Starting in October of this year, veterinarians licensed in Nevada will be able to recommend and administer hemp and cannabidiol products with a tetrahydrocannabinol content of no more than 0.3% without fear of sanctions from the state licensing authority.
Earlier this year, Governor Steve Sisolak signed Assembly Bill 101, which will make Nevada the first state to legalize the use of cannabinoids as veterinary treatment. The Nevada Board of Veterinary Medical Examiners helped write AB 101, which supported the Nevada VMA, according to NVMA executive director Michelle Wagner.
Bill sponsor Steve Yeager introduced the measure in February because Nevada law was unclear whether veterinarians were allowed to administer CBD products or to discuss with pet owners.
“Because of the ambiguity in our law, I have learned that many vets have chosen not to speak to pet owners about CBD for fear of being disciplined,” said Yeager. “This put pet owners in a difficult position as CBD products are generally unregulated and it would be difficult for a pet owner to know exactly what to buy or give without the professional advice of a veterinarian.”
Nevada voters approved medical marijuana for people through a ballot initiative in 2000. Cannabis became legal for recreational use in the state on January 1, 2017, following a 2016 election.
AB 101 met no resistance and passed the State Assembly and Senate without a single no, Yeager explained.
“I hope, of course, that other states will follow Nevada’s lead and give licensed vets confidence that they can administer CBD or talk to patients about it without fear of disciplinary action,” he said. “The bill itself is pretty simple and therefore a good model for other states.”
Although products containing 0.3% or less THC are exempt from the Federal Controlled Substances Act, the products are covered by the Federal Food, Drugs, and Cosmetics Act if used therapeutically or in animal feed. The Food and Drug Administration considers the therapeutic use of these products to be the use of unapproved drugs.
A simple question
But do medical cannabinoids actually help animal patients?
It’s a deceptively simple question at the heart of an animal health problem complicated by a jumble of federal and state regulations, research challenges, and species-specific pharmacokinetics.
Dr. Dawn Boothe is Professor of Veterinary Physiology and Pharmacology at Auburn University, studying the potential of cannabis as a veterinary treatment. She tried to understand the issues during her Medical Cannabinoids Revisited presentation at the AVMA Virtual Convention 2021 on August 1st.
The cannabis sativa plant contains more than 90 unique compounds or cannabinoids, including CBD and THC, as well as nearly 500 other terpenoids and phenylpropanoids. For several millennia, humans have used cannabinoids for pain, epilepsy, gastrointestinal disorders, and even infections.
Dr. Boothe said research interest in the therapeutic uses of cannabis in the United States essentially stalled in 1971 with the federal controlled substances act that listed cannabis as a List 1 drug, meaning the federal government did not consider cannabis to be therapeutic properties and a high potential for abuse.
“That has changed in the last few decades as states become increasingly aware of medicinal cannabinoids,” said Dr. Boothe. “But I shudder sometimes at how much we would have learned if we had taken a different path in our response to cannabis.”
The federal government’s position on cannabis has weakened somewhat in recent years, particularly with the 2018 Farm Bill 2018 deleting industrial hemp with a THC content of 0.3% or less from the Controlled Substances Act. That is, the use, sale, and possession of cannabis with THC levels greater than 0.3% is federally illegal, despite laws in many states that allow it in various circumstances.
Make everything clear
The restrictions on veterinarians have not diminished the interest of pet owners, who have at their disposal a veritable pharmacopoeia of CBD products that claim to treat a wide variety of animal diseases and behavioral problems.
None of the products are FDA approved, which, as Dr. Boothe stated that it raises concerns about variability in cannabinoid concentrations, mislabeling, and contamination with harmful additives such as fentanyl or synthetic cannabinoids.
“If you are looking for a product with a Certificate of Analysis that you can trust – like I would – visit the USDA (US Department of Agriculture) website and see the laboratories that the DEA (Drug Enforcement Administration) approved as suitable for the analysis of hemp plants, ”said Dr. Boothe. “That can at least increase the validity for this product.”
The question then arises as to what constitutes a therapeutic dose of cannabinoid in a particular species and which formulations actually deliver this dose to the animal patient. There is evidence that the type of CBD administered in dogs, such as in an oily soft capsule, may increase oral bioavailability, according to Dr. Boothe.
“Hemp seed oil, sesame seed oil, and medium chain triglycerides are the most common oils,” she said. “We need to see data to show the differences in oral bioavailability between these different compounds.”
Cats are more demanding. “We are going to need some good pharmacokinetic studies to give us information about dosage and cats,” said Dr. Boothe. “We have shown that intake varies in cats, but like dogs, feeding increases the intake.”
Dogs appear to be far more tolerant of CBD than THC, which when given intravenously in smaller, less concentrated doses than CBD, causes ataxia. Dogs have also been found to develop a tolerance to cannabinoids over time.
“My comfort zone with CBD is much larger than with THC,” said Dr. Boothe. She highlighted a report from the Veterinary Clinics of North America on marijuana toxicology, which showed that patients who received CBD were much more likely to be asymptomatic than those who received a synthetic cannabinoid, or THC.
“In fact, pet deaths from marijuana are more likely due to their being given a medicinal chocolate, or likely a synthetic cannabinoid, not a phytocannabinoid,” or a cannabinoid found naturally in the cannabis plant, she explained.
A small but growing body of research shows that CBD is a safe and effective treatment for lameness and epilepsy in dogs, said Dr. Boothe, but more study is needed to prove this.
“I’m excited about CBD,” she said. “I think it’s a very secure connection. I think it is mostly claimed in combination with our traditional therapies – if the indication or disease is very mild, perhaps therapy on its own, but as the disease progresses, adjuvant therapy becomes important.
“And I think therapeutic drug monitoring should be an important tool to ensure that therapeutic levels have been achieved.”
