Veterinary marijuana?

With pet owners already using the drug as medicine, veterinarians need to join the debate
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Human hands holding marijuana buds
Photo by R. Scott Nolen

Miles was dying.

The 12-year-old black Labrador Retriever–type dog had developed a splenic tumor that eventually metastasized to the liver and lungs. Miles was given two months to live and tramadol for the pain.

But, Miles’ owner didn’t like the way tramadol affected her pet. “Every time we gave it to him, he would just sleep; he wouldn’t even move. He’d just lay there like he was dead,” said Denise, who asked that her real name not be used.

Sitting outside a West Hollywood, Calif., café with Miles at her feet, Denise recalls how a friend suggested she try a glycerin tincture of marijuana that is sold as a pet medicine in dozens of licensed medical marijuana dispensaries throughout Los Angeles. Within an hour after she gave Miles the tincture, the dog’s appetite returned, and he was no longer vomiting. “It couldn’t have been a coincidence,” Denise said.

Denise says marijuana has improved Miles’ quality of life since the dog developed terminal cancer. (Photo by R. Scott Nolen)

“The other great thing is that in the last couple of weeks, Miles has been going to the beach, he’s been running, he’s being himself,” she continued. “If Miles was on the tramadol, he’d be in bed, and he wouldn’t be enjoying anything or eating anything, and he’d probably be dead. I’m just really grateful we found this.”

Though initially hesitant about giving her pet an unapproved drug, Denise figured where’s the harm? Miles has terminal cancer and would die soon. Besides, people can’t overdose on marijuana, she reasoned. “I wasn’t that worried. I was actually pretty excited, because it has been used with human cancer patients for pain and nausea,” Denise said.

If the tramadol had worked, Denise says she wouldn’t have considered giving her dog marijuana. Now a “true believer” in marijuana’s therapeutic effects for at least some animal ailments, Denise says she will recommend the drug to other pet owners. “People need to understand that this isn’t about getting my dog high,” she said. “It’s about improving his quality of life.”

People need to understand that this isn’t about getting my dog high. It’s about improving his quality of life.

Denise, a pet owner who turned to marijuana to help her dog, dying of cancer

The times, they are a-changin’

States have been chipping away at the federal prohibition on medical marijuana since 1996, when California voters approved a referendum allowing patients to receive a doctor’s recommendation to grow or possess marijuana for personal use. Nineteen states and the District of Columbia have since passed similar laws permitting marijuana to be used medicinally in people. And in 2012, Colorado and Washington state legalized recreational marijuana use.

The federal government, however, has not followed suit. Federal law currently prohibits all uses of marijuana, and anyone violating the law faces serious legal penalties. Even in those states where medical marijuana use has been approved, officers with the federal Drug Enforcement Administration periodically raid medical marijuana dispensaries, seizing their assets and shutting them down, even if only temporarily.

U.S. map
States where medical marijuana is legal

Differences in state and federal marijuana laws aside, public attitudes about the drug are in flux. In April, the Pew Research Center reported that, for the first time in four decades, most Americans (52 percent) favor legalizing marijuana. In addition, 77 percent of those surveyed said marijuana has legitimate medical uses. Such sentiment is notable, given the Food and Drug Administration’s position that marijuana is neither safe nor efficacious for treating any human or animal disease.

Scheduling conflict

Marijuana has been classified as a schedule I controlled substance since 1970. Schedule I is the most restrictive of the federal Controlled Substances Act categories and is reserved for drugs with no currently accepted medical uses and a high potential for abuse. Heroin, LSD, and ecstasy are schedule I drugs, for example, while cocaine, methamphetamine, and morphine are schedule II drugs.

Scientists have identified more than 60 chemicals, or cannabinoids, unique to marijuana. Although whole marijuana is not approved by the FDA for any medical use, cannabinoid-based drugs are available by prescription in the United States. Nabilone is a synthetic cannabinoid used as an antiemetic and adjunct analgesic for neuropathic pain. It is also approved for the treatment of anorexia and weight loss in AIDS patients.

The regulatory hurdles for clinical research on schedule I drugs are so high as to act as a deterrent. Numerous physician and health care organizations, including the American Medical Association, American Public Health Association, and National Association for Public Health Policy, are urging the federal government to reschedule marijuana to allow more research that could yield new cannabinoid-based medications.

If it’s good enough for me

Denise is probably not typical of the millions of U.S. pet owners. She is part of what is likely a small community who use marijuana for their pets because they see it as a safe, natural, and effective alternative to “man-made” drugs. Should legal and social prohibitions associated with marijuana use continue easing, more and more pet owners might come around to this line of thinking, and Denise’s views could one day be less unorthodox than they are now.

