Marijuana & Your Pet

With the legalization of marijuana this past October, our veterinarians at Wascana Animal Hospital are being asked frequently about the option of using Cannabis for pets.  Marijuana has not only been a popular discussion topic in human medicine lately, but also its potentially beneficial effects for veterinary patients are being touted all over the internet and social media.  One only has to begin typing “pet marijuana” into Google and several anecdotal testimonials from people giving Cannabis products to their pets can be found. CBD oil in particular, has been advertised at many pet stores and online shops and due to its accessibility, is a product we are often asked about.

Cannabis can be divided into three classes:
1. Recreational – plant leaves and/or flowers are smoked, used in baking or other oral formulations by people.  This class of marijuana has the highest risk for pet toxicity as it contains high levels of THC. This class is now legal in Canada when sold through licenced retailers under the Cannabis Act.
2. Medical – this class includes dried & fresh cannabis or oils- these products contain moderate to high levels of CBD and minimal to moderate THC.  This class is available for human use through the Access to Cannabis for Medical Purposes Regulations (ACMPR) and may be prescribed by a medical doctor for people for nausea treatment related to chemotherapy, pain relief, cancer, and epilepsy only to name a few.  While there are many types of phytocannabinoids, cannabidiol (CBD) is the main derivative used in most medical marijuana products.  Some medical marijuana products still contain enough THC to produce toxicity in pets.
3. Hemp – industrial hemp has been traditionally been used for its fibre in textiles and paper.  Hemp is typically used for pet cannabis products most of which are oils, tinctures or powders. Hemp products contain zero to only trace amounts (generally <0.3% or 10ppm) of THC and minimal levels of CBD.

So what exactly is CBD?
CBD is an abbreviation for Cannabidiol, one of many phytocannabinoids extracted from the Cannabis plant.  It lacks the psychotropic effects of THC but potentially contains useful medicinal properties, making it a popular choice for therapeutic use.  Consumers are using CBD products anecdotally for itching, poor appetite, cancers, seizures, arthritis etc.  

So how come I can find pet Cannabis products in stores?
There are some Veterinary Health Products (VHPs) available for animals that have been approved by Health Canada and fall under the Industrial Hemp Regulations (IHR).  These products should have a notification number (NN) that identifies them as having been approved by Health Canada.  If a VHP does not have a NN, its safety and efficacy cannot be verified.  These hemp products include parts of the cannabis plant that are excluded from the Cannabis Act- these are non-viable seed derivatives and stalks containing <10ppm of THC and no isolated or concentrated phytocannabinoids such as CBD.  These VHPs are only for use in cats, dogs and horses that are not intended for food use.  These products are also only for oral and topical routes of administration.  These products are designed to maintain and promote the health of animals and are NOT drugs intended to treat, prevent or cure disease, hence they do not require a prescription.  Products such as hemp seed flour or hemp oil do not contain CBD.  As of March 2018, there were currently 19 approved VHPs available.  Health Canada may request a Certificate of Analysis for any of these products to confirm the levels of phytocannabinoids.  

So why has my veterinarian not recommended CBD for my pet if marijuana is legal now?
Previously, Cannabis and its derivative products (including CBD) were prohibited under the Controlled Drugs and Substances Act Schedule II listing.  With the legalization of Cannabis October 17, 2018, these products are now regulated under the Cannabis Act.  The Cannabis Act includes any part of the Cannabis plant, as well as the phytocannabinoids found in or produced by the plant, regardless of how they are obtained with the exception of those parts of the plant that fall outside of this definition (ex. exempt under the IHR that do not contain phytocannabinoids in significant levels). Health Canada still considers all plant-derived phytocannabinoids (including THC and CBD) as prescription drugs and hence they are included on the Prescription Drug List (PDL).    Therefore even if a product containing CBD was derived from hemp stalks it is still considered prescription.  Under current legislation, CBD from any source that is sold outside of the ACMPR or the Cannabis Act is considered a prescription drug that requires approval from Health Canada and must contain a DIN number.

