cocker spaniel dog lying on the grass

Welfare and Behaviour

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

A new study, published in Frontiers in Veterinary Science, has produced evidence supporting the safety of cannabidiol (CBD) for longer-term use in healthy dogs. This project adds to a growing body of scientific research focused on investigating the safety and efficacy of CBD in companion animals.  

Why study cannabidiol use in pets?  

The cannabis plant comes in two varieties: hemp and marijuana, both of which contain CBDA, which is only converted to CBD when it is processed.  CBD products formulated for pets are derived from hemp, which has high levels of CBD, but contains trace amounts of THC, too little to cause psychoactive or toxicity issues. 

For those seeking CBD solutions for their pets’ health issues, like anxiety or pain relief, there is a lack of scientific evidence on how well these products work, what doses are effective and whether CBD is even safe to feed to pets over the long term.  

CBD is already legal in some countries, but not regulated.  CBD pet treat and supplement products are not approved for sale in all markets. At Mars, we do not currently manufacture any such products. We care deeply about furthering scientific knowledge in service of our Purpose: A BETTER WORLD FOR PETS. Currently, global regulatory bodies, such as the FDA and EFSA, don’t support the use of CBD-containing products in pets due to lack of robust safety and efficacy data. That’s why, through a series of rigorous, ethical and high-quality research with cats and dogs, we’re investigating the safety and efficacy of CBD. Our aim is to contribute to a growing body of scientific evidence, lay a foundation for customers to demand science-backed products, and arm our veterinarians with the science they need to help pet owners make the right choices for their pets.  


What did this safety study find? 

In 2020, our scientists at the Waltham Petcare Science Institute began a series of studies seeking to establish safe and efficacious levels of CBD for cats and dogs. 

The aim of this first, randomised, placebo-controlled, and blinded study was two-fold:  

  • To demonstrate tolerance of a once-daily oral dose (4 mg/kg of body weight) broad-spectrum THC-free CBD over a six-month period to healthy adult dogs. The team ensured the dose was THC-free prior to administration. 
  • To quantify the level of CBD in the dogs’ fasted plasma, urine, and faeces over the same period.  

Researchers assessed a broad range of health measures, including biochemistry, haematology and urinalysis, in addition to fortnightly veterinary examinations, twice daily wellbeing observations, and a daily quality-of-life survey. These measures were taken before, then after two, four, 10, 18, 26 weeks of exposure, followed by four weeks of washout. CBD concentrations were measured at the same intervals in plasma, faeces and urine. 

The study demonstrated that a daily oral dose of CBD at this concentration and duration was well-tolerated by a cohort of clinically healthy adult dogs. The study authors warned against a possible over interpretation of the results, stressing that any interactions between CBD, disease and drugs still need to be understood.  

We know pet owners and veterinarians alike want to provide pets with health care and diets that match their own values and experiences. Establishing the safety of CBD in healthy dogs is a significant milestone as we advance our understanding of the compound’s effectiveness as an intervention to treat anxiety and pain.