Last October, I took my dog, Mattie, to the Sylvania Veterinary Hospital for the first time for surgery to remove her spleen following a brief illness. I was reluctant, at first, because I would be taking her from her long-time veterinarian, who knew her well, and handing her off to strangers. Yet I was drawn by the hospital's round the clock care.

Following surgery, the prognosis was guarded, but good. Masses on her spleen, which later proved to be cancerous, had not spread. She was alert and standing a few hours later. By 7 p.m., I was told she was not moving, perhaps she was still groggy from the surgery. At 9 p.m., according to her records, Mattie started breathing heavy. Four and a half hours later, she stopped breathing.

A necropsy (autopsy) failed to show a cause of death.

I got a copy of her medical records. I definitely had concerns. Her surgeon, Dr. Ross Mahowald, injected Mattie with acepromazine, a tranquilizer I believe should have been avoided, because it had caused a seizure under another veterinarian’s care. In addition, the vet on call that evening gave Mattie, who had a history of liver disease, Domitor (medetomidine), a potent sedative, after surgery, though the drug is contraindicated in dogs with liver disease. Both conditions were noted throughout Mattie’s medical history, which was submitted to Dr. Robert Esplin, senior veterinarian of the Sylvania Veterinary Hospital, prior to her surgery.

I started doing research on Domitor. The Food and Drug Administration's Center for Veterinary Medicine (CVM) approved the drug as a sedative and analgesic for brief procedures, such as teeth cleaning. It should not be used on dogs with underlying health conditions, such as liver and heart problems, according to its label. Domitor, I learned, is used "extra-label," or in ways unapproved by the FDA, when given after surgery for sedation, and in dogs with certain underlying health conditions, according to the FDA.

Once the FDA approves a drug following rigorous clinical trials to prove its safety and efficacy, health care practitioners can use a drug any way they want.

I called Pfizer Animal Health, which manufactures Domitor, to ask about the contraindications on the label. A product specialist at the company said the drug should be used in healthy, exercise tolerant animals because it slows the heart rate and lowers blood pressure.

"The caution is for it to be used in healthy animals, without a lot of complications," said Dr. Tina Dougherty. "If that is not the case, then vets are advised to go ahead and choose a different, possibly age appropriate product, if it's an older animal - or even a younger animal - that has some underlying medical condition."

Dr. Kirsten Love, the vet on call at the Sylvania Veterinary Hospital, conducted the necropsy. "Everything points to something electrical or with the blood pressure" as a cause of Mattie’s death, she said.

Esplin was stumped.

“We’re still trying to wrap ourselves around why she succumbed, because she shouldn’t have,” Esplin said of Mattie’s death. “I’m confident she could have withstood what we needed to do. The more we’ve talked about it, the less we’ve come to real solid closure as to what happened.”

I wondered if it could have been related to the drugs.

The hospital regularly uses Domitor on dogs for sedation following surgery, according to Love.

“It’s for stress,” she said. “Sometimes they worry, and we like them to settle down after surgery. We do it pretty routinely.”

The CVM does not restrict extra-label use in companion animals. Instead, how a drug is administered or prescribed is left to the judgment of veterinarians.

Still, a drug’s label is “the first source of important facts for veterinarians,” Dr. Victoria Hampshire, former adverse drug events coordinator with the CVM, said in an article published in the Jan. 15, 2004 Journal of American Veterinary Medicine Association (JAVMA).

“The label is the result of considerable scientific regulatory review before CVM approves the drug,” she said. “It represents known safety and efficacy for any one drug. The label also gives veterinarians important information about whether the drug is suitable for the individual or subgroup within a species of animal.”

Had veterinarians at the hospital informed me Mattie would be given acepromazine and Domitor, I would have declined. I don’t believe she was a suitable candidate for either drug. Acepromazine, because of her seizure history, and Domitor, because of its contraindication. Mattie, according to her records, was already on pain medication, one that can enhance Domitor's side effects of slow heart rate and low blood pressure.

Would it have changed the outcome? Perhaps. Maybe not. But I would have liked to have known about the drugs the facility planned on giving Mattie that evening.

Informed consent

At a time when studies show many pet owners consider their pets members of the family, more are becoming actively involved in their health care and want to know the risks of drugs, treatments and surgical procedures. "Informed consent," has become a hot issue.

"With humans, the doctor has an obligation to give you full information and obtain your informed consent before they proceed to do anything," said Prof. David Favre, of the Animal Legal and Historical Center at Michigan State University.

Vets, though, are not, he said.

"How often does this happen? Very seldom," said Favre.

Esplin said he doesn’t inform pet owners about the risks of drugs, treatments and surgeries because “it just never comes up.”

The CVM conducted a two-year review of consumer messages to its adverse drug hotline (). The study found that a majority of calls were made - not by veterinarians - as had been expected, but by the public, Hampshire said in the JAVMA article.

Consumers, in fact, were becoming more involved in their pet's medical care, and increasingly concerned about risks posed by animal drugs, said Hampshire.

Instead of getting important information from their vets, she said, consumers were relying on the Internet to find out about the possible adverse reactions of drugs..

One of the more common complaints from consumers who called the hotline, according to Hampshire, includes the discovery that their pet may have been given a drug for which a precaution or contraindication existed after reading a drug’s Client Information Sheet (CIS) and label on the Internet. A CIS is similar to package inserts pharmacies provide when filling prescriptions that include a drug’s label, warnings, and contraindications.

Legislation

Some states have considered legislation requiring vets to provide informed consent.

In Colorado, a bill was proposed that would have required veterinarians prior to performing or prescribing any veterinary service that involved risks to the life or health of a companion dog or cat to discuss those risks with the owner, as well as any alternative approaches. Vets were exempted if the pet needed immediate care to avoid harm or death. The bill failed to muster enough votes.

Informed consent on extra-label use of drugs is required by the Texas State Board of Veterinary Medical Examiners, which oversees the veterinary profession in Texas.

“If anticipated off-label use of a drug is not commonly accepted or used by average veterinarians in the community in which the veterinarian practices or if the off-label use does not have an established safety record, the veterinarian shall orally or in writing inform the client that the off-label use is not commonly accepted or used in the veterinary community and that it could pose a risk to the health of the animal. Any oral notification shall be recorded in the patient records,” says the rule.

Lee Mathews, general counsel of the board, told The Press the rule was adopted after a complaint was filed against a veterinarian whose extra-label use of a drug caused serious complications in a dog.

“The medication was not specifically labeled for the manner in which it was used,” said Mathews. “The veterinarian was unable to justify the use of the medication except that he had experienced good results in the past.”

Mathews said the rule protects animals against injury and death.

“The public needs to be informed about the relative safety and efficacy of drugs being prescribed to their animals, and the off-label rule forces a veterinarian to consider the relevant factors,” he said.

Jack Advent, executive director of the Ohio Veterinary Medical Association (OVMA), a group that represents the interests of veterinarians, said vets should communicate medical risks to pet owners.

“Veterinarians should assist clients in understanding drugs prescribed to their animal, which includes making them aware of the more common risks that may be associated with that drug,” he said. “Clients should understand that not every possible risk or complication can reasonably be covered for various situations and they should be sure to ask questions about anything they do not understand or need more information about.”

"I think informed consent is a dire necessity," said Laurryn Simpson, who started a website www.dogsadversereactions.com after her dog nearly died from an injection of a long-acting heartworm medication, ProHeart6. The drug was eventually recalled by Fort Dodge Animal Health, the manufacturer, at the request of the FDA, after receiving over 5,000 reports of adverse reactions from the drug over three years.

"Nobody knows our pets like we do," said Simpson, of Commerce Township, Michigan. "We should know risks to drugs our pets will get. Would you allow your child to get drugs that could harm it? I would never have allowed ProHeart6 to be given had I known of its risks. There are still a lot of people that think a dog is just a dog. But many of us think of our dog as our companion, our lifeline."

Features editor Tammy Wilhelm contributed to this report

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