been ruled out. Anipryl cannot cure CDS, but it can alleviate the symptoms and enhance the pet's quality of life.

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.