Fridays with Finn

An Equine Nutrition Blog

When to Add Supplements

By: Madeline Boast, MSc. Equine Nutrition

The Supplement Industry

The equine supplement industry is wild! There are an overwhelming number of options, and there seems to be a supplement for just about everything. As a horse owner, it can be challenging to know which ones are worth the money and which simply aren’t. Research has estimated that over 80% of horse owners include at least one dietary supplement in their horse’s nutrition program. Unfortunately, it is rare that these decisions are made based on the research. It is more common that it is great advertising or anecdotal evidence.

There are multiple publications that try to quantify the perceptions of horse owners regarding dietary supplements. One study found that over 90% of the respondents thought that all supplements were tested on horses prior to being launched on the market. Although that would be ideal, the equine nutraceutical industry is not that well-regulated.

Dr. Wendy Pearson of the University of Guelph has focused a significant amount of her career on equine nutraceutical research (she was also my MSc. advisor!!). This is a published quote from her that I think encapsulates the supplement industry well: “The voracious appetite of horse owners and managers for these supplements has vastly outpaced research into equine-specific efficacy, safety or toxicity of the majority of available products”.


Nutrient Requirements and Supplements

The NRC, 2007 provides nutritionists with the basic nutrient requirements for horses. This includes energy, protein, fat, as well as various vitamins and minerals. Every horse should be on a diet that meets these baseline requirements.

Once this baseline is met, knowing what the research says about therapeutic doses is important. For example, if you have your horse on a balanced diet, but their hoof health is still not adequate then adding biotin has been shown to help. However, you need to ensure you are adding a therapeutic dose.

To simplify the process, I have divided my recommended process into a few steps.

STEP 1: Have a nutritionist test your hay to ensure your horse is on a balanced diet.

STEP 2: Discuss your nutritional concerns with your nutritionist e.g., hoof health, gut health, joint health etc. From there, your nutritionist can use their expertise to recommend a supplement.

This is one of the reasons I don’t offer supplement recommendation packages. The whole picture is extremely important, and in my professional opinion as a qualified equine nutritionist, accurate supplement recommendations should be made based on a balanced diet with a hay analysis.

So then, what is my process for recommending supplements?

My process is simple, I always turn to research. You would be surprised at how many popular supplements have no concrete research supporting their efficacy. Using the nutritional analysis breakdown to compare the concentrations of active ingredients can also be a helpful tactic. Therefore, my approach has three key steps:

1)      Do a full consultation to ensure I have the whole picture prior to making recommendations.

2)      Evaluate the completed and published research on the supplements.

3)      Compare the concentration of active ingredients in the products.


Comparing Supplements

Here are a few examples of some popular supplements being compared based on their active ingredient concentrations:

These four supplements are all popular, and I see them commonly used in equine diets here in Ontario. However, you can clearly see that they are not equal. When directly compared on equivalent weight doses it is evident which supplement is more valuable based on the chosen active ingredient. These simple comparisons ensure that you are not being influenced by good marketing and that your money is being spent well. At the end of the day, if you are spending money on supplements, and putting the extra effort in to feed them – you should put the time in to make sure it is the best possible option for your horse.


The Research

When browsing websites of supplement brands, some are fantastic and others…well not so much. I personally like when the citation to the published research is included on the supplement page. What I am not a fan of is when there is anecdotal evidence made to seem like it was a proper research study. Occasionally, I will be reading pages like this and realize that their “study” didn’t even have a control group!!

A supplement you are probably familiar with is the KER EO3 by Kentucky Equine Research. This supplement has had in vivo research done which has been able to show positive differences between a group of horses consuming this supplement and a group consuming flax oil: “the study clearly demonstrates that daily intake of EPA and DHA from KER EO-3 significantly increases red blood cell membrane EPA and DHA but that a similar amount of omega-3 in the form of ALA from flax oil does not”.

Another example is the supplement Breathe by Herbs for Horses. This supplement has also had in vivo research done. Through this research, they illustrated that the product was able to safely reduce the elevated respiratory rate in horses with recurrent airway obstruction.

A third example (because why not, research is fun!!) is a recent in vitro study with the Equine Omega Complete supplement. This study investigated the anti-inflammatory as well as chondroprotective effects of the supplement on stimulated cartilage explants. Their findings were that the supplement did prevent a significant increase in net GAG loss when the cartilage was stimulated and therefore supported the use of Equine Omega Complete. Further research is required to prove efficacy in horses, as swine cartilage was used in the study.

These citations are listed in the reference list if you’re interested in reading more! I would like to make a note that these are a couple of the available studies and just because they are included in this blog post does not mean they are optimal for your horse. Every horse is unique, and at Balanced Bay each balanced diet is personalized to optimally support their individual needs. If you have any questions or would like to optimize your horse’s diet, please contact Madeline at 

Overall, supplements can be and are often a fantastic addition to the equine diet when there are specific nutritional concerns. However, it is worthwhile spending the money on expert advice to ensure you are getting what you’re paying for.


Garland, A., Wierenga, C., McCrae, P., & Pearson, W. (2023). Cartilage-sparing properties of Equine Omega Complete in an organ culture model of cartilage inflammation. Journal of Equine Veterinary Science, 121, 104165.

Hoffman, C. J., Costa, L. R., & Freeman, L. M. (2009). Survey of feeding practices, supplement use, and knowledge of equine nutrition among a subpopulation of horse owners in New England. Journal of Equine Veterinary Science, 29(10), 719-726.

Murray, J. A. M., Bloxham, C., Kulifay, J., Stevenson, A., & Roberts, J. (2015). Equine nutrition: a survey of perceptions and practices of horse owners undertaking a massive open online course in equine nutrition. Journal of Equine Veterinary Science, 35(6), 510-517.

Murray, J. M. D., Hanna, E., & Hastie, P. (2018). Equine dietary supplements: an insight into their use and perceptions in the Irish equine industry. Irish veterinary journal, 71(1), 1-6.

Pearson, W. (2021). 127 Equine Nutraceuticals: Is Science Finally Catching up to Fiction?. Journal of Animal Science, 99(Suppl 3), 66.

Pearson, W., Charch, A., Brewer, D., & Clarke, A. F. (2007). Pilot study investigating the ability of an herbal composite to alleviate clinical signs of respiratory dysfunction in horses with recurrent airway obstruction. Canadian journal of veterinary research, 71(2), 145.

Rexford, J. K. (2010). Effects of two different dietary sources of omega-3 highly unsaturated fatty acids fatty acids on insulin sensitivity, and incorporation into the plasma, red blood cell, and muscle cell in horses (Doctoral dissertation, Colorado State University).


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