The buzz surrounding medical marijuana legalization across the country has fueled pet owners’ interest in similar products to help manage their dogs’ health issues.
One of the big questions surrounding these products — at least until recently — has been “Is it safe to give cannabis- or hemp-based products to my pet?” Even more importantly, given the role of the kidneys in removing “drugs” from the body, should you give these products to a dog who has kidney disease?
We’ll answer those questions and review what you need to know if you’re thinking about giving a cannabis- or hemp-derived product to your dog.
CANNABIS CONFUSION: WHAT’S IN A NAME?
From a legal and regulatory perspective, there’s a lot riding on the words used to describe products made from cannabis plants, their parts or the chemicals extracted from them (aka cannabinoids).
“Cannabis” refers to the flowering plants belonging to the genus Cannabis, which includes both hemp (aka industrial hemp) and marijuana, as well as those products designed for therapeutic use. Cannabis sativa L. is the most common species of cannabis. It has been cultivated for millennia for use as food, fiber for clothes and rope, medicine and recreation. (As a side note, the L. stands for Linnaeus, the person who first named the plant species.)
Through genetic selection and human cultivation, different varieties of cannabis plants with different chemical profiles now exist within Cannabis sativa L. Industrial hemp varieties have been bred to grow tall with sturdy, high-fiber stalks and low levels (less than 0.3 percent) of THC (tetrahydrocannabinol), the ingredient in marijuana that that causes an altered state. Hemp varieties have naturally occurring high levels of CBD (cannabidiol), which doesn’t cause an altered state in either people or pets and is of interest to human and veterinary medicine. In contrast, marijuana varieties of Cannabis sativa L. have been specifically bred for THC amounts ranging from 5 to 30 percent on a dry-weight basis.
The Cannabis sativa L. plant contains more than 400 chemical compounds, including more than 100 cannabinoids such as THC and CBD. The first cannabinoid, cannabinol, was isolated in pure form from cannabis plants during the 1890s. Then, during the mid-1960s, CBD and THC were isolated. These findings led to the discovery of the endocannabinoid system (ECS), a network of receptors located in the brain, spinal cord and numerous other tissues to which THC — and other naturally occurring chemicals in the body — bind.
SUPPLY AND DEMAND LEADS TO MANY CBD- AND HEMP-BASED PRODUCTS
Do a Google search using the terms “CBD” and “pets,” and the results will number in the hundred millions. Obviously, many companies have jumped on the cannabis bandwagon to offer some type of CBD-containing pet product. Formulas range from oils that can be added to food to capsules to topical creams to CBD-infused treats. And sales of pet-specific cannabis and hemp products are booming.
While some products contain only CBD, other products include additional cannabinoids (but not THC) and terpenes, a class of naturally occurring compounds produced by a variety of plants including Cannabis sativa L. At least one company markets its products — which contain a proprietary whole-plant hemp extract — as hemp nutritional products.
A growing number of pet owners, especially those who have tried CBD and/or hemp products themselves, are looking for, buying and giving CBD and other hemp-based products to their dogs (and cats) for illnesses or conditions diagnosed by their veterinarians. Most of these products are used as part of a general health plan, to care for aging pets or for a specific behavioral condition. They’re also being used to treat pain, inflammation, arthritis, anxiety and seizures — despite a lack of either scientific evidence for their effectiveness or approval by the U.S. Food and Drug Administration (FDA). More on that later.
How can products from one plant species be used for so many medical conditions?
Similar to people, dogs (and cats) have an endocannabinoid system (ECS) that plays an important role in keeping several body systems in balance. Actually, all mammals have an ECS that’s involved in many physiological processes, including pain, mood, inflammation, stress and more.
Although the cannabinoid (CB) receptors CB1 and CB2 have been the focus of marijuana- and THC-related research, how CBD works is still being figured out. According to the CBD Project, more than 65 “targets,” such as other receptor types, have been identified in the scientific literature. Regardless of how it works, dog owners who have been giving CBD to their pets believe the products help.
BUT IS CBD SAFE? AND WILL IT WORK?
Since 2016, veterinary researchers at two universities — Colorado State University (CSU) and Cornell University — have been studying the short-term safety and effectiveness of CBD in dogs.
In the CSU safety and dosing study, dogs appeared to tolerate CBD whether it was applied as a topical cream or given as an oral capsule or oil. All dogs in the study experienced diarrhea, no matter which form or dose of CBD they received. In addition, bloodwork revealed some dogs had an increase in one liver enzyme (alkaline phosphatase), prompting the researchers to recommend a more extensive safety study.
