Inflammatory Bowel Disease Dogs Research Articles

Serum D-Lactate Concentrations in Dogs with Inflammatory Bowel Disease.

The D-enantiomer of lactic acid (D-lactate) is normally produced from bacterial fermentation in the gastrointestinal tract in mammals. In humans, increased D-lactate concentrations are related to gastrointestinal disease, including short bowel syndrome and malabsorptive syndrome. Similarly, increased D-lactate concentrations have been described in calves affected by diarrhea, in cats with gastrointestinal diseases, and in dogs with parvoviral enteritis. The purpose of the present study was to measure the serum D-lactate concentrations in dogs with inflammatory bowel disease (IBD). We retrospectively reviewed data from the database of the VTH of Perugia University, and dogs affected by IBD with serum samples stored at -80 °C were considered eligible for inclusion. A total of 18 dogs with IBD and 10 healthy dogs were included in the study. The dogs with IBD were divided into three subcategories based on the severity of the disease. Serum D-lactate concentrations (μM) were determined using a commercially available colorimetric assay kit (D-Lactate Colorimetric Assay Kit; Catalog #K667-100, BioVision Inc., Milpitas, CA, USA). Our results showed no significant difference (p > 0.05) in the serum concentrations of D-lactate between dogs with various degrees of IBD and healthy dogs. However, the wide variability of the D-lactate concentrations in dogs with IBD and evidence of increased serum D-lactate concentrations in dogs with confirmed dysbiosis encourage further studies on this topic to understand potential factors influencing the serum D-lactate concentrations in dogs affected by IBD.

Assessing the Quality of Life of Dogs with Inflammatory Bowel Disease and Their Owners.

The aim of the study was to assess the quality of life (QoL) of dogs with inflammatory bowel disease (IBD) and the impact on the life and relationship of the owner. An online questionnaire based on a Likert scale score (1-10) was designed to assess items related to dog QoL, owner QoL, and the owner-dog relationship. Responses from 110 dog owners (30 with IBD and 80 healthy dogs) were included in the study. IBD dogs had significantly lower overall QoL (p < 0.001), health (p < 0.0001), and level of activity (p = 0.049). Owners of dogs with IBD reported lower overall QoL (p < 0.001). The scores for how their dog's QoL might affect their own QoL (p = 0.028), how much their dog limited their social life, leisure time, or daily activities (p = 0.015), and how often they felt burdened by caring for their dog (p = 0.006) were significantly higher in the IBD group when compared to the healthy group. In addition, IBD dog owners were more likely to see their dogs as children (p = 0.0004). IBD has a negative impact on affected dogs and their owners regardless of the severity of the disease.

An endoscopic and histopathological assessment and correlation of endoscopic score with clinical activity index (CIBDAI) in the diagnosis of canine idiopathic inflammatory bowel disease.

Inflammatory bowel disease (IBD) in dogs is often characterized by a relapsing and remitting clinical course. Determination of inflammatory activity is important for assessing the disease extent, severity, and tailoring appropriate treatment. The study was conducted to record the macroscopic and microscopic changes associated with IBD to assess the usefulness of endoscopy in the diagnosis of the disease and to correlate the clinical activity index (CIBDAI) with endoscopic score. Thirty-three dogs with idiopathic IBD were selected after thorough examination and exclusion. Gastroduodenoscopy and colonoscopy were performed to document the gross macroscopic intestinal lesions. Histopathology of endoscopic aided biopsy samples was used to confirm the disease. Mucosal erythema and increased friability were the most predominant endoscopic findings in the stomach, duodenum, and colon of IBD dogs. Lymphoplasmacytic infiltration was predominant in the mucosal samples on histopathology and diffuse form of IBD is more common in canines. Gastroduodenoscopy and colonoscopy in combination with endoscopically guided biopsy and histopathology are of value in the assessment and diagnosis of IBD. There was no correlation between the clinical inflammatory bowel disease activity index (CIBDAI) with the endoscopic score. A diffuse form of IBD and colitis is more common in dogs in comparison to human IBD where the disease manifests in two distinct forms. Colonoscopy with ileal biopsy could act as a gold standard in the confirmation of diffuse IBD in dogs. CIBDAI can be used as a reliable measure of clinical signs of inflammation and histopathology can be used as a definitive diagnosis of intestinal inflammation.

