Veterinarians Look to Cannabis for Pets, but Challenges Abound

Dr. Quetzalli Hernánadez, the veterinarian in charge of Nidia's care at a wildlife park in Mexico, was desperate. Nidia, an Asian elephant, suffered from chronic foot problems and her pain had caused her to lose her appetite and lose weight. Determined to help Nidia, Dr. Hernandez turned to cannabidiol, or CBD, the nonintoxicating therapeutic compound found in cannabis.

While medical cannabis for humans is legal and commonly used in several countries and U.S. states, its adoption in veterinary practices has been much slower. But a small but growing number of international veterinarians are working to change that through education, research and activism.

Cannabis contains dozens of chemical compounds, but CBD and tetrahydrocannabinol (THC) are the molecules whose therapeutic effects are best understood. While CBD does not discernibly alter consciousness, THC is responsible for the "high" associated with smoking or ingesting marijuana.

Dr. Stephanie McGrath, a veterinary neurologist at Colorado State University who studies medical cannabis and is on the scientific advisory board of Panacea Life Sciences, a CBD product manufacturer, said, "People are very interested in alternative therapies that work better and have fewer side effects."

But despite the promising findings, challenges abound for introducing cannabis into veterinary medicine, including confusion about the law, lingering drug-related stigma, a lack of education and a dearth of peer-reviewed studies. In most countries, including the United States, prohibitive or incomplete legislation also hampers veterinarians' abilities to study and use cannabis in their practices.

Laws in places like California have begun to make way for veterinary cannabis, and a small but growing number of international veterinarians have united to bring cannabis into mainstream veterinary medicine through education, research and activism. Dr. Castillo and his colleagues have trained around 1,500 veterinarians in Mexico alone on medical cannabis use since 2019.

Ideally, veterinarians and pet owners work together through trial and error to determine the best regimen for the animal. "Cannabis medicine is more challenging for me than oncology is, because in oncology there is a protocol to follow," said Dr. Trina Hazzah, a veterinary integrative oncologist and co-founder and president of the Veterinary Cannabis Society, an advocacy and education group in California. "Cannabis is so personalized."

While most veterinarians focus on cannabis for pets, those in Colombia, Dr. Castillo said, have taken the lead on using it for zoo animals. Dr. Diana Buitrago, a veterinarian at the Cali Zoo, estimates that she and her colleagues have given cannabis to more than 50 species, from mountain tapirs and lions to snakes and capybaras. They have found that CBD works well for pain, inflammation, osteoarthritis, and allergies, and that it can also enhance the effectiveness of treatments for conditions such as cancer.