New tricks for old dogs

By Kimberly Kirchner, Herbalist Contributor

American pet owners are spectacularly big spenders. The American Pet Products Association reports that consumers spent over $72.5 billion on their animal companions in 2018, and predicts 2019 totals will surpass $75 billion. If that doesn't impress you, consider that the National Retail Federation estimates Americans forked over $480 million last year just for their pets’ Halloween costumes.

With that kind of money on the table, it’s no surprise that cannabis producers have expanded into the pet supply market. Sales of cannabis products for pets quadrupled in the last two years — going from $8 million in 2017 to $32 million in 2018 — according to industry research firm Brightfield Group.

But while sales surge ahead, actual medical research proceeds at a slow trickle, held back by the same legal uncertainty that has complicated medical marijuana research for humans. Owners interested in cannabis treatments for their pets face a maze of regulatory and scientific questions.

First, the good news

Is veterinary cannabis worth all this confusion? Early research says “yes.”

The endocannabinoid system — the network of receptors that interact with cannabinoids like THC and CBD — is common to all vertebrates, with a similar function across species. Proponents suggest that some of the positive results seen in human cannabis users can be replicated in companion animals.

The most well-known scientific study of veterinary cannabis, published this June in the Journal of the American Veterinary Medical Association, builds on CBD’s status as an FDA-approved epilepsy treatment to address the condition in dogs. Researchers at Colorado State University performed a double-blind, placebo-controlled study on 16 epileptic dogs, and found that nearly 90% of the dogs receiving CBD oil saw a decrease in seizures, compared to just 20% of the dogs receiving the placebo. While small, the study heightened interest in veterinary cannabis and prompted the American Kennel Club’s Canine Health Foundation to sponsor an expanded version of the study, testing the same product on a larger pool of participants over a three-year period.

A clinical study at Cornell University assessed comfort and activity levels of dogs with osteoarthritis, with and without twice-daily doses of CBD oil. Participants received four weeks of CBD treatment and four weeks of a placebo, in random order. Dogs showed noticeable improvement to their OA symptoms while receiving CBD oil, and researchers concluded that there was enough evidence to warrant a larger-scale study in the future.

Participants in both studies suffered no serious side effects, indicating that, as in humans, CBD may be a safer alternative to more traditional drugs.

The descheduling of hemp in the 2018 Farm Bill (more on that shortly) jump-started medical research into CBD. A flurry of new studies, many of them sponsored by major veterinary cannabis distributors like ElleVet and VetCS, are currently in progress. The studies cover a wide range of species and ailments, including epilepsy, cancer and postsurgical pain in dogs; pain and anxiety in cats; arthritis and laminitis in horses; and a viral gastrointestinal disease in birds.

Legal complications

The laws concerning veterinary cannabis, particularly CBD, are murky at best, and flat-out contradictory at worst. The 2018 Farm Bill took a step towards clarity by defining hemp (cannabis containing less than 0.3% of the psychoactive chemical THC) as distinct from marijuana, which remains a Schedule 1 controlled substance.

This lifts federal restrictions on products made with hemp, but individual states are still free to impose their own restrictions. The Massachusetts Department of Agricultural Resources issued a formal policy statement this June explicitly banning the use of hemp-derived CBD in food products, including dietary supplements, animal feed and any product making therapeutic or medicinal claims.

In addition, the Federal Food and Drug Administration continues to classify hemp-derived CBD as a drug, and requires CBD products to undergo the same review process as any other medication. To date, only one CBDbased medicine has earned the FDA’s approval. The FDA also prohibits the use of CBD as an additive in food, drinks or dietary supplements. As a result, CBD products currently on the market have not been inspected by the FDA for safety and quality, raising concerns about contamination and mislabeling.

To further complicate things, medical marijuana laws apply only to human patients; they grant doctors the right to prescribe cannabis for medical use, but do not explicitly expand that right to veterinarians. The result is a legal gray area that leaves animal health practitioners unsure of how and when they can discuss cannabis with their clients.

In 2018, California legislature approved a bill granting legal protection to veterinarians who discuss veterinary cannabis products with their clients; in New York, a similar bill is under review by the Senate Health Committee. The California law stops short of allowing vets to make specific product recommendations, however, and the state’s Veterinary Medical Board has yet to publish formal guidelines for talking to clients about cannabis.

The majority of state veterinary associations have no written policy for cannabis use on animals, regardless of the state’s laws on human cannabis consumption. A study published in the January 2019 issue of Frontiers in Veterinary Science found that less than 22% of veterinarians polled felt that their state veterinary organization “has provided sufficient guidance for me to practice within the state or federal laws” when it comes to cannabis.