Clinical signs, duodenal histopathological grades, and serum high-mobility group box 1 concentrations in dogs with inflammatory bowel disease.

BackgroundInflammatory bowel disease (IBD) commonly occurs in dogs, but there is lack of information about potential biomarkers of clinical and histopathologic severity.ObjectiveTo examine the role of serum C‐reactive protein (CRP) and high‐mobility group box 1 (HMGB1) concentrations in dogs with IBD.AnimalsSeventeen dogs with IBD and 25 healthy dogs.MethodsIn this prospective study, duodenal histopathologic severity was graded, and the clinical severity of IBD was assessed by the canine IBD assessment index (CIBDAI) score in dogs with IBD. Serum CRP and HMGB1 concentrations were compared between IBD and healthy dogs and analyzed according to histopathologic grade in dogs with IBD. The correlations between serum CRP and HMGB1 concentrations and the CIBDAI score were evaluated.ResultsDogs with IBD had higher serum CRP (median [range] = 20.39 [1.53‐67.69] μg/mL vs 2.31 [0.17‐11.49] μg/mL; P < .001) and HMGB1 concentrations (0.44 [0.07‐1.58] ng/mL vs 0.05 [0.01‐0.25] ng/mL; P < .001) than healthy dogs. The serum HMGB1 concentration was higher in IBD dogs with a moderate to severe histopathologic grade (0.51 [0.30‐1.58] ng/mL, P = .03) than in those with a mild histopathologic grade (0.17 [0.07‐0.75] ng/mL). Serum CRP concentrations and CIBDAI score were positively correlated in dogs with IBD (r s = .49, P = .05).Conclusions and Clinical ImportanceSerum HMGB1 could be a potential biomarker for diagnosing IBD and might be indicative of histopathologic severity in dogs, whereas serum CRP might be an indicator of clinical severity.

Contrast-enhanced ultrasonography in dogs with inflammatory bowel disease.

BackgroundContrast‐enhanced ultrasonography (CEUS) is used to evaluate vascularity of the gastrointestinal wall in neoplastic and inflammatory diseases.ObjectiveTo assess the feasibility of CEUS for the evaluation of duodenal perfusion in dogs with inflammatory bowel disease (IBD).AnimalsForty‐two dogs with IBD and 20 clinically healthy dogs.MethodsAll CEUS studies of the duodenum were analyzed to obtain time‐intensity curves and perfusion parameters. The procedure was repeated in 12 IBD dogs 2 months after a standardized treatment.ResultsOn CEUS, the duodenal wall showed a typical perfusion pattern characterized by a radial and simultaneous enhancement of the wall in all dogs. On qualitative assessment, no differences were observed in contrast medium distribution between healthy and affected dogs, or between dogs with IBD before and after treatment. Peak intensity (PI) and area under the curve (AUC) significantly differed between healthy (PI = 3.58 arbitrary units [au; 1.86‐4.93 au] and AUC = 47.63 au seconds [aus, 22.68‐62.15]) and affected dogs (PI = 5.10 au [0.63‐15.16 au] and AUC = 63.62 aus [5.31‐212.20 aus]; P = .03 and .03, respectively). No significant differences were found for the perfusion parameters before and after treatment.Conclusions and Clinical ImportanceWe showed that CEUS allows discrimination between IBD affected dogs and healthy dogs by evaluation of time‐intensity curves, but did not provide useful information for monitoring therapeutic response. The qualitative assessment identified no significant differences between healthy and affected dogs, or between dogs before and after treatment.

Clinical Signs, Activity Indices and Prognostic Indicators in Dogs with Idiopathic Inflammatory Bowel Disease

Background: Canine inflammatory bowel disease (IBD) includes a set of diseases characterized by the presence of recurrent gastrointestinal clinical signs and histologic evidence of intestinal inflammation. Diagnosis can only be made by excluding other possible causes of enteritis. Since the diagnosis of this disease is of great challenge to the veterinarians and currently very little work have been carried out in India, the present study was planned and conducted to study the clinicopathological changes and prognostic indicators of idiopathic inflammatory bowel disease (IBD) in dogs.Methods: After a detailed clinical, laboratoty and endoscopic examination, 33 IBD dogs with signs of chronic gastrointestinal disorders and histologic evidence of mucosal lymphocytic plasmacytic infiltration were selected for the study.Result: Moderate to severe form of IBD with haematochezia as a chief complaint was predominantly recorded. Haematobiochemical changes were not remarkable except a rise in serum alkaline phosphatase level. Decreased IgA expression was observed in serum by flowcytometry indicating impaired mucosal immunity in IBD dogs. It was observed that, increased clinical inflammatory bowel disease activity index score (CIBDAI), increased C-Reactive Protein, decreased cobalamin and folate may act as negative predictors in idiopathic IBD.