Ernest Misko and Borzo
After marijuana relieved Ernest Misko’s back pain, he started feeding the drug to his geriatric pet cat Borzo when the animal had difficulties walking. Within a few days, Borzo was walking normally again. (Photo by R. Scott Nolen)

Ernest Misko had never experimented with marijuana until his doctor recommended the 77-year-old Chatsworth, Calif., resident try it for his chronic back pain. Misko was so amazed with how good his back felt afterward that when his aged pet cat, Borzo, had difficulty walking, Misko started feeding the cat the same marijuana tincture Denise used. Within a few days, Borzo appeared to be pain-free and was moving much better, according to Misko.

“I don’t get high from (marijuana), but the pain goes away. So I tried it on my cat, my 24-year-old cat, who’s feeling better,” Misko said.

Becky Flowers came to believe in marijuana’s healing powers for animals in a similar fashion. The Southern Californian’s pet horse, a 20-year-old Paso Fino named Phoenix, had had degenerative ligament disease for several years. But nearly a year ago, the condition worsened. Phenylbutazone, glucosamine, Cavallo boots, cold and warm wraps—whatever Flowers tried, it didn’t help the horse for long. Eventually, Phoenix lay on her side and stopped eating and drinking.

Before resorting to euthanizing Phoenix, Flowers fed the horse marijuana. After all, Flowers herself had found marijuana to be a more effective analgesic than the medication she had been prescribed for pain associated with spinal spurs, arthritis, and several recent wrist surgeries. “Cannabis offers more relief to me than Norco, so why wouldn’t it also help Phoenix?” she reasoned.

Phoenix’s degenerative ligament disease had stopped responding to conventional therapies, and the horse was no longer walking, eating, or drinking. Before resorting to euthanasia, Becky Flowers fed her horse a small amount of marijuana. Phoenix’s condition quickly improved, according to Flowers, who says the horse is “doing incredible.” (Courtesy of Becky Flowers)

Within an hour of ingesting a small amount of marijuana, Phoenix was walking, eating, and drinking, according to Flowers. She boils the marijuana plant, then makes the abstract into a butter that she feeds the horse once a day.

“With cannabis, I don’t worry about potential liver damage as with bute. I also don’t worry about her overdosing, as I only give her a small amount. She never appears panicky or disoriented. She’s just her normal, happy Phoenix,” she said, adding that her Chinese Crested dog Tripper no longer chews on his feet since Flowers started mixing a small amount of marijuana into the dog’s food once a day.

The crusader

Since 2011, some 300 people have told Dr. Douglas Kramer about having experimented with medical marijuana for a pet. Prior to that, Dr. Kramer had worked at a small animal practice in California, where clients would occasionally admit to giving marijuana to an animal companion for a medical reason. He now runs his own mobile practice in the Los Angeles area focused exclusively on pain management and palliative and hospice care.

Dr. Kramer didn’t think much of marijuana's potential to help animals until his pet Siberian Husky developed terminal cancer.

“Nikita was wasting away, and she’d stopped eating,” he recalled. “I’d exhausted every available pharmaceutical pain option, even steroids. At that point, it was a quality of life issue, and I felt like I’d try anything to ease her suffering.” Dr. Kramer began feeding Nikita a small amount of marijuana. The dog’s appetite returned, and she appeared more comfortable during her final months.

Dr. Kramer
Dr. Douglas Kramer, shown here in a West Hollywood, Calif., medical marijuana dispensary, is convinced of the plant’s potential as a veterinary drug. He says veterinarians should advocate for less-restrictive regulations on marijuana research, possibly leading to new cannabinoid-based medications for animals. (Photo by R. Scott Nolen)

My position is the same as the (American Medical Association's). We need to investigate marijuana further to determine whether the case reports I’m hearing are true or whether there’s a placebo effect at work.

Dr. Douglas Kramer, an advocate for marijuana’s potential as a veterinary therapy

Now, Dr. Kramer finds himself at the forefront of an effort to bring veterinary medicine into the national debate about medical marijuana. On the basis of his review of medical marijuana research, Dr. Kramer believes there’s ample evidence to support using marijuana in veterinary patients as an alternative or adjunctive treatment for postoperative or chronic pain and also for palliative care.

“I don’t want to come across as being overly in favor of giving marijuana to pets,” Dr. Kramer noted. “My position is the same as the AMA’s. We need to investigate marijuana further to determine whether the case reports I’m hearing are true or whether there’s a placebo effect at work. We also need to know what the risks are.”

