Pot for Pets?

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.  For more information on CBD and veterinary Cannabis products, please read our previous blog “Marijuana (Cannabis) & Your Pet”.  This blog post will focus on the general aspects of marijuana and how they can affect your pet.

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.

Can I share my Cannabis with my pet?
While there is strong interest in the use of Cannabis derived phytocannabinoids such as CBD for use in pets for chronic pain, severe epilepsy, as well as appetite stimulation, at this time it is not advised to share recreational or prescription human Cannabis products with your pet.  

Cannabis affects both humans and animals through numerous pathways in the body including those found within the Endocannabinoid System (ECS).  The ECS is now thought to be the largest receptor system in the mammalian body and is part of the central and peripheral nervous systems, the endocrine, gastrointestinal, cardiovascular and reproductive systems as well as the skin and eyes.  Dogs in particular are known to have a higher concentration of receptors that are sensitive to Cannabis than any other species studied to date.  This makes dogs much more susceptible to the toxic effects of THC.  

One of the other biggest reasons for not giving your pet Cannabis products at this time, is due to 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.

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 new 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.

What symptoms will my pet show if they have ingested marijuana products?
Symptoms can generally be seen within 30 mins of ingestion and can persist up to 72 hrs. As we discussed earlier, the endocannabinoid system affects several major organs and body systems so the symptoms of toxicity can be broad but most commonly with excess cannabis exposure in pets we will see:
a wobbly gait or stumbling, dilated pupils, salivation, abnormal heart rates, depression or sleepiness, sound or light sensitivity, inappropriate urination, vocalization, lower than normal body temperature, seizures and tremors

It is best to take your pet to your veterinarian as soon as possible if you know they have ingested Cannabis products.  Your pet will require examination and hospitalization for decontamination, monitoring and supportive care, often including IV therapies depending on the timeframe since ingestion and the severity of toxicity.  

Dogs overall tend to be more indiscriminate eaters and are more likely to ingest garbage and scavenge than cats, so we tend to see dietary indiscretion more commonly in this species.  Cats are also generally more selective about their food intake and don’t have as much of a preference for sweets.  Aside from oral ingestion, remember that pets are also at risk for respiratory irritation from second-hand smoke so it is advised that pet owners smoke Cannabis outside and/or away from their pets.  

What do I do if my pet has eaten some of my marijuana?
The veterinarians at Wascana Animal Hospital are primarily concerned for the health and safety of your pet.  If you know that your pet has ingested your marijuana products please tell us!  The quicker we are aware of what has occurred, the faster and more efficiently we can help your pet; saving both time and money.  Unless we are concerned about intentional harm or abuse of an animal, we are more interested in making sure your pet gets the help they need, and will not report this incident otherwise.

Remember that edible products containing your marijuana are also a risk for pets, not only because of the THC content, but also because of additional ingredients which can also be toxic and complicate treatment and response such as chocolate, macadamia nuts, raisins, peanut butter containing xylitol etc. It is important to let your veterinarian know exactly what was consumed! Cannabis products can also cause harmful interactions with other medications that your pet may currently be on and they can also complicate underlying health issues your pet may have.
 
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.

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.