Abdominal ultrasonography in canine inflammatory bowel disease: A short study

Ultrasonography is a noninvasive and inexpensive tool to examine the gastrointestinal tract of small animals with chronic gastrointestinal signs. It plays a major role in the recognition, diagnosis and monitoring of inflammatory bowel disease (IBD) in human patients. The present study was undertaken to record the ultrasonographic changes associated with canine IBD. Thirty three dogs confirmed with idiopathic IBD were included in the study and subjected to detailed abdominal ultrasonography. This study revealed that dogs with IBD variably have a normal to mildly thickened intestinal wall thickness. Secondary changes recorded in the IBD dogs were gas filled intestinal loops, hypermotility of intestinal loops, dilation of the lumen and mesenteric lymphnode enlargement. In conclusion, intestinal wall measurements do not appear to establish a diagnosis of intestinal inflammation in canine IBD in contrast to humans where ultrasonography has a significant role in establishing the diagnosis.

Treatment With Hydrolyzed Diet Supplemented With Prebiotics and Glycosaminoglycans Alters Lipid Metabolism in Canine Inflammatory Bowel Disease.

Canine inflammatory bowel disease (IBD) is a chronic, immunologically mediated intestinal disorder, resulting from the complex interaction of genetic, environmental and immune factors. Hydrolyzed diets are used in dogs with food-responsive diarrhea (FRD) to reduce adverse responses to immunostimulatory proteins. Prebiotics (PRBs) and glycosaminoglycans (GAGs) have previously been demonstrated to show anti-inflammatory activity in the intestinal mucosa. Notably, hydrolyzed diets combined with the administration of PRBs and GAGs offer a promising approach for the treatment of canine IBD. Our aim was to investigate the effects of hydrolyzed diet and GAG+PRB co-treatment on the serum metabolomic profile of IBD dogs. Dogs with IBD randomly received either hydrolyzed diet supplemented with GAGs and PRBs (treatment 1) or hydrolyzed diet alone (treatment 2) for 10 weeks. A targeted metabolomics approach using mass spectrometry was performed to quantify changes in the serum metabolome before and after treatment and between treatment 1 and 2. Principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), hierarchical cluster analysis (HCA) and univariate statistics were used to identify differences between the treatment groups. PCA, PLS-DA, and HCA showed a clear clustering of IBD dogs before and after hydrolyzed diet, indicating that the treatment impacted the serum metabolome. Univariate analysis revealed that most of the altered metabolites were involved in lipid metabolism. The most impacted lipid classes were components of cell membranes, including glycerophospholipids, sphingolipids, and di- and triglycerides. In addition, changes in serum metabolites after GAG+PRB co-treatment suggested a possible additional beneficial effect on the lipid metabolism in IBD dogs. In conclusion, the present study showed a significant increase in metabolites that protect gut cell membrane integrity in response to hydrolyzed diet alone or in combination with GAG+PRB co-treatment. Administration of such treatment over 70 days improved selected serum biomarkers of canine IBD, possibly indicating improved intestinal membrane integrity.

Evaluation of novel serological markers and autoantibodies in dogs with inflammatory bowel disease.

