Animals and Cannabis

The use of cannabis for animal species is an area of growing interest, largely due to the therapeutic benefits being observed for humans and animals in the era of cannabis legalization. The close relationship that humans have with their pets and other veterinary species has led to a renewed interest in the possibility and promise of cannabis to treat similar issues that humans are using it for.

Endocannabinology Foundation has been using cannabis oil to treat pets and captive wild animals for seizures, anxiety, arthritis, and pain. We hope to continue working with animal organizations to provide natural healthcare to alleviate suffering of wild animals in captivity. A6T Foundation also donates cannabis oil to animal rescue organizations to treat formerly mistreated circus and zoo animals.

2. Pain relief and Arthritis

One of the most common reasons people look into cannabis for pets is to treat pain, whether it’s caused by an on-going condition like arthritis or a temporary condition like an injury. Cannabis products at the right dose, can kill pain and reduce inflammation not causing kidney issues, as many other painkillers do. For some pets, it can present a safer and more tolerable pain management option than traditional pharmaceutical pet medications.

Arthritis is a condition that causes chronic inflammation and pain in the joints. It is caused by the degeneration of cartilage, which causes the bones in the affected joint to rub against each other.

Feline arthritis will affect a cat’s ability to run, jump, or even walk. Many people, even vets, think that feline arthritis isn’t very common. However, studies have shown that up to 60% of cats over the age of 6 have arthritis in at least 1 joint. The same research also showed that cats over 14 years old have an 80% chance of dealing with arthritis.

Dog osteoarthritis or dog joint pain can be an extreme annoyance to the point of dogs not wanting to move at all due to the issue. Just like humans with arthritis, dogs can suffer from their joints aching all the time. Cannabis products are a great option for any dog with joint pain and arthritis. A study from Cornell University concluded that regular doses of “cannabis products increase comfort and activity in the home environment for dogs with osteoarthritis. Additionally, veterinary assessments of pain were also favourable.” More than 80 per cent of dogs showed an increase in mobility and physical comfort.

4. Appetite Loss/Nausea

Over the years, cannabis has become well-known as a natural anti-nausea treatment – particularly for patients who are undergoing chemotherapy. It also works well for animals who have lost interest in food or who are experiencing digestive problems. In addition to calming nausea, it also stimulates appetite, which is a double benefit to cats that have lost weight due to a continued bout of vomiting.

6. Cancer

Cannabis can be useful both in the treatment of cancer, and for the many symptoms that accompany conventional cancer treatments. It has been shown to kill certain cancer cells and stop the growth of blood vessels to tumours. CBD may also have antioxidant properties and can help slow down tumour progression. In addition, new studies suggest that CBD may help chemotherapy work more efficiently in animals with cancer.

The CBD component is not the only part of the cannabis plant that may be useful for fighting cancer. Hemp extract is also rich in other natural compounds, such as terpenes and flavonoids. Limonene, a terpene found in hemp, has been shown to have anti-cancer properties. Flavonoids, such as luteolin and kaempferol, are found in hemp and have been shown to cause disruption to cancer cells. When selecting a CBD product for your dog or cat, look for a full spectrum or broad spectrum hemp extract, since these extract contain these other natural compounds.

Here are four ways that cannabis can support animal cancer patients:

a. Stimulates appetite It can be difficult to keep your dog or cat eating when he has cancer; as well, many types of cancers cause weight loss. Maintaining body mass can be crucial for the longevity of your animal, yet the symptoms of cancer combined with the side effects of some medications can cause nausea and low appetite. It was previously thought that THC provided most of the appetite stimulation associated with the cannabis plant (consider the “munchies” that people get when using marijuana). But full spectrum hemp extract that’s rich in CBD can also help decrease nausea and increase appetite.
b. Helps treat tumours (when applied topically) CBD may offer benefits when applied directly to tumours. Studies have shown that it can kill certain types of cancer cells. Cannabis extract may also speed wound healing while decreasing pain, which may be beneficial for skin tumours that become open wounds. While there are no current studies investigating the topical treatment of cancer in dogs and cats, there is no known harm in applying hemp extract to tumours.
c. Manages pain Cancer pain can be severe, especially when the tumours are associated with bone. CBD has been shown to decrease pain and inflammation. It should not be used on its own for pain management, but it can be added to a more traditional drug regimen. While more studies are required, there have been no reports of adverse interactions between CBD and other drugs when treating pain in dogs and cats. Higher doses of CBD (2 mg/kg to 3 mg/kg twice daily) may be warranted to help manage cancer pain.
d. Can reduce side effects of chemo and radiation A few studies suggest that the use of CBD during chemotherapy and radiation may help reduce side effects and even have a synergistic effect. However, more studies are needed to confirm this benefit for dogs and cats.

