Furthermore, Form 1 showed less THCA retention than either the soft chew Form 3 or Form 2 at weeks 1 and 2. CBDA concentrations were statistically higher with Form 2 than the other forms, showing superior absorption/retention of CBDA. The 1- and 2-week steady-state concentrations were not significantly different between the two oils or the soft chew forms. CBDA and THCA concentrations were 2- to 3-fold higher than CBD and THC concentrations, respectively. Regardless of the form provided (1, 2, or 3) the 24-h pharmacokinetics for CBD, CBDA, and THCA were similar, with only Form 2 generating enough data above the lower limit of quantitation to assess pharmacokinetics of THC. Serum was analyzed for each cannabinoid or cannabinoid metabolite using liquid chromatography and tandem mass spectroscopy (LC-MS/MS). Dogs were then dosed every 12 h for 2 weeks and had further serum analyses at weeks 1 and 2, 6 h after the morning dose to assess serum cannabinoids. Six purpose-bred female beagles were utilized for study purposes, each having an initial 7-point, 24-h pharmacokinetic study performed using a dose of 2 mg/kg body weight of CBD/CBDA (~1 mg/kg CBD and ~1 mg/kg CBDA). In addition, we assess the metabolized psychoactive component of THC, 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC) and CBD metabolites 7-hydroxycannabidiol (7-OH-CBD) and 7-nor-7-carboxycannabidiol (7-COOH-CBD) to better understand the pharmacokinetic differences between three formulations regarding THC and CBD, and their metabolism. Examination of the pharmacokinetics of CBD, CBDA, THC, and THCA on three oral forms of CBD-rich hemp extract that contained near equal amounts of CBD and CBDA, and minor amounts (<0.3% by weight) of THC and THCA in dogs was performed. Many products contain small amounts of Δ9-tetrahydrocannabinol (THC), and precursor carboxylic acid forms of CBD and THC known as cannabidiolic acid (CBDA) and tetrahydrocannabinolic acid (THCA). 5Toxicology Research Laboratory, Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, IL, United StatesĬannabidiol (CBD)-rich hemp extract use is increasing in veterinary medicine with little examination of serum cannabinoids.4Ellevet Sciences, Product Development and Scientific Communications, Portland, ME, United States.3University of Florida Comparative Diagnostic and Population Medicine, Gainesville, FL, United States.2Department of Molecular Medicine, Cornell University College of Veterinary Medicine, Ithaca, NY, United States.1Department of Clinical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY, United States.Talsma 3, Stephen Cital 4, Alex Lyubimov 5, Asif Iqbal 5 and Alexander Zakharov 5