BackgroundThe use of serological markers to diagnose inflammatory bowel disease (IBD) in humans is well‐established. Because of the frequency of IBD in dogs and resources required for its diagnosis with current methods, new approaches are desired.ObjectiveThe goal is to evaluate novel serologic markers to differentiate clinical cohorts in dogs with gastrointestinal (GI) disease and assess their potential to develop a serum‐based IBD diagnostic test.AnimalsSeventy dogs diagnosed with biopsy‐confirmed IBD, 23 dogs with non‐IBD predominantly acute GI diseases, and 58 normal dogs.MethodsProspective control study. ELISA methods were developed to detect autoantibodies to polymorphonuclear leukocytes (APMNA) and calprotectin (ACNA), antibodies against gliadins (AGA), microbial outer membrane porin C (ACA), and flagellins (AFA) isolated from diseased dogs based on clinical and histopathological scoring.ResultsIBD dogs displayed a 39%‐76% prevalence of seropositivity against selected serologic markers that markedly decreased to 0%‐13% in non‐IBD and normal dogs. ROC analysis showed statistical significance in differentiating the cohorts, with seropositivity against OmpC being the highest single performance marker. The combination of markers such as OmpC and APMNA reached specificities of 93%‐99% and 79%‐98% and sensitivities of 76%‐97% and 66%‐86% when comparing IBD versus normal cohorts and non‐IBD cohorts, respectively.Conclusion and Clinical ImportanceSeropositivity of canine immunoglobulins A against selected serologic markers in dogs appears promising in the detection and differentiation of IBD versus other acute GI conditions. Among them, antibody reactivity to Escherichia coli OmpC and canine autoantibodies against polymorphonuclear leukocytes displayed the highest single marker discriminating performance.

Glucocorticoid and dietary effects on mucosal microbiota in canine inflammatory bowel disease.

The pathogenesis of canine inflammatory bowel disease (IBD) involves complex interactions between mucosal immunity and the intestinal microbiota. Glucocorticoids are commonly administered to reduce mucosal inflammation and gastrointestinal signs. The study objective was to evaluate the effects of diet and oral prednisone on the spatial distribution of mucosal bacteria in IBD dogs. Eight dogs diagnosed with IBD were treated with immunosuppressive doses of prednisone. The mucosal microbiota from endoscopic biopsies of IBD dogs and healthy controls (HC; n = 15 dogs) was evaluated by fluorescence in situ hybridization (FISH) targeting the 16S rRNA genes of total bacteria and bacterial species relevant in canine/human IBD. Apicaljunction protein (AJP) expression using immunohistochemistry investigated the effect of medical therapy on intestinal barrier integrity. All IBD dogs had a reduction in GI signs following diet and prednisone therapy compared with baseline CIBDAI scores (P < 0.05). The mucosal microbiota of HC and diseased dogs was most abundant in free and adherent mucus. Only Lactobacilli were increased (P < 0.05) in the adherent mucus of IBD dogs compared to HC. The spatial distribution of mucosal bacteria was significantly different (P < 0.05) in IBD dogs following prednisone therapy, with higher numbers of Bifidobacteria and Streptococci detected across all mucosal compartments and increased numbers of Bifidobacterium spp., Faecalibacterium spp., and Streptococcus spp. present within adherent mucus. Differences in intestinal AJPs were detected with expression of occludin increased (P < 0.05) in IBD dogs versus HC. The expressions of occludin and E-cadherin were increased but zonulin decreased (P < 0.05 for each) in IBD dogs following prednisone therapy. In conclusion, the spatial distribution of mucosal bacteria differs between IBD and HC dogs, and in response to diet and glucocorticoid administration. Medical therapy was associated with beneficial changes in microbial community structure and enhanced mucosal epithelial AJP expression.

Interleukin‐22, a Pro‐inflammatory Cytokine, is Increased in the Serum of Canines with Inflammatory Bowel Disorder

