Canine eosinophilic gastrointestinal disorders

Abstract

Eosinophils play a crucial role in the inflammatory response in conjunction with both innate and adaptive immunity. Eosinophils have long been recognized as inflammatory leukocytes that are particularly important in patients with parasitic infestations. However, recent studies in veterinary medicine demonstrate a number of canine eosinophilic gastrointestinal (GI) disorders unrelated to a parasitic infestation. Although the underlying pathophysiology behind eosinophilic infiltration of the canine GI tract remains uncertain, medical intervention aiming to decrease the activation of eosinophils seems effective in reducing symptoms and preventing organ damage. This review focuses on the biology of eosinophils and their products. It describes, the composition of eosinophil granules, mechanisms of eosinophil activation, and eosinophil-related disease processes leading to organ damage. Even though the main clinical signs of canine eosinophilic gastroenteritis, vomiting and diarrhea, are similar to those of other types of gastroenteritis, the clinical response and prognosis are worse for this condition. The clinical signs and diagnostic approach for eosinophilic GI disorders are described and compared between canine and human patients for each region of GI tract, from the esophagus to the colon. Moreover, the current treatments for this syndrome in canine and human patients are summarized and paralleled. The comparative study of canine and human patients with eosinophilic gastroenteritis will advance the understanding of this syndrome in both species and may lead to the development of novel treatment strategies.

Assessment of eosinophils in gastrointestinal inflammatory disease of dogs

“…Abnormal accumulation of eosinophils in the intestine in the absence of other underlying causes (eg, parasitic infections) is a characteristic feature of EGID, including IBD 4, 19. Staining of duodenal biopsy specimens with H&E for histopathological evaluation is routinely performed during diagnosis of IBD in dogs 13, 14.…”

“…Eosinophils play a crucial role in innate and adaptive immunity of the GI tract by participating in host defense against luminal pathogens and maintaining intestinal epithelial homeostasis 3, 4, 5. In dogs, IBD is the term used to describe persistent or recurrent GI signs (eg, weight loss, vomiting, and diarrhea) and histopathological evidence of intestinal inflammation without underlying causes (eg, infection, endocrine, and neoplastic disease) 6, 7.…”

“…Therefore, it is important to accurately detect not only intact eosinophils with intracellular granule proteins but also extracellular release of granule proteins by activated eosinophils, to obtain a better understanding of the contribution of eosinophil activation to disease pathogenesis. The pathophysiological effects associated with eosinophilic infiltration of the GI tract remain poorly defined 4. Histological evaluation of endoscopic biopsy specimens is performed frequently in the diagnosis and management of dogs with IBD.…”

Gastritis and Peptic Ulcer Diseases in Dogs: A Review

“…Diffuse form of EG has Scirrhous inflammatory thickening on the gastric wall that resembles with gastric neoplasia (Hayden and Fleischman, 1977;Neiger, 2008;Lidbury et al, 2009). Genetic predisposition and diet are noticed for pathogenesis (Sattasathuchana and Steiner, 2014) but some factors like gastric parasitic infestation by Physaloptera spp. (Neiger, 2008), Gnathostoma spp.…”

Evaluation of Serum 3‐Bromotyrosine Concentrations in Dogs with Steroid‐Responsive Diarrhea and Food‐Responsive Diarrhea

“…Neutrophilic enteritis, granulomatous colitis, and histiocytic ulcerative colitis also have been reported as minor forms of histopathologic findings in dogs with CE . An immune response to parasites or to dietary antigens is believed to be the cause of the recruitment of eosinophils into the GI tract …”