Page 86 - August 2019

CANNABIS USE IN HORSES
“Don’t assume that just because it’s from a plant that it’s safe. Anything that has a pharmacologic action, has the possibility of negative effects.”
A Controversial Topic
by Heather Smith Thomas
There are multiple species of Cannabis plants and several different “strains” within those species. Hemp includes varieties of Cannabis cultivated for production of fiber, seeds and their oils. Other varieties, often called marijuana, are used for medici- nal purposes in humans and as a recreational drug.
Cannabis plants have more than 100 chemi- cals called phytocannabinoids (the prefix “phyto” means plant). The two main ones of interest today are cannabidiol (CBD) and tetrahydrocannabinol (THC). Industrial hemp products are made from plants selected to produce abundant fiber. Some strains are bred to produce minimal levels of tet- rahydrocannabinol (THC), the main psychotropic constituent of cannabis. Marijuana’s THC content is usually 10% or more, and some marijuana plants today contain much more THC than they did several decades ago—sometimes as much as 25%, but hemp must have a THC content of 0.3% or less, according to federal and state laws. At this low level, cannabis products have no intoxicating effect, for people or animals.
Humans have been using cannabis for various purposes for many years, but because of the mind- altering effects of THC all forms of cannabis have been illegal in the U.S. until recently. With the Farm Act of 2018, industrial hemp (classified as having THC content of 0.3% or less) is no longer considered a controlled substance and is now a farm commodity, although THC remains a Schedule 1 drug with the Drug Enforcement Agency (DEA).
With this change in status, hemp is now utilized for many purposes including extraction of CBD for humans and animals. Pet owners and horsemen are using multiple products in a fast-growing market— for pain relief, calming and various medical condi- tions. Efficacy and safety of some of these products is questionable, however, because there has been very little research. Until passage of the 2018 Farm Act, it was illegal to possess or conduct research on hemp as well as marijuana.
CBD PRODUCTS FOR HORSES
Today, research is trying to catch up and fill
gaps in knowledge about potential uses for can-
nabis products in animals, efficacy, safety, dosage, etc. Several companies now sell CBD products for horses. For instance, Trish Wilhelm CVT, VCC, and Chelsea Luedke, DVM, MS, Co-Founder and Chief Veterinary Advisor of VetCS in Centennial Colorado, started their company two years ago. As an equine veterinarian, Luedke applies clinical experience to product development, manufacturing high-quality CBD hemp extracts for horses.
“We came to market with some products in 2018, with the purpose of creating a reliable solu- tion for pet and horse owners,” says Luedke. “We’d seen a lack of scientific evidence in many prod- ucts offered, and health benefit claims obviously overreaching any FDA standards. We wanted to address some of those problems, clarify informa- tion on dosing, and provide transparency regard- ing where ingredients come from.
“Many horse and pet owners were trying to adapt human products (either medical marijuana, or hemp they’d grown themselves to make homemade batches) for their animals,” she continued. “In dogs, for instance, they were using human CBD oils that contain xylitol (a sweetener), which is toxic for dogs. When horse owners started using hemp, many were under-dosing their horses with CBD.
“Often people tried putting a few drops in the horse’s mouth and didn’t see any difference in what- ever condition they were trying to treat. Also, when we were doing our initial studies, we were using CBD isolate in oil, but these products need to be absorbed through the mucosa of the oral cavity. The horse’s gastric pH is low, which affects the bioavailability of many drugs. Formulations like gel caps and oils may absorb quite well in humans via the gut, but not as well in horses.
“Oil is great, except it is so thin you can’t get it to stay in the horse’s mouth very well and it’s difficult to
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SPEEDHORSE, August 2019
EQUINE HEALTH