- Elrod SM, Hofmeister EH. Veterinarians' attitudes towards use of nutraceuticals. Can J Vet Res. 2019 Oct;83(4):291-297. PMID: 31571730; PMCID: PMC6753883.
- Food Supplements. European Food Safety Authority. https://www.efsa.europa.eu/en/topics/topic/food-supplements. Consulted Sept 10th 2024.
- Williams, P.; Pettitt, R. Nutraceutical use in osteoarthritic canines: A review. Companion Anim. 2021, 26, 1–5.
- BVA companion animal feeding working group report. July 2024. https://www.bva.co.uk/media/5999/bva-companion-animal-feeding-working-group-report.pdf
- Finno CJ. Veterinary Pet Supplements and Nutraceuticals. Nutr Today. 2020 Mar-Apr;55(2):97-101. doi: 10.1097/nt.0000000000000399. PMID: 33446942; PMCID: PMC7802882.
- Barbeau-Grégoire M, Otis C, Cournoyer A, Moreau M, Lussier B, Troncy E. A 2022 Systematic Review and Meta-Analysis of Enriched Therapeutic Diets and Nutraceuticals in Canine and Feline Osteoarthritis. Int J Mol Sci. 2022 Sep 8;23(18):10384. doi: 10.3390/ijms231810384. PMID: 36142319; PMCID: PMC9499673.
- Deal CL, Moskowitz RW. Nutraceuticals as therapeutic agents in osteoarthritis. The role of glucosamine, chondroitin sulfate, and collagen hydrolysate. Rheum Dis Clin North Am. 1999 May;25(2):379-95. doi: 10.1016/s0889-857x(05)70074-0. PMID: 10356424.
- Bhathal A, Spryszak M, Louizos C, Frankel G. Glucosamine and chondroitin use in canines for osteoarthritis: A review. Open Vet J. 2017;7(1):36-49. doi: 10.4314/ovj.v7i1.6. Epub 2017 Feb 24. PMID: 28331832; PMCID: PMC5356289.
Discussing the use of dietary supplements with pet owners
As far as anthropomorphism can go, companion animal dietary supplements have experienced a rapid and significant growth in the recent years, supported by the perception of potential health benefits and improved well-being.
There is a now a plethora of products for owners to choose from, available through multiple channels and under many different forms.
For pet owners, giving a dietary supplement to their pet has a strong emotional meaning: it is a proof of their commitment to their pet’s health. But should pet owners be giving supplements, potentially at the expense of their animal welfare?
Is there a real need for dietary supplements when companion animals receive a complete, healthy and balanced diet?
With one vet out of two having clients sometimes requesting information about nutraceuticals1, veterinary surgeons and their support staff should be ready to have such discussion with pet owners. Below are a few pointers to guide vets and vet nurses through that conversation with pet owners.
What are dietary supplements and how are they regulated?
According to the European Food Safety Authority2, food supplements are concentrated sources of nutrients, that can be either minerals and vitamins or any other substances with a nutritional or physiological effect such as amino acids, essential fatty acids, fibre and various plants and herbal extracts. They are marketed with appropriate feeding guidelines and should be fed alongside the pet’s diet. They are not to be confused with nutraceuticals.
Nutraceuticals are food, or part of a food, that claims to provide medical or health benefits, including the prevention and/or treatment of a disease. Nutraceuticals and food supplements are often referred as dietary supplements.
In Europe, both nutraceuticals and food supplements are regulated as petfood. This has a very clear implication: pet dietary supplements are not drugs, as they do not cure, treat, prevent or mitigate a disease. In some cases, they can help support a specific condition.
More concretely, it is fair to say that veterinary dietary supplements are not subject to similar regulation as drugs, meaning that no evidence of efficacy has to be demonstrated in order to put them on market3. However, European pet food legislation regulates functional claims made on health benefits which go beyond the nutritional requirements. Furthermore , any pet food intended for particular nutritional purposes (‘dietetic’ pet food, such as for instance for ‘support of renal function in case of chronic renal insufficiency’ or ‘support of metabolism in joints in the case of osteoarthritis’) should comply with specific PARNUT legislation). It is the responsibility of the manufacturer to ensure that a food supplement placed on the market is safe. In addition to that, systematic reviews are still uncommon, making it difficult to evaluate existing products and make informed decisions about them3. Standardisation of reporting is needed to allow for more robust systematic reviews.
