Canine inflammatory bowel disease: retrospective analysis of diagnosis and outcome in 80 cases (1995-2002)

Quality of life assessment in domestic dogs: An evidence-based rapid review

Assessment of quality of life (QoL) is an important, increasingly popular outcome measure in veterinary research and practice, particularly in dogs. In humans, QoL is commonly assessed by self-reporting and since this is not possible for animals, it is crucial that instruments designed to measure QoL are tested for reliability and validity. Using a systematic, replicable literature search strategy, the aim of this study was to find published, peer-reviewed instruments for QoL assessment in dogs and to assess the quality of these. CAB Abstracts and PubMed were searched in July 2013 using terms relevant to dogs, wellbeing and QoL. Inclusion and exclusion criteria were applied. When instruments were not published in full, authors were contacted to obtain them. Criteria were applied to assess the quality, validity and reliability of the 52 instruments obtained. Twenty-seven additional instruments used in peer-reviewed publications were not included because they had not been fully described in the publication or were not provided by authors upon request. Most of the instruments reviewed (48/52) were disease-specific rather than generic. Only four publications provided a definition of QoL or wellbeing. Only 11/52 instruments demonstrated evidence of assessing reliability or validity, and the quality of these instruments was variable. Many novel, unvalidated instruments have been generated and applied as clinical outcomes before it was known whether they measured QoL. This rapid review can be used to identify currently available and validated canine QoL instruments, and to assess the validity and quality of new or existing instruments.

Endoscopic assessment of the duodenum in dogs with inflammatory bowel disease

BACKGROUND

Endoscopy is performed for direct inspection of the mucosa and acquisition of biopsies in dogs with inflammatory bowel disease (IBD).

AIM

To evaluate the interobserver agreement in the endoscopic assessment of duodenal mucosa in dogs with IBD.

METHODS

Thirty-five archived endoscopic images of grossly normal (n = 6) and inflamed (n = 29) duodenal mucosa were displayed to 3 expert and 5 trainee endoscopists. Each image was assessed independently by endoscopists for mucosal abnormalities using established indices (of hyperemia, granularity, friability, lymphatic dilatation, and erosions) or interpreted as normal mucosa (trial 1). A repeated trial (trial 2) was performed with the same images presented in random order 1 month later, and accompanied by a visual template.

RESULTS

There was slight interobserver agreement in initial mucosal assessment for expert and trainee endoscopists in trial 1 (kappa ≤ 0.02, P > .05). Interobserver agreement improved in trial 2 for both expert and trainee endoscopists (kappa = 0.2, P > .05) for experts and (P < .05) for trainees. There was a significant (P < .01) improvement in trainee endoscopy scores of lesions from trial 1 to trial 2. Regression analysis showed a significant (P < .01) difference between expert versus trainee endoscopy scores in trial 1. Repeat lesion assessment aided by use of a visual template (trial 2) improved the overall scores of trainee endoscopists to near that of expert endoscopists (P = .06).

CONCLUSIONS AND CLINICAL IMPORTANCE

Interobserver agreement of IBD mucosal appearance from endoscopic findings benefitted from operator experience.

Polymorphisms of nucleotide-binding oligomerization domain 2 (NOD2) gene in miniature dachshunds with inflammatory colorectal polyps

