Oftentimes companion pet parents wonder about the cause of our companion pets scratching. Is it a seasonal allergen? Is it a food sensitivity? Is it an environmental allergen? Of course, many of us think “environmental” refers to the outdoor environment. We often forget that indoor allergens are also environmental. A quick Google search of “indoor allergens” elicited indoor common air allergens such as mold, pet dander, house plants, and dust.
Overlooked Allergens
So, what are the oft forgotten, overlooked allergens? Indoor contact allergens, which would also be categorized as environmental. An August 2022 South Korean study demonstrated that 31.2% of companion dogs had an allergy to animal wool and 41.8% of them reacted to oak. This study used the serological enzyme-linked immunoassay (ELISA) kits that measure for IgE-specific allergen.
The IgE allergen test is the gold standard for measuring allergic reactions to environmental and seasonal allergens. The IgE allergen test also can be applied to food. However, actual food allergies are hypersensitivities and quite rare. Food sensitivities or intolerances, however, are actually quite common and measuring the mucosal surface antibodies, IgA and IgM, are the better predictors to determine a sensitivity to food. As Elizabeth Bobeck, Ph.D. of Iowa State University stated, “gastrointestinal immune system, the first population of immune cells with direct dietary interaction, the organization is such that the intestinal lumen contains secretory immunoglobulin A (IgA) antibodies.” Hemopet’s NutriScan Food Sensitivity & Intolerance Test measures the secretory IgA antibodies in saliva.
Food Allergy or Food Sensitivity?
The discussion below will clear up any confusion between food allergy and food sensitivity.
Food allergies reflect a more immediate immunological response. A classic example of a food allergy is anaphylactic shock caused by peanuts: as soon as the person or animal comes in contact with the allergen – the peanuts – their airway closes and they cannot breathe. This response is virtually instantaneous. Boom! The antigen (in this case, peanuts) triggers an immediate, and sometimes life-threatening, immunological and physiological reaction. Rashes, hives and swollen eyes are examples of less severe – but also serious – allergic responses. These are all called Type I hypersensitivity reactions. In the blood, they show up as antibodies to IgE and IgD, IgG working together with immune complexes.
A food sensitivity, on the other hand, is an intolerance to one or more foods and typically is a chronic condition and often does not involve an immunological response. It generally builds up over time – perhaps even after months or years of exposure to the offending food. Food sensitivity is caused by Types II and III hypersensitivity reactions. They show up in saliva or feces as antibodies to IgA and IgM. By detecting IgA and IgM antibodies, food sensitivity testing is able to clearly identify the specific food(s) causing the skin sensitivity or gastrointestinal intolerance. It can also differentiate between food sensitivity and food allergy.
References
Adam, Gareeballah Osman et al. “Detecting common allergens in dogs with atopic dermatitis in South Korean Provinces using a serological immunoglobulin E-specific allergen test.” Veterinary world vol. 15,8 (2022): 1996-2003. doi:10.14202/vetworld.2022.1996-2003, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9615500/.
Bobeck, Elizabeth Ann. “NUTRITION AND HEALTH: COMPANION ANIMAL APPLICATIONS: Functional nutrition in livestock and companion animals to modulate the immune response.” Journal of animal science vol. 98,3 (2020): skaa035. doi:10.1093/jas/skaa035, https://academic.oup.com/jas/article/98/3/skaa035/5728573.