Food intolerance in dogs

Adverse food reactions are defined as abnormal response to an ingested food or food additive⁵. Based on pathomechanisms, these adverse food reactions can be subclassified further to food allergy/food hypersensitivity and food intolerance^{4, 5}.

While food allergy and food hypersensitivity refer to an adverse food reaction due to an immunologic mechanism, food intolerance refer to an adverse food reaction due to non-immunologic mechanisms^{2, 3, 4, 5, 6}. Food allergy/food hypersensitivity is a reaction caused by antibody-, immune complex-, or cell-mediated-immune reactions². Food intolerances may be caused by pharmacological reactions to dietary ingredients^{2, 4} such as histidine in fish transformed into histamine by the intestinal microbiota⁴, by a metabolic problem such as lack of intestinal enzymes (eg, lactase) ^{2, 4}, or dysmotility, dysbiosis, physical effects and non-specific dietary sensitivity³. Ingredients known to be associated with food intolerance is for example lactose and gluten⁷. Gluten-sensitive enteropathy is described in Irish Setter dogs^1,4.

This terminology, regarding adverse food reactions, has been used in small animal clinical nutrition for over 20 years. Traditionally, food allergy and food hypersensitivity were used to describe all kinds of adverse food reactions in dogs and cats including food intolerances⁴.

By Klara N. Trads DVM and Technical Manager at Bacterfield GMBH

References:

1. Batt R.M. and Hall E.J. (1992): Dietary modulation of gluten sensitivity in a naturally occurring enteropathy of Irish Setter dogs. Gut, 33: 198-205.
2. Case L.P., Carey D.P., Hirakawa D.A., Daristotle L. (2000): Canine and Feline Nutrition. 2nd Edition. Mosby Inc, Missouri, United States of America.
3. Craig JM. Food intolerance in dogs and cats. J Small Anim Pract. (2019) Feb;60(2):77-85
4. Gaschen F.P. Sandra R. Merchant S.R., Adverse Food Reactions in Dogs and Cats, Veterinary Clinics of North America: Small Animal Practice (2011) Volume 41, Issue 2, Pages 361-379
5. Hand, M.S., Thatcher, C.D. Remillard R.L., Roudebush P. and Novotny B.J. (2000): Small Animal Clinical Nutrition. 4th Edition. Mark Morris Institute, Kansas, United States of America.
6. Verlinden A, Hesta M, Millet S, Janssens GP. Food allergy in dogs and cats: a review. Crit Rev Food Sci Nutr. (2006) 46(3):259-73 7. Zoran D. Nutritional management of gastrointestinal disease. Clin Tech Small Anim Pract. (2003) 18(4):211-217.