Cannabis use–whether it’s hemp or marijuana-derived cannabidiol (CBD) or medical marijuana—is a gray area when it comes to pets.

The question comes down to federal law versus state rights in many cases, and there is a significant lack of research on animal uses. Federally, the U.S. Drug Enforcement Agency (DEA) lists cannabis and cannabinoid products—under which CBD products fall—as Schedule I controlled substances, and the U.S. Food and Drug Administration (FDA) has warned consumers about purchasing cannabinoid-containing products sold widely across the country and over the Internet.

Only one cannabinoid-containing medication—used to treat pediatric seizures—has been approved by FDA, and only hemp products have been descheduled under the 2018 Farm Bill. Despite these federal rules, however, many states have moved forward with their own laws on recreation and medicinal marijuana, as well as CBD products.

While the American Veterinary Medical Association (AVMA) cautions that state laws legalizing cannabis and CBD products for human use do not apply to animals, few states have issued any guidance specific to use of these products in animals.

As these products become more widely available to humans, veterinarians have increasingly faced interest from pet owners about CBD and cannabis products, but AVMA says there is little valid research on the benefits and risks of cannabinoids in animals. AVMA officials acknowledge that there have been limited studies, anecdotal reports, and case studies about therapeutic benefits in pets, and they note that more well-controlled research is needed to make evidence-based recommendations to veterinarians and pet owners. There is also a lot of uncertainty about the products available, whether they are derived from hemp or marijuana, and what concentrations of THC—the psychoactive component of cannabinoids—they contain. This uncertainty adds to concerns about cannabis toxicity, most often observed so far in dogs who were exposed to their pet owners’ cannabis-containing edibles.

At an FDA hearing on food and dietary supplements containing cannabis products in May 2019, Ashley Morgan, DVM, director of the AVMA State Advocacy Division, spoke on behalf of AVMA and said that while there might be therapeutic benefits for pets from cannabis products, there needs to be a clearer regulatory process for products coming to market, and that more research of efficacy and safety are needed. Morgan told dvm360 that the legal landscape for cannabinoid products for pets right now is “extremely complicated.”

“If you can confirm that the CBD product did indeed come from industrial hemp (legal federally under the 2018 Farm Bill), that’s one thing. But right now there’s no good way to do that,” Morgan said. “The product that is currently available is being shipped from state to state.”

Currently, veterinarians are at risk even discussing CBD or cannabis products with pet owners, as veterinary licenses are evaluated at both the state and federal levels. This applies to discussions not only about therapy, but also toxicity.

Gail Golab, DVM, PhD, chief veterinary officer of Scientific Affairs and Public Policy at AVMA, noted that there is some progress being made on the research front, but there only a small number of national studies taking place.

“There just isn’t the research. There’s not a lot of research in the veterinary space out there in total, and there’s even less in the way of studies that have been conducted that are well-designed,” Golab said.

Much of the research, she said, is completely observational, relying on a client’s impression of efficacy, and the veterinarian’s perspective. There has been little objective work done, and Golab cautioned that the placebo effect of cannabis-containing products can be as high as 40%.

Although exactly how cannabis laws aimed at humans applies to pets may be unclear, it can be assumed that pet owners who can purchase CBD in their state for their own use may also decide to use those products on their pets. Golab said with the popularity of cannabinoid-containing products on the human front, there is concern that pet owners may also choose them for their pets over other therapeutic agents with demonstrated efficacy, leading to therapeutic failures as well as potential adverse effective.

Components of cannabis can interfere with some medications and therapies, and veterinarians should exercise caution when pet owners express interest in these products both for the sake of the pets and the veterinarian’s own liability, according to Golab and Morgan.

AVMA officials do not want to discount the potential benefit of cannabis products for pets, Golab said, but there is a lot to consider pending better data.

“The therapeutic potential may be there, we just need to really understand what they do,” Golab noted. “I think the best thing veterinarians can probably do is provide the information and education to their clients. Clients also need to understand the issues with quality control around these products.”

Golab added there are a few companies currently researching animal-specific cannabinoid products and seeking FDA approval, and she believes these endeavors will yield useful data.

To learn how each state is approaching cannabis products, and whether they have addressed animal use, follow the map: