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CBD & THC Use in Cats

Lisa Sams Ebner, DVM, MS, DACVAA, CVA, Lincoln Memorial University, Harrogate, Tennessee

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In the literature

Kulpa JE, Paulionis LJ, Eglit GMI, Vaughn DM. Safety and tolerability of escalating cannabinoid doses in healthy cats. J Feline Med Surg. 2021;23(12):1162-1175.


Efficacy studies of therapeutic cannabinoid use in dogs are available, but literature evaluating use in cats is lacking. 

This randomized, placebo-controlled, blinded study* aimed to determine the safety and tolerability of increasing doses of cannabidiol (CBD) and tetrahydrocannabinol (THC), alone and in combination, in healthy cats using a well-defined cannabis formulation. 

Twenty healthy adult cats were placed in 1 of 5 groups. Placebo groups received either sunflower (SF) or medium-chain triglyceride (MCT) oil. Cannabidiol groups received CBD in MCT oil, THC in MCT oil, or CBD/THC (1.5:1 ratio) in SF oil. Up to 11 escalating oral doses of each formulation were administered to fasted subjects with at least 3 days between doses. 

Cats were monitored for adverse effects, and vital signs were recorded at predetermined intervals. Blood samples for CBC and serum chemistry profile were collected at 24 hours and 7 days after the final dose was administered. Blood was also drawn for cannabinoid analysis immediately prior to and 1, 2, 3, 4, 6, and 24 hours (±15 minutes) following the ninth dose; 4 and 24 hours (±15 minutes) following the tenth and final (eleventh) doses; and 7 days following the final dose.

All adverse effects were mild and did not require intervention. Most common effects were GI (27.6%), respiratory (15.4%), neurologic (14.6%), and ocular (8.3%). Nonspecific signs affecting multiple body systems (29.9%) were also documented. 

In the placebo groups, most cases of vomiting and diarrhea occurred when MCT oil was given. 

Nonspecific signs (most commonly, lethargy and hypothermia) were more frequently noted in cats in the CBD/THC treatment group than in those receiving CBD or THC alone. On average, lethargy began more quickly (≈2.8 hours) and lasted for a shorter period (1.2 hours) in the CBD group than in the THC group (lethargy began after 4.2 hours and lasted 8 hours) or the CBD/THC group (lethargy began after 4.3 hours and lasted 5.7 hours). Ataxia was seen in all patients in the CBD/THC and THC groups. Cats in the CBD group did not demonstrate ataxia until the ninth and tenth doses. 

There were no clinically significant changes on CBC and serum chemistry profile in any treatment group. Levels of plasma cannabinoids and metabolites were higher after CBD/THC administration compared with CBD or THC alone, although the dose of each drug in the combination was less than the dose given alone. This suggests a pharmacokinetic interaction (eg, change in cannabinoid absorption, distribution, or elimination) between CBD and THC and warrants further investigation.


Key pearls to put into practice:


With the increased popularity of CBD and CBD/THC products for pets, it is important to be familiar with the adverse effects and potential benefits of these products, as well as variations in cannabis formulations and noncannabinoid components. The most common adverse effects include vomiting, lethargy, and ataxia. Other potential adverse effects that occur less frequently include hypersalivation, diarrhea, tachypnea, protrusion of the nictitating membrane, and vocalization.


According to the AVMA, state laws legalizing the use of cannabis in humans do not apply to animals.1,2 State practice laws should be consulted prior to making medical recommendations. Hemp-derived cannabis products (including CBD) cannot be recommended or prescribed with the intent to prevent or treat a medical condition.3


CBD (≤30.5 mg/kg), THC (≤41.5 mg/kg), and CBD/THC (≤13 mg/kg and ≤8.4 mg/kg, respectively) were well tolerated in young, healthy male and female cats. SF oil appeared to be tolerated better than MCT oil as a carrier. 

*This study was funded by Canopy Animal Health.


For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

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