Long-term daily feeding of cannabidiol is well-tolerated by healthy dogs

Abstract

Cannabidiol (CBD) containing dog food and treats are widely commercially available, mirroring the growing popularity of CBD as a supplement for humans. Despite this, experimental evidence of the safety and efficacy of long-term oral exposure in dogs is lacking. The purpose of this study was to address the gap in knowledge around the longer-term suitability and tolerance of a broad-spectrum CBD (THC-free) distillate in clinically healthy dogs. The study was a randomized, placebo-controlled, and blinded study where one group of twenty dogs received daily CBD capsules at a dose of 4 mg/kg of body weight (BW) for a period of 6 months. The control group of twenty dogs received placebo capsules. A comprehensive suite of physiological health measures was performed throughout the study at baseline, and after 2, 4, 10, 18, and 26 weeks of exposure, followed by 4 weeks of washout. CBD concentrations were measured at the same cadence in plasma, feces and urine. Health measures included biochemistry, hematology, urinalysis, in addition to fortnightly veterinary examinations, twice daily well-being observations, and a daily quality-of-life survey. Biochemistry and hematology showed no clinically significant alterations apart from a transient elevation in alkaline phosphatase (ALP) in just over half of the dogs receiving CBD. This elevation was observed in the absence of concurrent elevations of other liver parameters, and without any adverse effects on health and wellbeing. Furthermore, bone alkaline phosphatase (BALP) was simultaneously elevated with a significant, strong (r > 0.9) positive correlation between the two measures, suggesting that the elevation of total ALP was at least partly due to the bone-derived isoform. This study provides evidence that a once-daily oral dose of 4 mg CBD/kg BW is well tolerated in clinically healthy dogs for a duration of 6-months.

A single dose of cannabidiol (CBD) positively influences measures of stress in dogs during separation and car travel

“…A blinded, parallel design study was conducted at the Waltham Petcare Science Institute to determine the anxiolytic effects of CBD in parallel with a long-term safety study (40). Over this 6 month study dogs were given daily administration of CBD and indicators of stress were measured following exposure to acute and chronic stress-inducing events.…”

“…Dogs were weighed to establish an accurate dose of CBD relative to individual bodyweight. The targeted oral dose for each dog was 4 mg/kg bodyweight with an acceptable range of 3.38-4.44 mg/kg bodyweight (40). This study was approved by the Waltham Animal Welfare and Ethical Review Body (80265) and conducted under the authority of the Animals (Scientific Procedures) Act 1986.…”

“…CBD is also increasingly used within the veterinary industry (37) and it is reported that short term oral dosing of CBD up to 20 mg/kg daily (38) and single oral gavage dosing of 62 mg/kg does not cause any significant adverse effects in healthy dogs (39). Additionally, a recent 6-month safety study found 4 mg/kg oral daily dosing (40) was well-tolerated suggesting CBD is safe for healthy dogs when fed appropriately. However, less is empirically known regarding the efficacy of this compound in dogs, with the majority of clinical studies examining the efficacy of CBD in alleviating the symptoms of pain resulting from osteoarthritis (37,41,42).…”

Evaluation of the efficacy of a cannabidiol and cannabidiolic acid rich hemp extract for pain in dogs following a tibial plateau leveling osteotomy

“…The elevation of liver values in this cohort, particularly ALP, is consistent with previous reports in human, murine, and canine literature, and thought to be due to induction of cytochrome p450 mediated oxidative metabolism ( 9 , 14 , 15 , 19 , 24 – 26 ). In a recent trial in dogs receiving 4 mg/kg daily of CBD for 6 months, similar rises in ALP were identified which returned to baseline within 4 weeks of cessation of CBD ( 31 ). However, elevation of liver enzymes is inconsistent in the literature, with multiple reports in canine patients having no identified changes, particularly in young healthy cohorts ( 6 , 8 , 15 ).…”

“…While no benefit was identified in this present study, interestingly a recent abstract using the same product used in this study at a 5 mg/kg dose every 8 h may decrease pain scores in patients undergoing intervertebral disk disease surgery ( 30 ). Currently, no toxic dose has been established with reports of 20 mg/kg orally every 12 h for 6 weeks, 4 mg/kg once daily for 6 months, and lower doses of 2 mg/kg every 12 h for 12 weeks being tolerated in dogs ( 19 , 28 , 31 ).…”