DogsNet was contacted today by an organisation asking for support in promoting owner-administered cannabinoids for dogs. Promotors claim that cannabinoids can “serve as an alternative medication to help treat symptoms in dogs with cancer, seizures or anxiety”.
This is an extremely worrying trend that goes hand in hand with the provision of online veterinary “consultations” and which encourages owners to take matters into their own hands. Owners who do so in the UK may run the risk of being prosecuted under the Veterinary Surgeons Act 1966 which makes it illegal for anyone other than a registered veterinary surgeon to diagnose illness and to prescribe or administer treatment to an animal. Additionally, veterinary surgeons in the UK must abide by the European Union Veterinary Medicines Directive (2001/82) which mandates them to prescribe as a first line treatment, preparations that are licensed for animal use where they exist and thereafter:
a. A veterinary medicine product authorised in the UK for use with another animal species for that condition, or another condition for that animal species.
b. If there is no such medicine:
i. An authorised human medicine or
ii. A veterinary medicine product not authorised in the UK, but authorised in another EU member state for use with any animal species
c. If there is no such medicine, a veterinary medicine product prepared extemporaneously by a pharmacist, veterinary surgeon or person holding a manufacturing authorisation for that type of product.
Anxiety, pain, cancers and seizures are all treated, often extremely efficaciously, by existing supplements and drugs, some of which come under the veterinary cascade.
In the case of anxiety, it is essential to determine the root cause before considering relief. Over the counter preparations for anxiety can be used effectively in conjunction with a professionally provided behavioural plan and should always be used with the knowledge of the animal’s veterinary surgeon.
It is also worth pointing out that animals cannot exhibit symptoms, which are subjective, but do exhibit signs, which are objective, and frequently missed by owners (and sometimes vets). Recognition of pain in particular can be problematic with even vets being reported as referring animals for behavioural problems when in fact the cause of the aberrant behaviour has been pain. The thought that owners would be dosing their animals with quack preparations whilst their underlying condition remains undiagnosed or untreated is horrifying.
A recent review of scientific literature regarding the use of cannabinoids in veterinary medicine noted that attempts to provide medical uses of cannabinoids in the 1960s ended in failure because the therapeutic effects could not be isolated from the psychotropic effects”. The Veterinary Poisons Information Service states that “Clinical effects of cannabis toxicity in dogs are similar to those reported in humans, and usually appear after 30-90 minutes if ingested, and 6-12 minutes if inhaled. Out of the 286 cases with follow up presented to VPIS [this was within a twelvemonth period], the most common clinical effects reported were ataxia, dilated pupils, vomiting, drowsiness and hyperaesthesia. Both bradycardia and tachycardia were documented as well as hyperthermia and hypothermia; only 18 dogs remained asymptomatic…While dogs typically recover from cannabis intoxication with no long-term effects, complications, the exposure to a potent strain or the ingestion of a large amount of the drug can be fatal.”
The way that cannabinoids affect the human and canine body is extremely complex. Cannabinoids do not only affect the body’s cannabinoid receptors but those that affect mood-altering hormones as well as those that affect inflammatory processes. Thus far, evidence concerning the effects of cannabinoids in animals has only been found at an experimental level during the pre-clinical testing of specific substances in laboratory rodents (mice, rats and guinea pigs). A much smaller number of published papers concern pre-clinical testing of cannabinoids in rabbits, ferrets, cats and dogs and very few of those provide reliable sources concerning the clinical use of cannabinoids in veterinary medicine for companion animals. The majority of articles published about companion animals concern marijuana poisoning and its treatment. One study tested the effects of an ophthalmic solution containing 2% THC on aqueous humour flow rate and intraocular pressure in 21 clinically normal dogs. Aquaeous humour is a fluid that helps to regulate the shape of the eye and pressure is measured as an indication of, amongst other things, glaucoma. The study found a moderate reduction in mean intraocular pressure in the dogs. Another study found a reduction in skin inflammation produced by hypersensitivity to the Ascaris antigen in six beagles that were injected with Palmitoylethanolamide (PEA).
Not something that an owner would be fiddling round with and hardly a body of evidence in support of clinical use.
The literature review concluded “It should also be taken into account that the majority of cannabinoids possess psychotropic properties which may change the behaviour of animals (eg locomotion) and that these substances have addictive potential”.
Furthermore, the authors state: “The reluctant attitude of veterinarians towards the use of cannabinoids/medical marijuana in animals could be associated with the risk that owners will make attempts to treat their animals using cannabis-based products, which can lead to intoxication”.
They are not kidding. The VPIS raised similar concerns in 2016 when they noted “With recent votes legalising the use of both recreational and medicinal cannabis in some US states (Colorado, Washington, Alaska and Oregon) and the growing popularity of cannabis-infused pet products, there has been a lot of discussion around its effect in animals. The US’ Pet Poison Helpline have reported a 200% increase in the number of enquiries they have received on this agent…Trupanion, an American pet insurance company, reported receiving a claim of over $6,000 for a Shetland Sheepdog who ate a tray of “weed brownies” and needed to be hospitalised for seven days.”
The fact that various over the counter preparations are openly on sale in the UK would suggest that they are so lacking in potency as to be virtually ineffective. They will probably prove to be profitable because, let’s face it, some people still believe in homeopathy and some vets still peddle it.
There is certainly scope for investigating the potential for clinical use of cannabinoids but, there are already plenty of products available that have been proven to be effective and, more to the point, are dispensed by qualified professionals.
At best, dosing your dog with cannabis (aka snake) oil will probably not do much harm in and of itself (other than to your pocket), but not getting professional veterinary advice almost certainly will if your dog is suffering from any of the things that the purveyors of these products claim to be able to alleviate.
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