Estimated reading time: 5 minutes
More veterinarians are turning to medicinal cannabis as an alternative to conventional therapies. But as an emerging clinical field with limited scientific investigation, its legitimacy as a bone fide treatment is still being questioned. By Tracey Porter
On 29 February 2016, the Australian Government legalised access to medicinal cannabis. After many anecdotal reports of the potential health benefits of cannabidiol (CBD)—a non-psychoactive component in cannabis derived from the hemp plant—many vets began taking a closer look at how CBD might be used to treat pets including those with osteoarthritis and chronic pain, anxiety, atopic dermatitis and other skin ailments, cognitive dysfunction, poor appetite and many inflammatory conditions, as well as its effectiveness in palliative care and cancer support.
Those championing the use of medicinal cannabis for domestic pets argue for its inclusion as a treatment when conventional therapies don’t work and as an adjunct to traditional medications in the treatment of, for example, idiopathic epilepsy to further reduce seizure duration, severity, and frequency.
Those against its use claim inconsistent product labelling, complex regulations, and its online availability can mean many of these formulations are not assessed for the purity or consistency of their cannabinoid content. Moreover, non-prescription CBD products may contain higher levels of the active psychoactive ingredient tetrahydrocannabinol (THC) leading to an increase in the number of pets requiring treatment for toxicity or worse.
CBD use in animal health is a booming business. At the end of 2022, the global pet market for cannabidiol was valued at around AUD $302.2 million, with the market expected to grow by around 32 per cent each year from 2023 to 2030. By 2025, it is expected to be a $5 billion global industry.
CBD Vets Australia, a company that supports vets with education around legal medicinal cannabis treatment options, says for both pet owners and veterinarians alike, it is heartbreaking to see pets in pain and suffering from conditions because conventional treatments have fallen short.
“In these instances, many pet owners are wanting to explore alternative, natural therapies that may improve their pet’s quality of life,” a spokesperson says.
While it is difficult to provide exact figures on how many veterinarians across Australia regularly prescribe CBD as a treatment option, anecdotal evidence suggests awareness surrounding its use is increasing.
“[We see] this via the growing number of registered vets in our nationwide network and the increasing number of new prescriptions being written. Around 900 veterinarians across Australia currently prescribe with our network.”
Dr Jennifer Sandford, veterinary science liaison at PetCann, says due to the risks associated with not securing CBD oil through official channels, it is important that vets have a good understanding of CBD to ensure they can accurately advise and guide their clients. This is to guard against pet owners without a vet prescription purchasing CBD oil that contains impurities and other substances toxic to pets, such as heavy metals, chemicals pesticides or high amounts of THC.
Understanding how CBD—whether administered orally or topically—may mix with other medications is also critical, Dr Sandford says.
“Dogs and cats have complex physiology, just as humans do. Because of this, vets and pet owners need to be cautious when treating an animal with more than one substance as part of a treatment plan. CBD is metabolised in the liver via the cytochrome P450 enzyme system, which also metabolises a long list of other veterinary medicines. This means that if cannabidiol treatment is underway, other medications may need to be reviewed and potentially doses adjusted.”
Current regulatory framework dictates that in Australia, veterinary products containing cannabinoids must be registered as veterinary medicines.
To date, the Australian Pesticides and Veterinary Medicines Authority (APVMA) has not approved any veterinary chemical products containing cannabis.
Medicinal cannabis products with levels of THC above two per cent of the total cannabinoids in the formulation are Schedule 8 in the Poisons Standard and can only be prescribed by human health practitioners who are Authorised Prescribers.
Products containing CBD as the only cannabinoid are listed in the Poisons Standard under Schedule 4. To satisfy Schedule 4, the product must be 98 per cent or more CBD and contain no more than two per cent of other cannabinoids including THC.
In contrast, human medicinal cannabis products are often Schedule 8 and not allowed for pets.
In addition to complying with the provisions of Schedule 4 of the Poisons Standard, vets can only prescribe products for therapeutic use in animals manufactured outside of Australia. This is because the law dictates that cannabis-derived products manufactured in Australia are only approved for prescription to people, not animals.
In June the Australian Veterinary Association ratified its policy outlining its position on the potential use of CBD in animals. This states that while it supports the use of evidence-based principles when choosing treatments for animals, the use of medicinal cannabis in animals is an emerging area of veterinary medicine and the AVA recommends continued research into its use.
“There should be demonstrable benefits to justify choosing medicinal cannabinoids over the available registered medicines. Reasons may include the presence of multiple comorbidities needing management, the presence of contraindications to conventional medications or based on the veterinarian’s clinical experience and judgement.”
While early indications suggest CBD is “likely to be relatively safe” in animals, there is insufficient data on the risks associated with THC in animals, it says.
Dr Sandford concedes that when it comes to education around the use of CBD as a treatment option, challenges remain for vets in obtaining accurate information about legalities, dosage considerations and modes of action.
Dr Sandford, whose company provides CBD treatments for pets as well as education for vets on the topic, says the issue is complicated by the number of misconceptions that stem from CBD oil previously being illegal, and its recreational use.
“Many vets are concerned that pet owners may abuse the product recreationally, or that CBD could make pets high,” she says. “Neither of these are true. [As a trusted provider of CBD treatments], our firm abides by all legal requirements and has certificates of analysis for all products.
“If vets abide by the requirements, as set out by the APVMA, they are doing the right thing. Vets regularly prescribe ‘off label’ and compounded products. With support and education, more vets may be able to see that this is no different.”