Inflammatory Bowel Disease (IBD) is characterized by a chronic and/or recurrent inflammatory condition associated with adverse gastrointestinal signs including diarrhea, vomiting, and weight loss. Inflammation plays a key role in the initiation and continual progression of IBD. Interleukin 22 (IL‐22) is a pro‐inflammatory cytokine that is expressed by various cells of the immune system including dendritic cells, natural killer cells, and T cells. IL‐22 is a cytokine that can have either a helpful or a deleterious role in the intestine. The protective role of IL‐22 includes promoting mucosal barrier integrity and epithelial cell regeneration. Its deleterious actions may depend on the presence of other cytokines as well including IL‐23 and IL‐22 binding proteins. Regardless, a continually increased level in IL‐22 can increase associated gastrointestinal inflammatory processes. We tested the circulating levels of IL‐22 in the serum of dogs that were clinically diagnosed as having IBD following an endoscopy conducted by a veterinarian. Blood was collected from dogs with IBD (n=6; 2.2–13.1 yr) and control dogs (n=5; 2.2–11.3 yr) which did not show any signs of IBD. Blood was collected at two different time points (~1 year apart) from the same dogs. Using an ELISA technique, we found that the mean levels of serum IL‐22 from both time points were significantly higher in IBD (286.5 ± 69.32 pg/ml) when compared to controls (104.2 ± 17.8; p&lt;0.05). The levels of IL‐22 in IBD dogs were higher than controls at both individual time points assessed as well. Our results identify IL‐22 as a promising biomarker of inflammatory bowel disorder in dogs and strategies to decrease a continual and elevated level of IL‐22 may be an effective way to reduce the adverse conditions associated with IBD. Further, an optimal anti‐inflammatory nutritional therapy may be a promising option to pursue as a therapeutic measure for IBD in caninesSupport or Funding InformationFunded by Hills PNCThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Sphingosine-1-phosphate (S1P) signaling regulates the production of intestinal IgA and its potential role in the pathogenesis of canine inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a common gastrointestinal disease in dogs. Decreased production of intestinal immunoglobulin A (IgA) has been suggested as a possible pathogenesis in a subset of canine IBD; however, the underlying cause remains unclear. Sphingosine-1-phosphate (S1P) is a lipid mediator that regulates intestinal IgA production by controlling lymphocyte trafficking in mice. The objectives of this study were to clarify the role of S1P in IgA production in dogs and to evaluate the expression of S1P-related molecules in dogs with IBD. First, an S1P receptor antagonist was administrated to five healthy dogs. The S1P receptor antagonist significantly decreased the IgA concentration in sera and feces but did not affect the IgG concentration. Moreover, the immunoreactivity of intestinal IgA was significantly decreased by S1P signal blockade. These results indicate that S1P signaling specifically regulates the intestinal IgA production in dogs. Subsequently, the intestinal S1P concentration and the expression of S1P-related molecules were measured in dogs with IBD and healthy dogs. The intestinal concentration of S1P was significantly lower in dogs with IBD than in healthy dogs. In addition, the gene expression levels of S1P receptor (S1P1) and S1P synthase (SK1) were significantly lower in dogs with IBD than in healthy dogs. Taken together, these observations suggest that decreased S1P production, likely caused by a lower expression of S1P synthetase, leads to attenuation of S1P/S1P1 signaling pathway and the production of intestinal IgA in dogs with IBD.

Assessment of eosinophil peroxidase as a potential diagnostic and prognostic marker in dogs with inflammatory bowel disease

OBJECTIVE To evaluate a method for identifying intact and degranulated eosinophils in the small intestine of dogs with inflammatory bowel disease (IBD) by use of a monoclonal antibody (mAb) against eosinophil peroxidase (EPX). ANIMALS 11 untreated dogs with IBD, 5 dogs with IBD treated with prednisolone, and 8 control dogs with no clinical evidence of gastrointestinal tract disease and no immunosuppressive treatment. PROCEDURES 4-μm-thick sections of paraffin-embedded tissues from necropsy specimens were immunostained with EPX mAb. Stained intact and degranulated eosinophils in consecutive microscopic fields (400X magnification) of the upper (villus tips) and lower (between the muscularis mucosae and crypts) regions of the lamina propria of the jejunum were manually counted. RESULTS Compared with control and treated IBD dogs, untreated IBD dogs had a significantly higher number of degranulated eosinophils in the lower region of the lamina propria. However, no significant differences were detected in the number of intact eosinophils in this region among groups. In the upper region of the lamina propria, untreated IBD dogs had a significantly higher number of degranulated and intact eosinophils, compared with control and treated IBD dogs. Number of degranulated and intact eosinophils did not differ significantly between control and treated IBD dogs. CONCLUSIONS AND CLINICAL RELEVANCE Immunohistologic analysis with EPX mAb yielded prominent granule staining that allowed reliable morphological identification of degranulated and intact eosinophils, which may provide a strategy for quantitative and selective evaluation of eosinophils in gastrointestinal biopsy specimens and a potential method to diagnose IBD and evaluate treatment outcome.

Does canine inflammatory bowel disease influence gut microbial profile and host metabolism?