There are currently not any veterinary cannabis or phytocannabinoid drugs approved by Health Canada for use in animals, hence a veterinarian cannot legally recommend or prescribe one.  That said, with the legalization of Cannabis in Canada, more companies will be developing and seeking approval for the development of veterinary drugs containing Cannabis.  This in turn will increase the push for more clinical research on safety and efficacy. Therefore, in the near future such products may become available for us to prescribe for our animal patients.  Additionally under current Canadian legislation, the only legal way to access medical cannabis is through the ACMPR which applies only to “persons” and cannabis products intended for humans, and are not approved for animal use.  Our national body, the Canadian Veterinary Medical Association (CVMA) is also working with Health Canada to have veterinarians included under the definition of “medical practitioner” in the ACMPR to allow them to have access to medication containing cannabinoids to veterinary patients in the future.  

What do the veterinarians at Wascana Animal Hospital think about CBD pet products?
Being one of few practices in Regina, SK offering integrative veterinary medical therapies (we offer traditional Chinese veterinary medical exams, acupuncture and soon veterinary herbal therapies as well), our veterinarians are open to considering using licensed and approved Cannabis products in our patients in the future and feel such drugs could have merit for appropriate conditions.  There is strong interest in phytocannabinoids for use in painful conditions such as chronic osteoarthritis, for neurological conditions such as drug-resistant epileptics, glaucoma, anxiety, inflammatory skin and bowel diseases, as well as for reducing nausea and stimulating appetite in cancer patients.  

However, besides the need to have approved veterinary Cannabis products that will allow us to prescribe them legally, there are still additional road blocks that need to be overcome. One of the biggest concerns is the lack of research and clinical trials to determine appropriate formulations (oils, capsules, tinctures, transdermal gels), the pharmacokinetics (how the drug is distributed and metabolized in the body), the correct dosages/frequency of dosing, as well as safety and efficacy trials for each species of animal!   We are happy to report that there has been one published study performed so far on dogs looking at the safety and pharmacological aspects of CBD.  However, the fact that there currently is only one, highlights the obvious need for more research and testing. In addition, there are currently no evidence-based clinical studies published stating a recommended dose for either CBD or THC- suggested doses at this time are empirical. There are two clinical trials currently underway at Colorado State University College of Veterinary Medicine where a veterinary neurologist is testing the effects of CBD for epileptic dogs, as well as at Cornell’s College of Veterinary Medicine where they are looking at CBD for treating osteoarthritis. We look forward to seeing the results of these trials in the near future.

In the meantime, our veterinarians wish to caution pet owners who are thinking of giving pet Cannabis products to their four-legged family members, independent of veterinary recommendation, about the risks of doing so.  Due to concerns with toxicity, it is not recommended to share your own Cannabis products with your pets. Also, even though a number of companies are marketing Cannabis products for pets, many of these have not been approved by Health Canada.  As such, these products are unregulated (meaning there is no mandatory inspection of the product or its production) and therefore may vary widely in quality, concentration of the product (despite what the label may say), safety and efficacy.  Veterinarians are always your best source of information and advice for your pet’s health- if you are considering using pet Cannabis products, we recommend a consultation with one of our veterinarians to discuss this topic further and to answer any questions you may have.

Updates as of Oct 30, 2019:

*University of Guelph has a study underway looking at the efficacy of CBD in treating bladder cancer in dogs

*University of Saskatchewan (WCVM) is studying CBD for treating chronic vomiting in dogs and cats as well as looking at CBD and THC safety profiles in cats

Dr. Andrea Ulmer, DVM
Certified Veterinary Acupuncturist (CVA)
November 19, 2018

Sources:
•Government of Canada “Health Products containing cannabis or for use with cannabis: Guidance for the Cannabis Act, the Food and Drugs Act, and related regulations” Oct 31, 2018.
•CVMA “Veterinarians Caution: Medical Cannabis Exposure in Pets”, Oct 3, 2018. Cavanagh, K., Kyes, J., Silcox, S.
•Canadian Association of Veterinary Cannabinoid Medicine “Veterinary Cannabis FAQs”. https://www.cavcm.com.