Flaxseed for Pets

The humanization of pets has led to demand for pet food products mirroring trends in human health food.¹ Trends such as “non-GMO,” “grain-free,” “human-grade,” “sustainable,” and more, are taking off.¹ Omega-3 fatty acids have a role to play in this market. Increasing omega-3 fatty acid content in pet food will resonate with consumers and improve pet wellbeing by offering holistic health benefits.

Horses

The Benefits of Flaxseed in Equine Diets

A study² in the Canadian Journal of Veterinary Research examined the effect of flaxseed supplementation on the skin test response of atopic horses. This was a small study involving six horses that tested positive for an allergy to an extract from Culicoides sp. (commonly referred to as midges) which causes a condition known as pruritus, or “sweet itch.” This skin condition affects tens of thousands of horses every year in North America and Europe.²

Method: The study was a 42-day, placebo-controlled, double-blind, cross-over trial. Group A included 3 randomly selected horses which were fed 1 lb. of milled flaxseed per 1000 lbs. of body weight for 42 days. The milled flaxseed was supplied by Pizzey Ingredients. Group B (Placebo) consisted of 3 randomly selected horses that were fed 1 lb. of bran per 1000 lbs. of body weight for 42 days. At the end of the 42-day trial period, the horses went 14 days with no supplements and then crossed over and the trial repeated. On days 0, 21, and 42 of the experiment, each horse received an injection of Culicoides extract, saline (negative control), and histamine (positive control) in 3 separate spots approximately 25 mm apart.

Results: The saline showed no reaction to the flaxseed diet or the placebo. The Culicoides and histamine injection sites did show a reaction. On day 42, the Culicoides showed a significant reaction in the treatment group. However, this did not appear on days 0 or 21. The reaction area to the Culicoides injection was less for the group that received flaxseed than for the group that received the placebo (bran).

Conclusion: This study indicates that supplementing a horse’s diet with milled flaxseed may reduce allergic skin response to Culicoides extract. Because this study was conducted in a very small sample size, more research needs to be done to confirm these results.

A study³ looking at the effects of soybean oil or flaxseed oil on the plasma biochemical indices, hematological parameters, and redox status in horses found that horses supplemented with flaxseed oil had significantly lower levels of glucose, low density lipoprotein cholesterol, and triacylglycerols. Furthermore, horses in the flaxseed oil group showed increases in antioxidant indices such as creatinine, vitamin C, copper, and zinc as well as significantly lower levels of malonyl dialdehyde which is a product of lipid peroxidation. This suggests that flaxseed oil may have positive effects on the lipid profile and antioxidant activity in horses compared to other vegetable oils.

Another study⁴ published in Horse Feeding and Management, found that linseed-groat based supplements combined with other soluble fiber sources improved crude protein and fat digestibility and can be used to replace grains in the diet of horses without affecting horse health. This is valuable information because high starch diets lead to gastric ulcers which is a frequent problem encountered by horse owners. Replacing grains with flaxseed may improve horse health and mitigate gastric ulcers.

Omega-3 and omega-6 fatty acids are found in grass—a horse’s natural diet. However, during the curing process, fatty acids naturally found in hay are depleted.⁵ Thus, it is important that horses are supplemented with omega-3 and omega-6 fatty acids. Furthermore, short-chain fatty acids (SCFAs) may help in gut health and prevention of gastric ulcers.⁵ Short-chain fatty acids including acetic acid, propionic acid, and butyric acid are produced in the gut of horses. Flaxseed is one of the best ways to add these SCFAs into a horse’s diet as it has the highest omega-3 to omega-6 ratio of any plant.⁵

Dogs

The Benefits of Flaxseed for Dogs

Just as in humans, a high omega-6:3 ratio may create an inflammatory state in dogs.⁶ Flaxseed, which is rich in alpha-linolenic acid (ALA) and has an impressive omega 6:3 ratio, can help reduce inflammation by increasing the omega-3 index. This has the potential to improve diseases related to inflammation such as cancer, skin disorders, cardiovascular disease, arthritis, and more.¹