BackgroundInflammatory bowel disease (IBD) refers to a diverse group of chronic gastrointestinal diseases, and gut microbial dysbiosis has been proposed as a modulating factor in its pathogenesis. Several studies have investigated the gut microbial ecology of dogs with IBD but it is yet unclear if this microbial profile can alter the nutrient metabolism of the host. The aim of the present study was to characterize the faecal bacterial profile and functionality as well as to determine host metabolic changes in IBD dogs.Twenty-three dogs diagnosed with IBD and ten healthy control dogs were included. Dogs with IBD were given a clinical score using the canine chronic enteropathy clinical activity index (CCECAI). Faecal short-chain fatty acids (SCFA) and ammonia concentrations were measured and quantitative PCR was performed. The concentration of plasma amino acids, acylcarnitines, serum folate, cobalamin, and indoxyl sulfate was determined.ResultsNo significant differences in the abundance of a selection of bacterial groups and fermentation metabolites were observed between the IBD and control groups. However, significant negative correlations were found between CCECAI and the faecal proportion of Lactobacillus as well as between CCECAI and total SCFA concentration. Serum folate and plasma citrulline were decreased and plasma valine was increased in IBD compared to control dogs. Increased plasma free carnitine and total acylcarnitines were observed in IBD compared with control dogs, whereas short-chain acylcarnitines (butyrylcarnitine + isobutyrylcarnitine and, methylmalonylcarnitine) to free carnitine ratios decreased. Dogs with IBD had a higher 3-hydroxyisovalerylcarnitine + isovalerylcarnitine to leucine ratio compared to control dogs.ConclusionsCanine IBD induced a wide range of changes in metabolic profile, especially for the plasma concentrations of short-chain acylcarnitines and amino acids, which could have evolved from tissue damage and alteration in host metabolism. In addition, dogs with more severe IBD were characterised by a decrease in faecal proportion of Lactobacillus.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-016-0736-2) contains supplementary material, which is available to authorized users.

Oral chondroitin sulfate and prebiotics for the treatment of canine Inflammatory Bowel Disease: a randomized, controlled clinical trial.

BackgroundCanine inflammatory bowel disease (IBD) is a chronic enteropathy of unknown etiology, although microbiome dysbiosis, genetic susceptibility, and dietary and/or environmental factors are hypothesized to be involved in its pathogenesis. Since some of the current therapies are associated with severe side effects, novel therapeutic modalities are needed. A new oral supplement for long-term management of canine IBD containing chondroitin sulfate (CS) and prebiotics (resistant starch, β-glucans and mannaoligosaccharides) was developed to target intestinal inflammation and oxidative stress, and restore normobiosis, without exhibiting any side effects. This double-blinded, randomized, placebo-controlled trial in dogs with IBD aims to evaluate the effects of 180 days administration of this supplement together with a hydrolyzed diet on clinical signs, intestinal histology, gut microbiota, and serum biomarkers of inflammation and oxidative stress.ResultsTwenty-seven client-owned biopsy-confirmed IBD dogs were included in the study, switched to the same hydrolyzed diet and classified into one of two groups: supplement and placebo. Initially, there were no significant differences between groups (p > 0.05) for any of the studied parameters. Final data analysis (supplement: n = 9; placebo: n = 10) showed a significant decrease in canine IBD activity index (CIBDAI) score in both groups after treatment (p < 0.001). After treatment, a significant decrease (1.53-fold; p < 0.01) in histologic score was seen only in the supplement group. When groups were compared, the supplement group showed significantly higher serum cholesterol (p < 0.05) and paraoxonase-1 (PON1) levels after 60 days of treatment (p < 0.01), and the placebo group showed significantly reduced serum total antioxidant capacity (TAC) levels after 120 days (p < 0.05). No significant differences were found between groups at any time point for CIBDAI, WSAVA histologic score and fecal microbiota evaluated by PCR-restriction fragment length polymorphism (PCR-RFLP). No side effects were reported in any group.ConclusionsThe combined administration of the supplement with hydrolyzed diet over 180 days was safe and induced improvements in selected serum biomarkers, possibly suggesting a reduction in disease activity. This study was likely underpowered, therefore larger studies are warranted in order to demonstrate a supplemental effect to dietary treatment of this supplement on intestinal histology and CIBDAI.

Alterations of the Ileal and Colonic Mucosal Microbiota in Canine Chronic Enteropathies.

