Dr Des Corrigan casts his eye over herbal remedies for pets and other animals
Reading a recent Irish Times business section feature on the potential of herbal medicine in veterinary practice made me realise that in all the articles I have written about herbs, I have never mentioned their use in domestic, farm or wild animals up to now. This got me thinking about what natural remedies could be used alongside conventional veterinary medicines.
The results of my desktop research, thanks to PubMed, were surprising and intriguing. A 2019 review in the Journal of Ethnopharmacology looked at research studies validating medicinal plants used in Canada for pet diseases and wild animals. Among the key conditions covered in the review and in other papers were sedation and anxiety, digestive issues, and also arthritis and joint pain.
When it comes to anxiety in pets, two well-known plants feature prominently, just as they do in human medicine. They are Valerian root and Passiflora (Passion Flower) herb. A specified dry extract of Valerian is recognised by the EMA as having a Well-Established Use as a herbal medicinal product for the relief of mild nervous tension and sleep disorders, based on human clinical trial evidence. Other extracts and the powdered root are recognised as traditional herbal medicinal products for the relief of mild symptoms of mental stress and to aid sleep because the evidence from clinical trials was deemed insufficient, although studies in animals support pharmacological plausibility.
A 2017 article in BMC Veterinary Research recommends the use of Valerian to enrich the quality of life of cats, especially if they are bored. The compound actinidine in Valerian triggers a positive response in 50 per cent of cats due to olfactory stimulation similar to that induced by catnip (Nepeta cataria), which was active in 66 per cent of cats tested.
Passiflora is also recognised by the EMA, having the same traditional indication claim as Valerian. It was not given WEU status because the numerous clinical trials were seen as being of low quality, but pre-clinical pharmacological studies in rodents did show sedative and anxiolytic effects.
While products containing either plant on its own or in combination would be obvious candidates for recommending to pet owners at Halloween in particular, the literature highlights other uses for the two herbal remedies. A 2022 paper in Animals looked at the use of the tranquilising effect of Passiflora as a way of preventing damaging tail biting by weanling pigs. Compared to a control group, those piglets given Passiflora had significantly fewer ear lesions, exhibited less-aggressive behaviour, and had lower cortisol levels.
Weight gain was similar in both groups, whereas a 2017 study in Applied Animal Behavioural Science found that pigs given a mixture of Valerian and Passiflora showed a significant rise in body weight compared to controls that was attributed to the tranquilising effect of the plants which reduced aggression, thereby transferring energy to growth rather than negative behaviour.
A 2026 paper in Frontiers in Veterinary Science investigated the composition and effect of a proprietary multi-component natural veterinary medicinal product used to reduce stress in horses, pigs, goats, sheep, dogs and cats. This product consists of a mixture of early-stage homeopathic dilutions (D2) of extracts of Passiflora, oats, coffee and the zinc salt of isovalerenic acid – a constituent of valerian. Even though they are diluted, they still contained measurable quantities of key chemicals upon analysis. The product was tested in Siberian sled dogs undergoing rigorous race training, resulting in a significant reduction in exercise-induced cortisol and gastrin levels.
Passiflora also featured in a 2025 article in the same journal that evaluated the efficacy of a nutraceutical supplement also containing both the adaptogen Withania (Ashwagandha) and dandelion on inflammatory markers and oxidative stress in older dogs. These were given the supplement for 40 days, resulting in significant reductions in the levels of CRP and IL-6 and IL-10 cytokines compared to baseline, as well as an increase in total antioxidant activity. The researchers also concluded that quality of life improved in the seven ageing dogs.
These findings are particularly significant because the literature suggests that 20 per cent of pet dogs and 93 per cent of cats develop osteoarthritis based on US figures. Thus, there is a lot of interest in alternatives to standard NSAIDs. Extracts from plants such as Devil’s Claw, frankincense (Boswellia) and turmeric that are known to be effective in humans with osteoarthritis are obvious candidates for inclusion in pet remedies. Another natural but non-plant option that has received much research attention is the Green-Lipped Mussel (GLM) from New Zealand.
Several clinical trials in domestic pets with osteoarthritis have been published
Freeze-dried powdered mussel or an oil extract of it contains a mixture of bioactive lipids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), known to inhibit both COX and LOX cascades of arachidonic acid metabolism. According to a 2021 systematic review in Inflammopharmacology, based on nine human studies involving 452 participants with radiologically confirmed osteoarthritis of the hip or knee, GLM extracts provided moderate and clinically-significant effects on a VAS pain scale and improved GIT symptoms in patients taking anti-inflammatory medicines.
Several clinical trials in domestic pets with osteoarthritis have been published. In a 2009 RCT published in the journal ECAM, a GLM product showed significant improvement in veterinarian-assessed mobility and a pain VAS evaluated by owners of 45 dogs with a radiographic diagnosis compared to placebo, but it was not as effective as carprofen.
The Canadian Journal of Veterinary Research in 2013 reported on a trial with 23 dogs with osteoarthritis given a control diet for 30 days followed by a GLM-enriched one for 60 days. The gold standard for assessing osteoarthritis in dogs is apparently Peak Vertical Force (PVF), which improved significantly after GLM but showed no change after the control diet. Owner-assessed pain questionnaires and motor activity also significantly improved between day 0 and day 90.
Less-favourable results were reported from a 2022 study in Veterinary Medicine and Science, in which 32 dogs and 16 cats were enrolled in a double blind, randomised crossover trial for 10 weeks in cats and 16 weeks in dogs, where they were treated with a supplement containing GLM, curcumin and blackcurrant leaf extract.
Only partially positive effects in both species were reported by both owners and veterinarians. An industry-funded RCT comparing the efficacy of a proprietary product containing GLM plus krill oil extract with meloxicam in 101 dogs appeared in Frontiers in Veterinary Science in 2024. After six weeks, the PVF values as a percentage of body weight were significantly greater than at baseline for both the supplement and the meloxicam compared to placebo.
In addition, the lowest orthopaedic assessment scores, signifying reduced impairment, were also in the GLM/krill and meloxicam groups. That same year a study in Veterinary Record suggested that GLM extracts in the diet of aged non-domestic cats kept in captivity (tigers, etc) resulted in them taking significantly more steps per minute.
On the basis of the evidence, there is clear potential in this area and it might be worthwhile for both urban and rural pharmacists to take a more detailed look at what might turn out to be a positive revenue stream.