A high omega-3 index can lead to a better conversion rate of ALA to eicosapentaenoic acid (EPA) and docosapentaenoic acid (DHA) since linoleic acid (LA), a type of omega-6 fatty acid, competes with ALA for conversion enzymes. According to Jennifer Adolphe, PhD, RD, Senior Nutritionist at Petcurean, DHA is of particular importance in gestation and growth of dogs, and newborn puppies preferentially convert ALA into DHA which suggests that the enzymes required for this conversion are more active early in life. To increase ALA supplementation in young dogs, flaxseed can be given to the mother so that ALA is passed to her puppies via milk. One study involving dogs fed either ground sunflower seed (9.3% of calories from LA and 0.4% from ALA) or ground flaxseed (7.3% calories from LA and 2.5% from ALA) for 84 days recorded rapid accumulation of EPA after 4 days on the flaxseed diet.⁸ EPA levels reached a steady level after 28 days. Researchers also detected DPA which is a precursor to DHA in dogs. However, no DHA was found in the plasma. It is speculated that DPA could possibly be transported to nerve tissues (the retina for example) where it is converted into DHA.

Flaxseed has been shown to improve clinical scores of canine atopic dermatitis. A double-blinded, placebo-controlled, randomized trial involving 29 dogs found that dogs given flaxseed oil or a commercial preparation of EPA and DHA had improved clinical scores for canine atopic dermatitis whereas the placebo group (mineral oil) showed no improvement.⁹ Other studies have shown that a diet rich in EPA lowers clinical scores for atopic dermatitis in dogs.⁶ Furthermore, in dogs, the conversion of ALA to EPA is sufficient and pre-formed EPA is not usually necessary.⁶ This means flaxseed has the potential to significantly improve atopic dermatitis symptoms in dogs.

Notes

1.      Jennifer Adolphe, PhD, RD, Kelley Fitzpatrick, MSc., “Flaxseed: A Nutrient-Packed Ingredient for Pet Food,” Flax Council of Canada 1.
2.      Wendy O’Neill, Sharyn McKee, Andrew Clarke, “Flaxseed (Linum usitatissimum) supplementation associated with reduced skin test lesional area in horses with Culicoides sp. sensitivity,” The Canadian Journal of Veterinary Research 66, no. 4 (2002): 272-7. https://www.researchgate.net/publication/11046795
3.      Iwona Sembratowicz, Grzegorz Zięba, Ewelina Cholewinska, Anna Czech. “Effect of Dietary Flaxseed Oil Supplementation on the Redox Status, Haematological and Biochemical Parameters of Horses’ Blood,” Animals (Basel) 10, no. 12 (2020): 22-44, doi: 10.3390/ani10122244
4.      Markku Saastamoinen, Susanna Särkijärvi, “Effect of Linseed (Linum usitatissimum) Groats-Based Mixed Feed Supplements on Diet Nutrient Digestibility and Blood Parameters of Horses,” Animals10, no. 2 (2020): 272, doi: 10.3390/ani10020272
5.      Dr. Richard McCormick, M.V.B., Dip. Eq. Sc., M.R.C.V.S, “Trust your gut—the importance of feeding the gut microbiome for health, performance & longevity,” Trainer Magazine, April 04, 2024, https://trainermagazine.com/european-trainer-articles/tag/flaxseed
6.      Anton Beynen, “Omega 6-3 ratio in dog food,” ResearchGate. May 2020. https://www.researchgate.net/publication/341286652_Beynen_AC_2020_Omega_6-3_ratio_in_dog_food
7.      Jennifer Adolphe, “Flaxseed: Omega 3 Benefits for Dogs and Cats.” FlaxResearch.com, June 19, 2016, https://flaxresearch.com/2016/06/flaxseed-omega-3-benefits-dogs-cats/
8.      Bauer, J.E., DVM, PhD, DACVN. “Responses of dogs to dietary omega-3 fatty acids.” AVMA Publications 231, no. 11 (2007), doi: 10.2460/javma.231.11.1657
9.      R.S. Mueller, K. V. Fieseler, M.J. Fettman, S. Zabel, R. A. W. Rosychuk, G.K. Ogilvie, T. L. Greenwalt, “Effect of omega-3 fatty acids on canine atopic dermatitis,” Journal of Small Animal Practice 45, no. 6 (2004): 293-297, doi: 10.111/j.1748-5827.2004.tb00238.x