There have been numerous reports of cannabis poisoning in dogs and cats, primarily due to the consumption of marijuana products intended for humans. The symptoms of marijuana intoxication in pets include loss of coordination, confusion, dilated pupils, urinary incontinence, heightened sensitivity, tremors, and vomiting. These side effects are believed to be caused by the ingestion of THC, a lipid-soluble compound that activates psychotropic CB1 receptors.
While Δ-9-THC has a high safety margin, with a lethal dose (LD50) estimated to be over 3,000 mg/kg in dogs, there have been cases of death after the ingestion of food products containing highly concentrated THC butter. It is important to note that pet cannabis products differ significantly from those intended for human use. These products are made from hemp (C. sativa) and contain very low to undetectable levels of THC.
Most studies on safety and pharmacokinetics have utilized hemp extracts, oils, or chewables containing CBD, with minimal levels of other cannabinoids and THC levels below 0.3%. In these studies, CBD doses administered to dogs ranged from 1 to 20 mg/kg of body weight per day. Although CBD and THC are different cannabinoids, the tested CBD doses are typically 500 to 3,000 times lower than the estimated lethal dose of THC.
Most veterinary studies on cannabinoid safety and tolerability are relatively recent. The sales of CBD products increased after hemp was descheduled from the Farm Bill in 2018, leading to a growing interest among companies and researchers in determining safe and effective doses for dogs and cats with specific conditions. However, caution must be exercised when extrapolating CBD safety and pharmacokinetic information across different species, as there may be significant differences in cannabinoid receptors.
For instance, a study by Ndong et al. found that while CBD exhibited similar affinity to canine CB2 receptors as it did to human and rodent CB2 receptors, its potency was approximately 30 times lower in dogs compared to the other species tested. Let’s always remember – CBD products for dogs should not be mistaken for human products and vice versa.