Table 4.

Summary of studies on the efficacy of Cannabis derivatives in horses

Study design, formulation, dose, treatment duration and n. of recruited horses	Efficacy	Tolerability	Reference
Cannabis derivatives in sensitivity to touch
Case study on a 4-year-old Quarter Horse mare with a 5-week history of strong sensitivity to touch near the withers/shoulder region not responding to conventional therapeutic approaches (dexamethasone, gabapentin, magnesium/vitamin E, prednisolone and aquapuncture with vitamin B12), to evaluate the efficacy of a pure crystalline CBD formulation on allodynia. Initial CBD dose was 250 mg orally twice daily for 60 days. The dose was then decreased by one-half, then again adjusted to the initial level, and gradually decreased during two following months, reaching a maintenance dose of 150 mg once a day.	After the 250 mg dose the condition significantly improved 36 h after treatment beginning.	N.R.	Ellis and Contino 2021
	The reduction of the CBD dose resulted in a recurrence of the clinical signs after one day. With the reinstatement of the initial dose and its following gradual reduction, no repeated presence of increased sensitivity was evidenced.
	The owner described a 90% improvement.
Cannabis derivatives in crib-biting and wind-sucking
Case report on a 22-year-old mare suffering from chronic crib-biting and wind-sucking started at the age of 7 years old and progressively worsened over the years to evaluate the efficacy of isolated CBD (0.5 mg/kg orally twice a day for four weeks).	Between the first and second weeks of treatment a significant decrease in the hours spent crib-biting and wind-sucking was observed, with a gradual and constant enhancement of appetite.	No adverse events were reported among those carefully monitored (colic, lethargy, inappetence, hyperthermia, diarrhea, sialorrhea, cardiorespiratory disturbances, and ataxia).	Cunha et al. 2023
Cannabis derivatives in chronic pain from osteoarthritis (OA)
Randomized, placebo-controlled study to evaluate the efficacy of a commercial hemp oil containing 15% CBD, administered OTM at a dose of 0.03mg/kg every 24 h for 2 weeks, in relieving pain in 12 horses with osteoarthritis The CBD treatment was included in a classical pharmacological regimen, witha control group treated with the traditional analgesic (phenylbutazone) only.	A significant reduction in the Horse Chronic Pain Scale (HCPS) scores was seen in both groups. However, lower HCPS scores were recorded in the CBD group. A significant reduction in heart rate, respiratory rate, white blood cell counts and oxidative stress was also recorded.	The addition of a CBD-based product to the analgesic protocol was well tolerated, as no adverse effects were observed.	Interlandi et al. 2024

N.R.: Not reported