House Dust Mite Allergen in the GI Tract of Dogs with Chronic Enteropathy

In the Literature

Takahashi K, Yanuma N, Hirokawa M, et al. Presence of the house dust mite allergen in the gastrointestinal tract of dogs with chronic enteropathy: a potential inducer of interleukin-1β. Vet Immunol Immunopathol. 2020;230:110150.

The Research …

Chronic enteropathy in dogs is a group of disorders characterized by chronic, relapsing, inflammatory intestinal disease caused by dietary and/or environmental factors, the GI microbiome, and abnormal interactions with the immune system. Quality of life, digestion, absorption, and systemic health can be affected by chronic enteropathy.

This study evaluated the role of the house dust mite (HDM), a common environmental allergen, in allergic inflammation in the GI tract in dogs. The HDM allergen was quantified from gastric and duodenal fluids, feces, and duodenal and colonic mucosae of 24 healthy dogs and 38 dogs with chronic enteropathy. HDM allergen levels were significantly higher in dogs with chronic enteropathy as compared with healthy dogs. In addition, the HDM allergen was shown to increase both gene expression and protein levels of interleukin (IL)-1β in macrophages. Previous studies have shown a relative increase in this proinflammatory cytokine in the intestines of dogs with chronic enteropathy.¹ These results suggest that HDM allergens may be involved in the pathogenesis of chronic enteropathy by promoting IL-1β expression in GI macrophages.

… The Takeaways

Key pearls to put into practice:

• A thorough history with suspected chronic enteropathy should include all previous and current diets (including treats), all current and previous medications, information about the home environment and any outside activities (eg, visits to dog parks, daycare), travel history, any similar signs from other animals in the household, history of skin allergies, and any known previous GI infections or parasites. Previous adverse reactions to food, medications, or environmental allergens should also be noted, as this can help identify a trigger for chronic enteropathy.

• Endoscopic or surgical GI biopsies should be considered for definitive diagnosis in dogs unresponsive to hypoallergenic or novel protein diet trials, dogs with more severe clinical signs (eg, anorexia, weight loss, GI signs unresponsive to medications), older dogs, and dogs with hypoproteinemia, hypocobalaminemia, or suspected GI bleeding.

• The microbiome of the gut plays a significant role in host health and disease states. Dysbiosis is common in dogs with chronic enteropathy, and recognizing and treating dysbiosis may result in better long-term treatment success.