The importance of a complete and balanced diet
If a dog or a cat is fed a complete and balanced diet adapted to its life stage and/or health condition, theoretically there should not be any need for a food supplement , supplying extra nutrients. A complete diet, when given properly as per the manufacturer’s recommendations, is required to meet all nutritional requirements, including minerals and vitamins, appropriate to the life stage or the condition of the companion animal for which they are manufactured for4. Should there be a change in the condition or health of the animal, another appropriate diet should be chosen. Any additional intake, for instance under the form of a food supplement, could lead to exceeding recommended daily doses and could be toxic for the animal. Failure to adequately meet a pet’s nutritional needs can result in various health conditions (obesity, malnutrition, kidney, gastro-intestinal or dental diseases to name but a few).
With that said, choosing the right diet for a companion animal can be incredibly complex and challenging.
So, technically, if a pet has a complete and balanced diet, there is no need for a food supplement to supply additional nutrients. However, should there be a strong intent to get a dietary supplement, vets should feel confident to advise the pet owner with sound scientific evidence and have an open discussion to help them make informed decisions.
Recommending dietary supplements in the frame of contextualised care
Vets are in the best position to give advice to pet owners on the potential need for dietary supplements. As a matter of fact, one vet out of two regularly recommends nutraceuticals to patients1. They mostly do so at the request of pet owners (78%) or before the onset of a disease (73%)1.
If a pet owner wants a dietary supplement, the first thing to look at is the current diet, and the reason why the owner wants a dietary supplement.
- If the animal is fed a premium complete and balanced diet: there should not be any need for any food supplements, as the diet would cover all nutritional needs.
- If the animal is fed an unbalanced diet, whether it is a low-quality petfood or a home-made diet: switching to a more adequate, higher quality diet could be suggested.
- If the reason for asking about a dietary supplement is a clinical sign alerting the owner on his/her pet condition: then this medical condition needs to be properly investigated, diagnosed and treated by the vet.
The recommendation of dietary supplements should be made in the context of contextualised care. Omega-3 fatty acid products and glucosamine/chondroitin products are the most frequently recommended nutraceuticals to clients1 (respectively 94% and 93%) by vets, followed by multivitamins (24%) or specific vitamins (30%). Indeed, the condition for which vets feel nutraceuticals might be most useful is osteoarthritis, closely followed by dermatologic and gastrointestinal diseases1.
Pet dietary supplements can also be implemented alongside a robust therapeutic approach, especially in the specific context of chronic conditions such as atopic dermatitis or renal failure, where a long-term treatment and environmental measures are put in place. The use of food supplements in specific cases and following vet instructions can be a way of getting pet owners involved.
Choosing a pet dietary supplement
Care must be taken when choosing a dietary supplement, and only products that have been used in peer-reviewed clinical trials should be preferred. Efficacy, safety, and quality should be the main criteria for choosing a dietary supplement (Elrod,2019). However, due to the plethora of available products and the lack of regulatory framework, this data could prove difficult to find. There actually seems to be a lack of quality control, safety and efficacy data for most of the substances marketed in pet supplements5, making the task of taking informed decisions about pet supplements a challenge. There is a crucial need for more substantial evidence to supports claims of safety, efficacy and quality.
Efficacy can sometimes be difficult to prove based on scientific data, even though this can sometimes be seen in practice. Claims of efficacy for many pet food supplements and nutraceuticals are often based on subjective and non-rigorous assessments methods such as testimonials and should therefore be viewed with skepticism5.
There is recognised scientific efficacy of polyunsaturated fatty acids, particularly omega-36. Apart from recognised efficacy of omega-3, there is not always a lot of scientific proof of efficacy of dietary supplements. There are for instance contradictory studies out there on the efficacy of chondroitin / glucosamine nutraceuticals, despite proof of in-vitro anti-inflammatory effects on joints7 with some studies suggesting these products should no longer be recommended for pain management in canine and feline osteoarthritis6. The scarcity of well-designed clinical veterinary studies investigating the true treatment effect of glucosamine and chondroitin8, requires the need for further research to gain clarity on potential clinical benefits when using these agents.
Dietary supplements can be used to provide nutraceuticals, however some complete diets can also contain these compounds. When contemplating the use of a dietary supplement, it’s crucial to assess not only the quantity of the nutraceuticals in the supplement compared to the proven effective dose needed to achieve the claimed benefits, but also to take into account the amounts that may already be present in the diet.
Conclusion
Despite the lack of robust scientific published evidence on the safety, quality and efficacy of pet dietary supplements, their popularity recently exploded, following a similar trend in human health. It is essential that pet owners and vets have access to scientifically sound and unbiased sources of information to make informed decisions on the products they wish to use. Pet dietary supplements can sometimes be used in specific situations, following the vet recommendations. They should be carefully selected from reputable manufacturers based on available scientific published data and implemented within a situation of contextualised care.
Sources add