In March, the Boston Globe reported that the Massachusetts Veterinary Medical Association was preparing an advisory assuring vets that talking about cannabis for patients was legal, though treatments should be approached with extreme caution due to the lack of research and oversight. As of late June, the organization had not made any public statements on the matter.

At least one major veterinary organization has come forward with a definitive statement on discussing cannabis treatment options. The Colorado Veterinary Medical Association, in a position statement adopted in 2016, asserts that while it is illegal for veterinarians to prescribe marijuana products for animal use, “veterinarians have an obligation to provide companion animal owners with complete education in regard to the potential risks and benefits of marijuana products in animals.”

CBD in practice

Regardless of where they stand on the legality of CBD for pets, animal health experts agree that pet owners should consult their veterinarian before beginning any kind of cannabis treatment.

Veterinary Cannabis Education and Consulting, a veterinarian-run group dedicated to educating owners and practitioners on the ins and outs of cannabis use, encourages pet owners to be upfront about their interest in or use of CBD treatment options. Like all drugs, CBD has the potential to interact negatively with other medications, so it’s important to consult a medical professional before diving into a new treatment. Pet owners should also discuss possible risks and withdrawal symptoms before discontinuing any current medications. CBD may be available without a prescription, but it should be treated with the same care and caution and as any other medication.

Since CBD pet products are not FDA-inspected, owners must take it upon themselves to ensure what they’re buying is safe and accurately labeled. One way to go about this is to ask for a Certificate of Analysis (COA) for every product before purchase. The COA indicates that the product was tested by an independent third party, and details the amount and concentration of any cannabinoids present. It also analyses the product for heavy metals, toxic chemicals and bacteria, so owners can be sure the product is free of any harmful substances. Veterinary Cannabis suggests owners bring the COA and product packaging to their vet for a review if they’d like extra assurance.

When it comes to administering CBD, the common wisdom is “start low and go slow.” The Cornell osteoarthritis study identified 2 mg/kg as a safe starting dose. Owners can then gradually increase the dosage, if needed, until the desired result is achieved. Veterinary Cannabis recommends keeping a journal of the pet’s activity over the course of treatment to spot any gradual changes, good or bad.

Tinctures (liquid cannabis products) are the most widely recommended form of cannabis for animals, since they allow for precise dosing and have been subjected to the most clinical research so far. Tinctures should be oil-based, not alcohol-based. CO2 and alcohol are considered the safest extraction method for pets; butane or propane extraction can leave behind dangerous residue. Edibles designed for human consumption may contain ingredients that are toxic to animals and should not be administered to pets.

Products containing THC are best avoided — at least for now — as legal restrictions have prevented any in-depth studies on prolonged use in animals.

There’s a lot of ground left to cover when it comes to making veterinary cannabis safe and readily available to all patients. But if Americans put half as much effort into policy reform and clinical research as they do into doggie birthday parties and Instagram accounts for their cats, change won’t be far away.

When things go wrong

Unfortunately, not all animal cannabis use is owner-sanctioned. The American Society for the Prevention of Cruelty to Animal’s Poison Control Center reported more than 1,800 calls about pets consuming marijuana products in 2018, a 765% increase since 2008.

The good news is that marijuana consumption alone is almost never fatal. While THC is toxic to animals in large doses, it’s virtually impossible for one pet to consume enough product to cause lasting damage. On its website, the American Veterinary Medical Association notes that “several deaths have been reported due to Cannabis toxicity, and these appear to be the result of associated complications, such as aspiration.”

Marijuana edibles, however, often contain ingredients that are dangerous and even potentially fatal to pets. Chocolate, raisins and particularly the sweetener xylitol can drastically decrease chances of recovery. Regardless of the form in which it was consumed, any signs of cannabis poisoning warrant an emergency trip to the vet.

Signs of cannabis toxicosis include:

• Depression

• Low body temperature

• Low blood pressure

• Decreased heart rate

• Sleepiness

• Unsteady movement

• Dribbling urine

• Vomiting

• Hypersalivation

• Dilated pupils

Treatment for cannabis toxicosis is usually focused on easing symptoms and making the animal comfortable until the effects have worn off. Vets may also administer activated charcoal to prevent further absorption of the toxins as they work their way through the digestive system.

The most effective treatment? Prevention. Keep pets safe by making sure all cannabis product, be it in plant or processed form, is well-secured and out of reach of curious paws.