Before using CBD with your animal, whether or not he has cancer, discuss it with your veterinarian, and be sure to do some independent research online and find a high-quality hemp-derived product formulated for dogs and cats. Using the right product in the right way (see section on administration), can help treat cancer in companion animals, while alleviating symptoms and treatment side effects.

7. Wild Animals

Some wild animals might be a nuisance to outdoor cannabis growers: for instance, deer, when they are left with nothing else, they will leave no plants untouched. Rabbits and raccoons have been spotted nibbling on cannabis plants when food options are limited. Rats and mice will use the plants for gnawing purposes. Burrowing mammals like gophers and moles have been known to eat cannabis roots, while rodents and birds will eat the seeds.

Among captive wild animals, it has been observed that a snake with a cancerous tumour achieved an 80% reduction in the tumour after 7 weeks of treatment with CBD oil. Another anecdotal report comes from a zoo who has seen a 95% reduction in the seizures of a goat treated with CBD oil. Also, a tiger with cancer is using CBD oil to alleviate pain and discomfort, as well as stimulate appetite.

8. How to administer?

The route of administration is a primary contributing factor in the effectiveness of any medicine, natural or otherwise. Choosing the appropriate delivery method for the patient can greatly affect medical outcomes. In pharmacology, bioavailability is the fraction (%) of an administered drug that reaches the systemic circulation depending on the route of administration. The associated bioavailability of the drug should be balanced with the practical needs of the patient.

There are several formats of cannabis products for companion animals, currently in the marketplace, and several up-and-coming formats currently undergoing research and development efforts by forward-thinking companies.

a. Oral Route of AdministrationIngested route is very common and still quite effective, in spite of its poor bioavailability. Pharmacokinetic (pK) studies documenting the bioavailability of oral cannabis extracts, specifically the major cannabinoids THC and CBD in both humans and dogs, demonstrate that only 5–10% of the lipophilic drug (compounds that dissolve in lipids rather than water) reaches its intended active site. In spite of this relatively poor bioavailability, good clinical responses have been documented in both species.
- a1- Capsules — Capsules contain a fixed volume of active materials and are limited in efficacy to specific weight ranges of patients. This limitation necessitates manufacturing and packaging multiple capsule sizes to accommodate the many different sizes of veterinary species, Chihuahua to Great Dane to draft horse. Capsules are convenient to keep and administer and are a dosage-form that is familiar to most consumers.
- a2- Tinctures — These are oil infusions of lipophilic extracts of the cannabis plant and can contain either high THC cannabis (“ marijuana”) or low THC cannabis (“ hemp”). Carrier oils can be any oil, but most commonly grape seed oil, hemp seed oil, and olive oil are used in these formulations. Tinctures have the advantage of being scalable in terms of being able to dose different sizes of animals, since all that is needed for a larger or smaller patient would be more or less volume, respectively. Tinctures can also be added or mixed with a small amount of tasty food to facilitate administration but are most efficiently absorbed transmucosally (diffusion through a mucous membrane) from the oral cavity.
- a3- Dosage -form animal health products —Dosage-form treats need to have the intent, and be labelled, as nutraceuticals, not as nutritional compounds.
  - i) Hard biscuits and soft-chews currently are the most popular dosage-form treats available in the marketplace due to the relative ease of their administration. Like capsules, these products can contain only a fixed amount of the active ingredients, thus limiting the weight ranges addressed by a single dosage-form treat size. The potential disadvantages could be patient hypersensitivity to the ingredients in the treat, the need for multiple treats at a time to treat a larger weight patient, the reduced shelf life, and the potential that the manufacturing process that involves baking or heating could cause active ingredients to be less effective.
  - ii) Pellets are pressed from dried cannabis plant material, most commonly using the low THC cannabis variety (“hemp”). These pellets can be given to horses, goats, sheep, and other farm animals, as well as poultry, swine, zoo animals, caged birds, and pocket pets. Pellets are scalable for dosing a wide variety of target species weights.
  - iii) Powders can be contained in wide-mouthed bottles with a measuring scoop in them that can be used to estimate effective dosages. Powders can be packaged into stand up pouches, as well as sticks, sachets, and, of course, capsules, which are more convenient for dosing but remove the scalability benefit of powder over dosage-form treats.
  - iv) Transmucosal routes of administration, meaning diffusion through a mucous membrane, like snorting, or sublingual (under the tongue). It can be very effective in most contexts, as it is fairly easy to apply the liquid cannabinoids to the oral mucous membranes. This approach is a good bioavailable administration approach.
b- Topical and Transdermal Administration
- b1- Topical applications of cannabinoids have low systemic bioavailability but will penetrate locally to benefit the regional anatomy. Products that are in solvents like alcohol or use emulsifiers to create a water-soluble cream or lotion have a better chance of penetrating the hair or feathers and ultimately penetrating the skin. These are termed “liniments” if they contain alcohol and “creams” or “lotions” if they are emulsified and water-soluble.
- b2- Transdermal applications involve the use of a bipolar material such as a phospholipid to carry the cannabinoids into the local circulation and from that enter the systemic circulation. Transdermals can be creams or can be in “patches” that use a membrane to separate the transdermal solution from the skin. For veterinary species, transdermal liquids and patches will need to have a spot of hair clipped prior to application. Transdermal medication absorption is dependent upon the amount of local vascularity to carry the medication from the skin into the systemic circulation.
c- Inhalation Inhalation is an impractical delivery method for veterinary species, except maybe primates or laboratory animals connected to breathing masks. As water-soluble versions of cannabinoids are developed, the possibility exists that a nebulization method could be employed to allow for absorption through the large surface area of the lungs. Inhalation methods are rapid onset and bypass first pass metabolism in the liver.

