Medical Marijuana in People and Pets: History, Controversy, and the Future

Bucky, a 16-year-old Queensland heeler, had been athletic until a leg injury, hip dysplasia, and arthritis conspired to limit his mobility. Bucky’s owner, Sand Brim, discussed her concerns with her veterinarian, Gary Richter, MS, DVM, CVA, CVC, who talked about the potential benefits of medical marijuana.

Brim, an attorney in Oakland, California, purchased an oil containing a 1:1 ratio of the cannabinoids tetrahydrocannabinol (THC) and cannabidiol (CBD) from a local dispensary and began putting it in Bucky’s food. “I saw an immediate difference,” she reports. “He wasn’t running around like a puppy, but he was walking more easily and I could see that he was in less pain and had a little bit more energy.”

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Brim is one of a growing number of pet owners who have turned to cannabis to treat their ailing pets. And despite the plant’s federal classification as a Schedule 1 drug, more and more veterinarians are also expressing interest, say advocates.

“I speak regularly to groups of both pet owners and veterinarians, and I’ve never had a veterinarian say, ‘Absolutely not! Marijuana is evil and I don’t want to have anything to do with it,’” observes Dr. Richter, who owns Holistic Veterinary Care and Rehabilitation Center and Montclair Veterinary Hospital, both in Oakland. “Most say they are interested and want to know more.”

Ancient History, Current Roadblocks

In 1996, via Proposition 215, California became the first state to legalize medical marijuana, but the plant actually has a very long history as a medicinal compound. “In terms of medical use, it goes back at least 10,000 years,” reports Jahan Marcu, PhD, chief science officer with Americans for Safe Access, a national organization established in 2002 to ensure safe and legal access to cannabis for therapeutic use and research. “There is documented ancient use around the world for pain relief and the treatment of various conditions.”

Until the 1930s, inexpensive cannabis-derived tinctures were readily available through physicians and pharmacies in the United States and were used to treat ailments ranging from arthritis to seizures to menstrual cramps. However, cannabis fell out of general use with the passage of the 1937 Marijuana Stamp Act, which added a dollar to every dose, and the plant became illegal in 1970 with the passage of the Controlled Substances Act, which placed marijuana in the same classification as heroin and methamphetamine. Cannabis is widely used today to treat numerous conditions, including amyotrophic lateral sclerosis (Lou Gehrig’s disease), chronic pain, anorexia due to HIV/AIDS, Crohn’s disease, seizures, glaucoma, Tourette’s syndrome, multiple sclerosis, and nausea and vomiting associated with cancer treatment. According to Dr. Marcu, however, there is little consistency among states regarding what conditions cannabis can and cannot be recommended for. In California and Washington, DC, for example, doctors are free to make their own decisions, whereas other states have very specific guidelines. State laws “run the gamut from treating cannabis like regular medicine to treating it like it’s radioactive,” Dr. Marcu says.

The Drug Enforcement Agency (DEA) and Food and Drug Administration make it very difficult for researchers in the United States to study marijuana’s potential medicinal qualities effectively, Dr. Marcu notes. However, there is hope for change through the Compassionate Access, Research Expansion, and Respect States (CARES) Act, which has bipartisan support in both the House and Senate. As of this writing, the legislation was still in committee. In addition, Americans for Safe Access is suing the DEA to update the information on its website, some of which is 40 years old, Dr. Marcu says.

Support, Skepticism, and Entrepreneurship

Eight states and the District of Columbia currently permit the adult recreational use of marijuana, and 28 states have approved the medicinal use of marijuana for humans. The patchwork of laws, however, hasn’t stopped veterinarians with an interest in alternative medicine from discussing the benefits of cannabis to relieve anxiety, pain, seizures, gastrointestinal problems, and other ailments in dogs and cats, as well as other species. As a result of this surging interest, marijuana entrepreneurs—many of them veterinarians—have developed a variety of medicinal cannabis products specifically for animals.