Once the safety study was done, Colorado researchers began two clinical trials with client-owned dogs. One study set out to determine if CBD reduces seizure activity in epileptic dogs with poorly controlled seizures. The other study evaluated if CBD reduces pain associated with arthritis. Both studies are blinded and placebo controlled, meaning that veterinarians and dog owners don’t know if a dog is receiving CBD or not.
In the pilot clinical trial that studied CBD use in dogs with epilepsy, 89 percent of the dogs receiving CBD experienced a reduction in seizure frequency. As a result of these findings, a larger clinical study with CBD for dogs was started in January 2018. Those findings have yet to be published, although preliminary findings have been presented at some veterinary conferences.
No results have been published from the CSU pilot study looking at the effects of CBD on arthritis in dogs. However, veterinary researchers at Cornell have shared the findings from their pilot clinical trial.
The Cornell studies found that CBD was absorbed after dogs were given a single oral dose of an industrial hemp extract combined with olive oil. Additionally, no psychoactive effects were observed.
From there, researchers studied the ability of CBD oil to affect the pain scores and activity levels of arthritic dogs. Like the CSU studies, veterinarians and dog owners did not know which dogs were getting the CBD oil or the placebo oil. Dogs treated with CBD oil had a significant decrease in pain scores and a significant increase in their activity scores. In addition, veterinarians’ assessments found decreased pain during CBD treatment. While no side effects were reported by dog owners, bloodwork showed an increase in one liver enzyme during CBD treatment. No statistically significant differences in blood urea nitrogen, creatinine or phosphorus — blood values of concern in dogs with kidney disease — were found between dogs treated with CBD oil and those given placebo oil.
So far, the findings of pilot clinical trials are showing that CBD can help dogs with seizures and arthritis. However, more research is needed to understand the significance of the changes seen in bloodwork.
WHAT ABOUT CBD- OR HEMP-BASED PRODUCTS FOR DOGS WITH KIDNEY DISEASE?
Veterinary researchers know very little about the effects of CBD- or hemp-based products on canine kidneys, although they realize that the kidneys have a role in eliminating CBD-related compounds from the body. Drug metabolism studies conducted during the late 1980s and early 1990s found over 40 products of CBD breakdown in the urine of dogs given CBD.
Although CBD appears to help manage pain in dogs, not all dogs experience pain during the course of kidney disease. It really depends on the underlying cause of the disease. Dogs with kidney disease do experience appetite loss and, at least anecdotally, CBD might help stimulate appetite. But until more is known about what, if any, effects CBD may have on the kidneys themselves, and the appropriate dose for improving a dog’s appetite, it may be better to use proven approaches to appetite stimulation.
ARE CBD- AND HEMP-BASED PRODUCTS FOR DOGS LEGAL?
To say the laws and regulations regarding the marketing and sale of hemp-based CBD products for pets are convoluted and confusing is an understatement.
Many companies that make and sell hemp-derived CBD products for pets generally say their products are “legal in all 50 states.” That’s not exactly true, according to the Brookings Institution.
The Agricultural Act of 2014 (aka “the Farm Bill”) allowed cultivation of industrial hemp, provided it did not contain more than 0.3 percent THC on a dry-weight basis. In addition, the hemp could only be grown “for purposes of research conducted under an agricultural pilot program or other agricultural or academic research” in states that have laws allowing its production.
The Agriculture Improvement Act of 2018 (aka “the 2018 Farm Bill”) legalized industrial hemp with extremely low (less than 0.3 percent) THC content by removing hemp from the Controlled Substances Act. While legal CBD products will be more broadly available, not all CBD products are legal moving forward. Any cannabinoid — including CBD — that is derived from hemp will be legal, if and only if that hemp is produced by licensed growers and in a manner consistent with the Farm Bill, associated federal regulations and associated state regulations.
In addition to these laws, the Food, Drug and Cosmetic Act gives the FDA the authority to regulate products containing cannabis or cannabis-derived compounds. That includes products containing CBD made from hemp. In June 2018, the FDA approved a human drug that contains CBD for the treatment of seizures associated with two rare forms of epilepsy. As a result, CBD is effectively considered a drug, and any CBD-containing product for pets that hasn’t gone through FDA review and approval will likely be considered an unapproved new animal drug. The FDA has previously sent warning letters to companies making claims that their CBD products can treat medical issues in pets, and the FDA will continue their market surveillance.
THE BOTTOM LINE?
The scientific, legal and regulatory landscape for hemp- and cannabis-related products is evolving, with more changes to come. If you are interested in giving a CBD- or cannabinoid-containing product to your dog with kidney disease, please discuss it first with your veterinarian. You will also want to do your homework regarding your state’s laws and whether they permit use of these products.