9. Is cannabis dangerous for my pet?

Any sort of cannabis consumption requires a certain level of education and responsibility, and this also applies to cannabis and pets. Experts advise pet owners to communicate clearly with their doctors before starting any regimen of medical marijuana for pets; this will help ensure that any positive results or adverse reactions are closely monitored. Education about accidental marijuana consumption and THC toxicity in pets will also help reduce the explosion in calls to pet poison control centres. All cannabis products should be stored away from pets to prevent accidental consumption.

Despite a mounting body of anecdotal evidence, there is still relatively little research on the effects and toxicity of cannabinoids, like THC and CBD, on animals. It should be noted there are no reported deaths that can be definitively attributed to THC or other phytocannabinoids without other factoring chemicals also present in the system. The suspected lethal dose of THC in dogs is >9 g/kg, a nearly impossible dose to achieve.

The most common route of exposure to THC in companion animals is via ingestion. Approximately 66% of exposure involve pets ingesting homemade or commercial edible goods. The second most common source of cannabis exposures involves ingestion of plant material, followed by ingestion of cannabis oils or tinctures.

Symptoms of THC intoxication include lethargy, central nervous system depression, ataxia (lack of voluntary coordination of muscle movements), vomiting, urinary incontinence or dribbling, increased sensitivity to motion or sound, dilated pupils, hypersalivation, and bradycardia.

10. Traditional vets vs cannabis vets

The endocannabinoid system (ECS) has been evolving since the beginning of vertebrate species, but why did veterinary practitioners never learn about it in school?

Veterinary medicine has historically lagged behind human medicine since its inception. Veterinarians and veterinary technicians are cautious creatures that often have not only a human as the owner to deal with but a patient that cannot speak and tell you how treatment is or isn’t working. We also see less uniformity in regulations and practice acts in veterinary medicine compared to our human counterparts.

What veterinary medicine and human medicine do have in common is the lack of education on the topic of cannabis as a legitimate medical therapy in veterinary school. We also see less interest in pharmaceutical companies wanting to invest in clinical studies for companion animals (cats and dogs). Moreover, we see more conservative organized veterinary medicine, like the American Veterinary Medical Association, still holding on to out-dated information and prohibition era beliefs surrounding cannabis, perpetuating false assertions that there is no evidence for safety or efficacy of cannabis products in animals.

The use and demand for cannabis products in veterinary medicine is growing rapidly, mainly by pet owner demand. Unfortunately, it is growing faster than most practitioners have the time to educate themselves about it. As veterinarians and veterinary scientists better understand this fascinating and emerging therapy, they shall be able to better deploy cannabinoid therapies for their animal patients and formulate more effective cannabinoid medications.