Stephen Katz, DVM, owner of Bronx Veterinary Center in the Bronx, New York, is one such practitioner. He is one of the founders of Therabis, an herbal formula containing CBD—a nonpsychoactive cannabinoid derived from industrial hemp—that he recommends for mobility problems, anxiety, and itching. “I had been working with natural anti-inflammatories for 15 years,” Dr. Katz says. “I started looking at cannabis and CBD about 6 years ago and decided to turn my scientific mind toward using it in an effective, medicinal way to benefit my clients’ pets.”

Sarah Brandon, DVM, witnessed the medicinal properties of marijuana 20 years ago when her husband, Greg Copas, also a veterinarian, started smoking it to ease injury-related joint pain. Based on his success, they began giving marijuana to their Rottweiler, Reilly, to ease the pain of his hip dysplasia, with similarly positive results. More research followed, and in 2014 Drs. Brandon and Copas co-founded Canna Companion, a company based in Washington State that manufactures 2 whole-plant hemp products for dogs and cats.

Eager to educate the next generation of practitioners, Dr. Brandon recently gave a talk to veterinary students at Colorado State University and found them receptive to the idea of medical cannabis for pets. “They were open-minded but not to the point of blindly accepting it,” Dr. Brandon notes. “They were doing their due diligence.”

Pet owners are often skeptical as well. When Dr. Katz suggested to his client Yamahyra Lopez that she give Therabis to her pitbull-Rottweiler mix to treat his mobility issues, Lopez was unsure but decided she had nothing to lose. “It was like a miracle,” Lopez reports. “Within 2 weeks Lil Jeff started greeting us at the door like he used to. He was running again, and so engaged. We were thrilled.”

Anecdotal evidence like this abounds, yet most veterinarians remain reluctant to recommend cannabis to their clients for several reasons. Foremost is the fact that marijuana and hemp are still considered controlled substances by the DEA, which means it is illegal for veterinarians to prescribe them for pets. “We can, however, discuss the benefits of medical cannabis with pet owners and provide them guidance regarding what the best products would be for their pet and what a successful dosing regimen would look like,” notes Dr. Richter, who had such a discussion with Sand Brim.

Indeed, the issue of legality must be resolved before medical marijuana for pets can go mainstream, says Dawn Boothe, DVM, PhD, professor of anatomy, physiology and pharmacology at the Auburn University College of Veterinary Medicine and director of the college’s Clinical Pharmacology Laboratory. “For veterinarians to get on board, it’s going to take knowing they won’t be prosecuted for having products containing cannabis in their clinics or for promoting their use,” she explains. “Right now, that’s a big problem. As soon as that’s fixed, most veterinarians won’t hesitate to recommend cannabis products, in part because the products are incredibly safe.”

Equally concerning to many veterinarians is the lack of peer-reviewed clinical studies proving the efficacy of cannabis products for animals, another consequence of marijuana’s status as a controlled substance. However, that is slowly changing. The University of Pennsylvania School of Veterinary Medicine will soon begin controlled, double-blind studies on Dr. Katz’s Therabis line, and the Auburn University College of Veterinary Medicine has developed an assay to detect cannabinoids in the blood of dogs, cats, and horses in an effort to determine appropriate dosing. “It is our intent over the next couple of years to start doing randomized, controlled clinical trials,” Dr. Boothe says. “We will focus on epilepsy as well as the control of pain associated with lameness in dogs and cats.”

Where Do We Go From Here?

The American Veterinary Medical Association (AVMA) has no formal position regarding the veterinary use of medical marijuana but does agree that more studies are needed, says Sharon Granskog, the AVMA director of media relations. Its human equivalent, the American Medical Association, holds a similar position and has urged the National Institutes of Health to implement administrative procedures to facilitate grant applications and the conduct of clinical research into the medical utility of marijuana. It has also urged that cannabis be reclassified on the federal level.

Many veterinarians aren’t waiting. Dr. Richter, for example, has become a vocal advocate and encourages his colleagues to look deeper into what cannabis has to offer. “To my peers I would say, there is an enormous amount of research out there proving the benefits of medical cannabis if you take the time to look for it,” he says. “What you will find is an enormously effective medicine that very few people are using and very few pets are benefitting from. We as medical professionals have the power to change that.”

Don Vaughan is a freelance writer based in Raleigh, North Carolina. His work has appeared in Military Officer, Boys’ Life, Writer’s Digest, MAD, and other publications.