BackgroundThe intestinal microbiota is increasingly linked to the pathogenesis of chronic enteropathies (CE) in dogs. While imbalances in duodenal and fecal microbial communities have been associated with mucosal inflammation, relatively little is known about alterations in mucosal bacteria seen with CE involving the ileum and colon.AimTo investigate the composition and spatial organization of mucosal microbiota in dogs with CE and controls.MethodsTissue sections from endoscopic biopsies of the ileum and colon from 19 dogs with inflammatory bowel disease (IBD), 6 dogs with granulomatous colitis (GC), 12 dogs with intestinal neoplasia, and 15 controls were studied by fluorescence in situ hybridization (FISH) on a quantifiable basis.ResultsThe ileal and colonic mucosa of healthy dogs and dogs with CE is predominantly colonized by bacteria localized to free and adherent mucus compartments. CE dogs harbored more (P < 0.05) mucosal bacteria belonging to the Clostridium-coccoides/Eubacterium rectale group, Bacteroides, Enterobacteriaceae, and Escherichia coli versus controls. Within the CE group, IBD dogs had increased (P < 0.05) Enterobacteriaceae and E. coli bacteria attached onto surface epithelia or invading within the intestinal mucosa. Bacterial invasion with E. coli was observed in the ileal and colonic mucosa of dogs with GC (P < 0.05). Dogs with intestinal neoplasia had increased (P < 0.05) adherent (total bacteria, Enterobacteriaceae, E. coli) and invasive (Enterobacteriaceae, E. coli, and Bacteroides) bacteria in biopsy specimens. Increased numbers of total bacteria adherent to the colonic mucosa were associated with clinical disease severity in IBD dogs (P < 0.05).ConclusionPathogenic events in canine CE are associated with different populations of the ileal and colonic mucosal microbiota.

Metabolomic and Clinical Disturbances in Canine Inflammatory Bowel Disease

Canine inflammatory bowel disease (IBD) is a progressive disease with poorly characterized etiology. We sought to gain insight into the metabolic disturbances preceding and co‐incident with canine IBD by comparing the plasma metabolome and clinical indices of dogs (n =30) prior and subsequent to diagnosis of IBD by histopathological assessment of intestinal tissue collected by endoscopy. Archived samples were generated from annual health screens and adventitious health‐related collections curated according to the IBD status of their donors. Metabolomic and clinical analysis was also performed on bioarchived time‐matched samples from disease‐free, healthy control dogs (n = 30). Blood collections were carried out under IACUC approved protocols. Results showed several circulating metabolites of colon microbiota were decreased in IBD dogs, including phenol and indole derivatives. Further disruptions were noted in antioxidant status and lipid metabolism. A stepwise discriminant model selected a subset of clinical markers including liver enzymes, plasma and urine protein, platelets, basophils and monocytes as capable of correctly classifying &gt;90% of samples as derived from post‐IBD versus healthy controls. The clinical findings imply that disruption of the gut and liver barriers, protein‐losing enteropathy and immune perturbation was co‐incident with IBD. In summary, assessment of dogs pre‐, peri‐ and post‐diagnosis implies hindgut dysbiosis, altered redox status and disrupted lipid metabolism accompany clinical disturbances in canine IBD.

Phenotypic characterization of canine intestinal intraepithelial lymphocytes in dogs with inflammatory bowel disease.

BackgroundMany dogs suffering from inflammatory bowel disease (IBD) are presented to veterinary clinics. These patients are diagnosed based on a history of chronic gastrointestinal signs and biopsy‐confirmed histopathologic intestinal inflammation. Intestinal intraepithelial lymphocytes (IEL) are part of the first line of defense in the gastrointestinal immune system. Alterations in IEL subsets may play a role in the pathogenesis of IBD.HypothesisThe aim of this study was to characterize the phenotypes of IEL in dogs with IBD compared with healthy control dogs.AnimalsIntestinal intraepithelial lymphocytes subpopulations of control dogs (n = 5) obtained from endoscopic biopsies (EB) were compared to those obtained from full thickness biopsies (FTB) on the same day. In addition, the phenotypes of IEL from FTB of control dogs (n = 10) were compared with EB of IBD dogs (n = 10). Each participant was scored clinically using the canine inflammatory bowel disease activity index (CIBDAI), and all samples were graded histopathologically. Three‐color flow cytometry of isolated IEL was performed using monoclonal antibodies against T‐ and B‐lymphocyte subpopulations.ResultsNo significant differences in the composition of IEL subpopulations were found in control dogs based on method of biopsy. The IBD dogs had significantly higher CIBDAI and histopathologic scores compared with control dogs and their IEL contained a significantly higher frequency TCRγδ T‐cells.Conclusions and Clinical ImportanceEndoscopic biopsies provide suitable samples for 3‐color flow cytometry when studying canine intestinal IEL and IBD patients show significant changes of major T‐cell subsets compared to healthy control dogs.

