Cannabinoid products have grown in popularity with pet owners over the past decade, given the advances in research, product availability, and a shift in public paradigm. Currently, there are many products available both for human and veterinary use, but there is often confusion about what the products actually contain, how they work, and what they can effectively treat. This is a rapidly evolving subject, but what does the science actually tell us?
Let’s start with some basic cannabinoid terminology and understanding.
What is a Cannabinoid?
Cannabis sativa is the scientific name of the cannabis plant which has been used by human civilization for thousands and thousands of years. Different parts of the plant have been utilized for specific purposes, whether it be for cloth, paper, food, medicine, etc. Both Hemp and Marijuana are different strains of the Cannabis sativa. Cannabis sativa is considered hemp when it contains less than 0.03% delta 9-tetrahydrocannabinol (THC).
Marijuana plant strains are members of the cannabis sativa family that contain greater than 0.03% THC. THC is a psychoactive cannabinoid and can be toxic in dogs. Cannabidiol (CBD), on the other hand, does not have a psychoactive effect, can counteract THC’s psychoactive effects, and appears well-tolerated in dogs and cats.
A cannabinoid is a molecule that binds receptors within the endocannabinoid system (ECS), which is present in every vertebrate animal and plays an important role in homeostatic regulation (balance within the body). Endocannabinoids are cannabinoids created within an animal’s own body, while phytocannabinoids are plant-derived molecules such as THC and CBD. The receptors for the ECS are found throughout the body which is one reason cannabinoid research is such an exciting and promising field. Dogs have a very high percentage of a particular ECS receptor within their brain which is what makes them susceptible to the toxic effects of THC.
Additionally, it’s well known in veterinary medicine that different species have varying responses to drugs, and CBD products are no different. Veterinary researchers at institutions such as Cornell, Colorado State University (CSU), the University of Pennsylvania, the University of Florida, and Auburn University are exploring the safety and potential uses for species-specific, veterinary-targeted CBD products.
So what are the potential veterinary uses of CBD products?
- Osteoarthritis: Studies at Cornell and CSU support the use of specific CBD products to increase the comfort and activity of dogs with osteoarthritis.
- Seizures: A pilot study out of CSU showed promise for the use of CBD to reduce the frequency of seizures in dogs even though the goal of 50% reduction was not definitively achieved. A long-term study at CSU, and a similar study at the University of Florida, are currently underway to determine if a different dosage may have a more beneficial effect.
- Anxiety: ElleVet Sciences, a CBD company, recently released a study where 20 out of 24 dogs had a decrease in stress or anxiety-related behaviors when given ElleVet Calm and Comfort chews. There are other studies currently underway in both cats and dogs which may further clarify the potential use of CBD products for these species.
- Dermatological: Studies indicate an alteration in ECS receptors in canine allergic skin disease and feline hypersensitivity dermatitis. This exciting discovery suggests a potential target for CBD product use in these patients.
- Degenerative myelopathy: While research is ongoing, there is evidence that CBD supplements may help protect the nervous system in dogs with this devastating disease.
- Cancer: Although studies in dogs are currently in progress, promising oncological studies on cell cultures revealed CBD-inducing apoptosis (cellular death) in canine osteosarcoma, mammary carcinoma, lymphoma, and glioblastoma cells.
- Gastrointestinal: ECS receptors have also been found in the gastrointestinal tracts of dogs and cats which suggests a potential target for CBD products.
Sounds great, but are there any downsides to CBD?
Potential drug interactions: When giving CBD products with other sedating medications, pets may experience more profound sedation, a decreased appetite, and altered behavior. In the case of benzodiazepines, such as valium, dogs may even show symptoms similar to THC intoxication. Finally, there is a theoretical risk of serotonin syndrome (a life-threatening drug reaction) when used in combination with SSRIs such as trazodone.
Potential side effects: CBD products have so far appeared to be very safe for our canine and feline pets. However, in some safety studies, patients exhibited an increase in one liver value (ALP). No other liver value alterations were noted, and none of these animals required intervention (treatment). It is recommended that pets who are on long-term CBD products should have their liver values monitored routinely. Other side effects noted in studies include mild diarrhea, ocular or nasal discharge, and redness of the ears, although some of these side effects may be from the carrier and not the CBD itself.
Which is the best CBD product for pets?
There are a multitude of CBD products that advertise in pet and human markets, so choosing one can be overwhelming. The first step is to find a product with a peer-reviewed safety and efficacy study that can back up their claims, but it’s important to note that a study for one product does not necessarily mean that another similar product will have the same results.
There are also products in the human market with a high level of CBD, but these are not the best choice for our canine friends since they may still contain enough THC to result in toxicity symptoms (which include: lethargy, depression, incoordination, changes in heart rate, changes in respiratory rate, altered body temperature, dilated pupils, a startle response, incoordination, urinary incontinence, and in severe cases, seizures.) In addition, some human products may contain other substances that are toxic to our dogs, such as chocolate and xylitol. Therefore, the best option for a CBD supplement would be a canine or feline-specific product that has a safety and efficacy study to back up their claims.
The FDA does not regulate the production of CBD supplements, so care must be taken to ensure you are getting a quality product.
At a minimum, look for products that have obtained a Certificate of Analysis, perform safety testing, provide full ingredient lists, and follow Good Manufacturing Practices (GMP) or have a National Animal Supplement Council (NASC) Quality Seal. Finally, a study out of CSU revealed that CBD-infused oil has the most promising pharmacokinetic (drug absorption) profile when compared to capsule and transdermal formulations. Therefore, oil formulations may be preferred over others.
What you need to know
Preliminary studies support the use of certain CBD products for pets, particularly for pain relief in osteoarthritis, seizure relief, and anxiety relief, while research is promising for CBD use for allergic skin disease, degenerative myelopathy, gastrointestinal disease, and cancer patients. However, before administering a CBD product to your pet, care must be taken to choose a veterinary-specific product that has been carefully studied to support its claims. Be sure to speak with your veterinarian before starting your pet on any CBD products.
By Melissa Turner, DVM, CVA, and Eric N. Glass, MS, DVM, DACVIM (Neurology)