Aggressive dogs are becoming significantly less hostile after taking cannabis-derived supplements, according to the largest-ever study of CBD use in companion animals.
Researchers from Arizona State University and the University of Tennessee analysed data from 47,355 dogs and found that while animals prescribed these supplements often start as the most hostile, their temperament shifts distinctively after prolonged use.
The study, published in Frontiers in Veterinary Science, used data from the Dog Ageing Project to track pets between 2019 and 2023, revealing that 7.3 per cent of US companion dogs are now being given CBD or hemp products.
“Behaviorally, dogs given CBD products for multiple years are initially more aggressive compared to dogs not receiving those products, but their aggression becomes less intense over time,” said senior author Dr Maxwell Leung, director of the Cannabis Analytics, Safety and Health Initiative at Arizona State University.
The research identified clear demographic trends among the canine users. Dogs receiving CBD were on average three years older than non-users and were significantly more likely to suffer from serious health conditions.
Dogs with dementia
The highest prevalence of use was found among dogs with dementia (18.2 per cent), followed by those with osteoarthritis (12.5 per cent) and cancer (10 per cent).
Male dogs were nine per cent more likely to receive supplements than females, and usage was higher in US states where medical cannabis is legalised for humans.
“This long-term behavioural change highlights the potential of CBD as a therapy for canine behavioural issues,” said co-author Dr Julia Albright, an associate professor at the University of Tennessee College of Veterinary Medicine.
However, the calming effect appeared specific to aggression. The study found no similar improvement for other behaviours such as agitation or anxiety, creating a scientific puzzle given that anxiety is often a root cause of hostility.
“Most canine aggression is related to underlying stress or anxiety – a fight or flight response that kicks in,” said Albright. “It is unclear why only aggression but not other types of anxious or agitated behaviours seemed to be improved with CBD treatment.”
The team warned that owners should choose reputable brands and monitor dosage carefully, as CBD products can cause adverse effects, including gastrointestinal issues and diarrhoea.
