Mucosal defence along the gastrointestinal tract of cats and dogs

Abstract

-Diseases that are associated with infections or allergic reactions in the gastrointestinal and respiratory tracts are major causes of morbidity in both cats and dogs. Future strategies for the control of these conditions require a greater understanding of the cellular and molecular mechanisms involved in the induction and regulation of responses at the mucosal surfaces. Historically, the majority of the fundamental studies have been carried out in rodents or with tissues obtained from man, but the expanding range of reagents available for the study of farm and companion animals provides opportunities for study in a wider range of animals including cats and dogs. To date, these studies have tended to be focussed on characterising the cellular distributions in healthy animals and in groups of cats and dogs identified as having an increased risk of mucosal disturbance. Where species comparisons of mucosal immune systems have been made, the results have tended to be divided between monogastric and ruminant animals. It is then not surprising that the mucosal immune systems of both cats and dogs bear greatest similarity to that documented for man and pigs.

Effect of cognitive enrichment on behavior, mucosal immunity and upper respiratory disease of shelter cats rated as frustrated on arrival

“…Elevated S-IgA has consistently been reported to protect against URD in many species (Hewson-Bower and Drummond, 1996;Brandtzaeg, 2003;Stokes and Waly, 2006;Flies et al, 2012), and conversely IgA deficiency has been associated with persistent symptoms of URD (Brandtzaeg et al, 1987;Renegar and Small, 1991;Janzi et al, 2009). However, in a study of IgA knockout mice (IgA-/-) generated by gene targeting, IgA was not required for prevention of influenza virus infection and disease, indicating that other Ig's may serve to decrease susceptibility to URD (Mbawuike et al, 1999).…”

“…In relation to this, it has been associated with a decrease in secretion of immunoglobulin A (s-IgA) in shelter cats (Gourkow et al 2014a). S-IgA is the most abundant mucosal antibody and is necessary for protection against pathogens that are inhaled or ingested (Stokes and Waly, 2006), particularly in multi-cat environments where such pathogens are found in high concentration (Pedersen et al, 2004). When induced by electrostimulation of the anteromedial hypothalamus, frustration (labelled as restlessness by the authors) had important pathophysiological and immunological effects such as elevated cortisol and cathecolamine, arrhythmia, increased responses of lymphocytes to phytohemagglutinin (Mori et al, 2001), and gastric and cardiac lesions (Kojima et al, 1996).…”

Phenotyping, functional characterization, and developmental changes in canine intestinal intraepithelial lymphocytes

“…To protect the body from invading pathogens, the intestinal mucosa has developed one of the largest and most complex organ-associated immune systems [19]. Under normal physiological conditions, the intestinal immune system is tightly regulated to avoid overshooting reactions.…”

“…Loss of this regulatory control mechanism in inflammatory bowel disease (IBD) leads to perpetuating inflammatory and infiltrative responses. In both humans and dogs, the development of intestinal mucosal inflammatory disorders, such as IBD, is observed with increasing frequency [19]. Despite the high incidence of IBD in dogs, the mechanistic events leading to these disease entities are poorly understood.…”

Emotions, mucosal immunity and respiratory disease in shelter cats

“…However, these findings were replicated with similar results [67,68] and built upon by evidence that humoral immunity could also be behaviourally conditioned [69]. These data support the hypothesis that stress hormones are key regulators of immune response.…”