Behavior

Recent advances in cannabidiol (CBD) use in canines and felines for anxiety management, pain management, and anti-inflammatory effects were reviewed using a literature search conducted with the following keywords: CBD, anxiety, inflammation, pain, dogs, cats, and companion animals. For decades, research on CBD has been hindered due to the status of cannabis (C. sativa L.) as an illicit drug. Limited safety data show that CBD is well-tolerated in dogs, with insufficient information on the safety profile of CBD in cats. Upon oral supplementation of CBD, elevation in liver enzymes was observed for both dogs and cats, and pharmacokinetics of CBD are different in the two species. There is a significant gap in the literature on the therapeutic use of CBD in cats, with no feline data on anxiety, pain, and inflammation management. There is evidence that chronic osteoarthritic pain in dogs can be reduced by supplementation with CBD. Furthermore, experiments are required to better understand whether CBD has an influence on noise-induced fear and anxiolytic response. Preliminary evidence exists to support the analgesic properties of CBD in treating chronic canine osteoarthritis; however, there are inter- and intra-species differences in pharmacokinetics, tolerance, dosage, and safety of CBD. Therefore, to validate the anxiety management, pain management, and anti-inflammatory efficacy of CBD, it is essential to conduct systematic, randomized, and controlled trials. Further, the safety and efficacious dose of CBD in companion animals warrants investigation.

Posttraumatic stress disorder (PTSD) is an incapacitating syndrome that follows a traumatic experience. Predator exposure promotes long-lasting anxiogenic effect in rodents, an effect related to symptoms found in PTSD patients. Cannabidiol (CBD) is a non-psychotomimetic component of Cannabis sativa with anxiolytic effects. The present study investigated the anti-anxiety actions of CBD administration in a model of PTSD. Male Wistar rats exposed to a predator (cat) received, 1 h later, singled or repeated i.p. administration of vehicle or CBD. Seven days after the stress animals were submitted to the elevated plus maze. To investigate the involvement of 5HT1A receptors in CBD effects animals were pre-treated with WAY100635, a 5HT1A receptor antagonist. To explore possible neurobiological mechanisms involved in these effects, 5HT1A receptor mRNA and BDNF protein expression were measured in the hippocampus, frontal cortex, amygdaloid complex and dorsal periaqueductal gray. Repeated administration of CBD prevented long-lasting anxiogenic effects promoted by a single predator exposure. Pretreatment with WAY100635 attenuated CBD effects. Seven days after predator exposure 5HT1A mRNA expression was up regulated in the frontal cortex and hippocampus. CBD and paroxetine failed to prevent this effect. No change in BDNF expression was found. In conclusion, predator exposure promotes long-lasting up-regulation of 5HT1A receptor gene expression in the hippocampus and frontal cortex. Repeated CBD administration prevents the long-lasting anxiogenic effects observed after predator exposure probably by facilitating 5HT1A receptors neurotransmission. Our results suggest that CBD has beneficial potential for PTSD treatment and that 5HT1A receptors could be a therapeutic target in this disorder.

Selective stimulation of carotid chemoreceptors by intravenous infusion of low doses of potassium cyanide (KCN) produces short-lasting escape responses that have been proposed as a model of panic attack. In turn, preclinical studies suggest that facilitation of the endocannabinoid system attenuate panic-like responses. Here, we compared the effects of cannabinoid-related compounds to those of alprazolam, a clinically effective panicolytic, on the duration of the escape reaction induced by intravenous infusion of KCN (80 μg) in rats. Alprazolam (1, 2, 4 mg/kg) decreased escape duration at doses that did not alter basal locomotor activity. URB597 (0.1, 0.3, 1 mg/kg; inhibitor of anandamide hydrolysis), WIN55,212-2 (0.1, 0.3, 1 mg/kg; synthetic cannabinoid), arachidonoyl-serotonin (1, 2.5, 5 mg/kg; dual TRPV1 and anandamide hydrolysis inhibitor), and cannabidiol (5, 10, 20, 40 mg/kg; a phytocannabinoid) did not decrease escape duration. Alprazolam also prevented the increase in arterial pressure evoked by KCN, while bradycardia was unchanged. This study reinforces the validity of the KCN-evoked escape as a model of panic attack. However, it does not support a role for the endocannabinoid system in this behavioral response. These results might have implications for the screening of novel treatments for panic disorder.

Among the phytocomplex components of Cannabis sativa L., cannabidiol (CBD) has a recognised therapeutic effect on chronic pain. Little is known about the veterinary use of CBD in dogs. Even less is known on the effects of CBD on dog behaviour, especially in shelters. The purpose of this study was to determine if CBD affects stress related behaviour in shelter dogs. The sample consisted of 24 dogs divided into two groups that were created by assigning the dogs alternately: 12 dogs were assigned to the treatment group and 12 to the control group. Extra virgin olive oil, titrated to 5% in CBD was given to treated group; the placebo consisted of olive oil only, dispensed daily for 45 days. Behavioural data were collected using the ‘focal animal’ sampling method with ‘all occurrences’ and ‘1/0’ methods for 3 h: before (T0), after 15 days (T1), after 45 days of treatment (T2) and after 15 days from the end of the treatment (T3). Treated dogs showed reduced aggressive behaviour toward humans following the treatment (Friedman Test: χ2 = 13.300; df = 3; N = 12; p = .004; adj. sig. p = 0.027), but the difference in the decrease of aggressive behaviour between the two groups was not significant (Mann–Whitney U test, T2–T0: Z = − 1.81; N = 24; p = 0.078). Other behaviours indicative of stress, such as displacing activities and stereotypes, did not decrease. Despite some non-significant results, our findings suggest that it is worth doing more research to further investigate the effect of CBD on dog behaviour; this would be certainly valuable because the potential for improving the welfare of dogs in shelters is priceless.