Systemic levels of the anti-inflammatory decoy receptor soluble RAGE (receptor for advanced glycation end products) are decreased in dogs with inflammatory bowel disease

Inflammatory bowel disease (IBD) is a common condition in dogs, and a dysregulated innate immunity is believed to play a major role in its pathogenesis. S100A12 is an endogenous damage-associated molecular pattern molecule, which is involved in phagocyte activation and is increased in serum/fecal samples from dogs with IBD. S100A12 binds to the receptor of advanced glycation end products (RAGE), a pattern-recognition receptor, and results of studies in human patients with IBD and other conditions suggest a role of RAGE in chronic inflammation. Soluble RAGE (sRAGE), a decoy receptor for inflammatory proteins (e.g., S100A12) that appears to function as an anti-inflammatory molecule, was shown to be decreased in human IBD patients. This study aimed to evaluate serum sRAGE and serum/fecal S100A12 concentrations in dogs with IBD.Serum and fecal samples were collected from 20 dogs with IBD before and after initiation of medical treatment and from 15 healthy control dogs. Serum sRAGE and serum and fecal S100A12 concentrations were measured by ELISA, and were compared between dogs with IBD and healthy controls, and between dogs with a positive outcome (i.e., clinical remission, n=13) and those that were euthanized (n=6). The relationship of serum sRAGE concentrations with clinical disease activity (using the CIBDAI scoring system), serum and fecal S100A12 concentrations, and histologic disease severity (using a 4-point semi-quantitative grading system) was tested.Serum sRAGE concentrations were significantly lower in dogs with IBD than in healthy controls (p=0.0003), but were not correlated with the severity of histologic lesions (p=0.4241), the CIBDAI score before (p=0.0967) or after treatment (p=0.1067), the serum S100A12 concentration before (p=0.9214) and after treatment (p=0.4411), or with the individual outcome (p=0.4066). Clinical remission and the change in serum sRAGE concentration after treatment were not significantly associated (p=0.5727); however, serum sRAGE concentrations increased only in IBD dogs with complete clinical remission. Also, dogs that were euthanized had significantly higher fecal S100A12 concentrations than dogs that were alive at the end of the study (p=0.0124).This study showed that serum sRAGE concentrations are decreased in dogs diagnosed with IBD compared to healthy dogs, suggesting that sRAGE/RAGE may be involved in the pathogenesis of canine IBD. Lack of correlation between sRAGE and S100A12 concentrations is consistent with sRAGE functioning as a non-specific decoy receptor. Further studies need to evaluate the gastrointestinal mucosal expression of RAGE in healthy and diseased dogs, and also the formation of S100A12-RAGE complexes.

CD4&lt;sup&gt;+&lt;/sup&gt; T Cell Cytokine Gene and Protein Expression in Duodenal Mucosa of Dogs with Inflammatory Bowel Disease

ABSTRACTInflammatory bowel disease (IBD) is a common cause of chronic gastrointestinal signs in dogs. In humans, T helper cells have important roles in the pathogenesis of IBD. In contrast, no specific involvement of a distinct T cell subset has been described in canine IBD. The present study evaluated the gene and protein expression of cytokines of T cell subsets in duodenal mucosa from dogs with IBD. Relative quantification of interleukin (IL)-17A, interferon (IFN)-γ, IL-4 and IL-10 mRNA transcription was performed using duodenal mucosa from 27 IBD dogs and 8 controls. Duodenal mucosal IL-17A, IFN-γ and IL-10 protein levels were determined by ELISA in 15 IBD dogs and 8 controls. There was no significant difference in each cytokines mRNA transcription level between groups. There was no significant difference in IL-17A, IFN-γ and IL-10 protein expression levels between groups. Thus, there is no clear evidence for the involvement of distinct Th cytokine in the pathogenesis of canine IBD.