Cannabis: The Use of Cannabinoids in Veterinary Medicine

Controlled scientific evidence regarding cannabis-derived products remains limited in animal studies, although their potential is increasingly recognized. The Federation of European Veterinarians (FVE) encourages the conduct of clinical trials before assessing their therapeutic value and safety for pets, and seeks to establish national legislation to promote the marketing of high-quality, safe products with tested and validated efficacy. The use of cannabis and cannabis-derived products is growing worldwide. In North America and Europe, several countries have already adopted more lenient legislation, authorizing the medical—and even recreational—use of cannabis. Consequently, the availability of cannabis-derived products for humans has had an impact on their pets. In particular, veterinarians are seeing an increasing number of cases of toxicity in animals, while also having to meet growing demand from animal owners for these types of products, especially to relieve their pets’ pain. But before using cannabinoids in animals—beyond the legal considerations—it is important to understand the indications, side effects, and efficacy of this type of treatment. Although certain cannabinoids, such as cannabidiol (CBD), appear to show promising therapeutic results for treating osteoarthritis pain, immune-mediated and inflammatory allergic disorders, epilepsy, and pain in general—including cancer-related and neuropathic pain—the available controlled scientific evidence regarding their use in animals remains limited. There are few clinical studies, and most are anecdotal or based on case reports. No cannabis-derived product has yet been authorized as a veterinary medicinal product in Europe, with a few rare exceptions (homeopathy and feed supplements). However, it is important to keep in mind that cannabis-derived products available on the EU market are rarely regulated or properly labeled. Many brands market cannabis-derived nutritional supplements or care products for dogs, cats, or horses, whose therapeutic claims (for anxiety, loss of appetite, etc.) are unfounded. These products do not comply with European legislation, and their labeling is unreliable. The identity, quantity, and quality of the ingredients and pharmacologically active substances vary from batch to batch, making dosage and dosing regimens very difficult, if not impossible. These products are not subject to any regulation and, in most cases, to no independent quality control. They may therefore contain high levels of tetrahydrocannabinol (THC) or other substances with toxicity, such as terpenoids. Only the composition of medical cannabis is known and controlled. In response to the proliferation of unregulated products, the Federation of European Veterinarians (FVE) encourages an increase in controlled scientific and clinical studies to evaluate the potential therapeutic effects and safety of cannabis-derived products for pets. Furthermore, national—or even European—legislation should be enacted to encourage the marketing of high-quality products whose safety and efficacy have been tested, monitored, and validated. Pending the publication of such studies on the use of cannabinoid-based products in animals—and particularly on their safety—the FVE recommends that these products be available only by veterinary prescription.