Pet owners aren’t waiting on the science, however. Dr. Kramer’s survey shows they’re feeding marijuana to pets to treat behavior-based disorders, including separation anxiety and noise phobia, as well as irritable bowel syndrome and feline immunodeficiency virus infection; for management of pain, nausea, and seizures; and as an appetite stimulate. Cannabis oil is also being used topically to treat tumors.

Physicians in states where medical marijuana is sanctioned are exempt from prosecution by the state for recommending the schedule I drug to patients. Such protections do not apply to veterinarians, for whom it is illegal in every state to prescribe or recommend marijuana to treat a patient.

Dr. Kramer sympathizes with veterinarians leery of openly considering marijuana’s potential as a veterinary drug. Besides the social stigma the drug carries, the only experience most veterinarians have with pets and marijuana is being presented with patients that have ingested toxic amounts of the drug. Nevertheless, Dr. Kramer is frustrated that so many of his colleagues haven’t been more engaged in an area with real and potential animal welfare impacts.

“The veterinary community needs to address the issue, but we don’t want to talk about it, even though it’s clear our clients are giving marijuana to their pets, with good and bad effects,” he said.

Some may dismiss Dr. Kramer’s views as a product of his culturally and politically liberal West Coast environment, but he isn’t alone. For several years, Dr. Brown (not his real name) has practiced at a small animal hospital in Ohio. Many of his patients are geriatric pets or cancer patients. Even before the medical marijuana movement commenced in the 1990s, clients were asking about giving marijuana to their sick pets, according to Dr. Brown.

“I caution that I cannot legally give them advice about marijuana, and they understand that. We can talk about the situations in which people use it,” he said. No client, he added, has ever brought up marijuana while conventional treatment options were still available.

Like his California colleague, Dr. Brown is frustrated by the predominant view among veterinarians that marijuana is only a toxic plant. “There is no distinction made that there are many, many strains of cannabis, each with their own potential medicinal properties based on their cannabinoid profile,” he said. “Some of the newer strains that seem to have less-intoxicating properties and higher pain-relieving properties may be very useful in animals.”

My gut reaction is they do probably provide some therapeutic effect benefit. But I’m never going to say there’s enough benefit that marijuana should be given to pets. I’m saying there’s enough justification that we need to study it.

Dr. Dawn Boothe, Clinical Pharmacology Laboratory director, Auburn University College of Veterinary Medicine

Toxic effects

Dr. Dawn Boothe wouldn’t be surprised if veterinarians are one day treating patients with FDA-approved analgesics made from cannabinoid derivatives.

“My gut reaction is they do probably provide some therapeutic effect benefit,” said Dr. Boothe, director of the Clinical Pharmacology Laboratory at Auburn University’s College of Veterinary Medicine and a diplomate of the American College of Veterinary Internal Medicine and the American College of Veterinary Clinical Pharmacology. “But,” she quickly added, “I’m never going to say there’s enough benefit that marijuana should be given to pets. I’m saying there’s enough justification that we need to study it.”

Dr. Boothe thinks veterinarians shouldn’t discount marijuana’s potential as an animal therapy simply because it’s a controlled substance or a plant; after all, the same can be said about morphine. Whereas morphine’s pharmacological effects on humans and animals have been thoroughly studied, Dr. Boothe said that’s not the case for marijuana, which is why giving the drug to a pet as medicine is actually putting the animal at risk.

The public shouldn’t assume marijuana affects humans and animals in the same ways, nor should they assume, that because marijuana is a natural substance, it isn’t harmful. “When people say something is natural and therefore safe, my immediate response: ‘Natural to what?’” Dr. Boothe said. “Marijuana certainly doesn’t occur naturally in animals or people, and that’s why the body develops ways of ridding itself of compounds introduced to it.”

Dr. Boothe referred to a study from a 2012 issue of the Journal of Veterinary Emergency and Critical Care that found the number of marijuana toxicosis cases at two Colorado veterinary hospitals quadrupled during a five-year period when the number of state medical marijuana registrations substantially increased. Researchers reported two dogs died after eating baked goods containing marijuana.

The chances of this trend being unique to Colorado are remote, according to Dr. Boothe, who sees this as one more reason the veterinary profession can no longer sit on the sidelines as the rest of the country debates medical marijuana.

“Veterinarians do need to be part of the dialogue. We should be kept in the loop in terms of translational medicine aspects,” she said. “I can see a well-designed, controlled clinical trial looking at the use of marijuana to treat cancer pain in animals. That would be a wonderful translational study, with relevance to both pets and their people.”