Inflammatory colorectal polyps (ICRPs) frequently occur in miniature dachshunds (MDs) in Japan, typically form multiple polyps with severe neutrophil infiltration. ICRPs are speculated as a novel, breed-specific canine inflammatory bowel disease. Pattern recognition receptors (PRRs) play an important role in the differentiation of pathogens from commensal bacteria and food antigens, and polymorphisms of various PRRs have been shown to be associated with human and canine IBD. We recently reported that the reactivity of nucleotide-binding oligomerization domain 2 (NOD2), toll-like receptor (TLR) 1/2, TLR2, and TLR2/6 are greater in ICRP-affected MDs than that in controls. Therefore, this study was aimed to investigate single nucleotide polymorphisms (SNPs) of PRRs associated with ICRPs in MDs. Mutational analysis of canine NOD2, TLR1, TLR2, and TLR6 genes was performed with six ICRP-affected MDs, five control MDs, and five healthy beagles. The mutational analysis identified 13 non-synonymous SNPs in NOD2, TLR1, TLR2, and TLR6 genes, of which six SNPs in NOD2 exon 3 were further analyzed in an association study using 63 ICRP-affected MDs, 82 control MDs, and 237 control dogs of various breeds. Four of the SNPs (A1532G, T1573C, C1688G, and G1880A of the NOD2 gene) were in Hardy-Weinberg equilibrium and in complete linkage disequilibrium in MDs, and their minor allele frequencies were significantly lower in ICRP-affected MDs than in control MDs (0.016 vs. 0.140, P=0.0002). The calculated inheritance model was an additive model (odds ratio=0.10, 95% confidence interval=0.02-0.45, P=0.0001), which indicates that the haplotype with minor alleles in these SNPs (A, T, C, and G in A1532G, T1573C, C1688G, and G1880A) possess a protective effect regarding the development of ICRPs. However, these SNPs were not specific for MDs, although the minor allele frequencies of these SNPs in control MDs were significantly lower than in other breed dogs. These results suggest that the identified four SNPs (A1532G, T1573C, C1688G, and G1880A in the NOD2 gene) may play a role in the pathogenesis of ICRPs in MDs. Because the majority of MDs and other breed dogs do not have the protective alleles, their absence may not be a specific cause of ICRPs in MDs but rather contribute to the development of inflammation.

Stability of 3-bromotyrosine in serum and serum 3-bromotyrosine concentrations in dogs with gastrointestinal diseases

Background

3-Bromotyrosine (3-BrY) is a stable product of eosinophil peroxidase and may serve as a marker of eosinophil activation. A gas chromatography/mass spectrometry method to measure 3-BrY concentrations in serum from dogs has recently been established and analytically validated. The aims of this study were to determine the stability of 3-BrY in serum, to determine the association between peripheral eosinophil counts and the presence of an eosinophilic infiltrate in the gastrointestinal tract, and to compare serum 3-BrY concentrations in healthy dogs (n = 52) and dogs with eosinophilic gastroenteritis (EGE; n = 27), lymphocytic-plasmacytic enteritis (LPE; n = 25), exocrine pancreatic insufficiency (EPI; n = 26), or pancreatitis (n = 27).

Results

Serum 3-BrY concentrations were stable for up to 8, 30, and 180 days at 4°C, −20°C, and −80°C, respectively. There was no significant association between peripheral eosinophil count and the presence of eosinophils in the GI tissues (P = 0.1733). Serum 3-BrY concentrations were significantly higher in dogs with EGE (median [range] = 5.04 [≤0.63-26.26] μmol/L), LPE (median [range] = 3.60 [≤0.63-15.67] μmol/L), and pancreatitis (median [range] = 1.49 [≤0.63-4.46] μmol/L) than in healthy control dogs (median [range] = ≤0.63 [≤0.63-1.79] μmol/L; P < 0.0001), whereas concentrations in dogs with EPI (median [range] = 0.73 [≤0.63-4.59] μmol/L) were not different compared to healthy control dogs.

Conclusions

The present study revealed that 3-BrY concentrations were stable in serum when refrigerated and frozen. No relationship between peripheral eosinophil count and the presence of eosinophils infiltration in the GI tissues was found in this study. In addition, serum 3-BrY concentrations were increased in dogs with EGE, but also in dogs with LPE and pancreatitis. Further studies are needed to determine whether measurement of 3-BrY concentrations in serum may be useful to assess patients with suspected or confirmed EGE or LPE.

Urinary and faecal N-methylhistamine concentrations do not serve as markers for mast cell activation or clinical disease activity in dogs with chronic enteropathies

Background

This study sought to correlate faecal and urinary N-methylhistamine (NMH) concentrations with resting versus degranulated duodenal mast cell numbers in dogs with chronic enteropathies (CE), and investigate correlations between intestinal mast cell activation and clinical severity of disease as assessed by canine chronic enteropathy clinical activity index (CCECAI), and between urinary and faecal NMH concentrations, mast cell numbers, and histopathological scores. Twenty-eight dogs with CE were included. Duodenal biopsies were stained with haematoxylin and eosin (H&E), toluidine blue, and by immunohistochemical labelling for tryptase. Duodenal biopsies were assigned a histopathological severity score, and duodenal mast cell numbers were counted in five high-power fields after metachromatic and immunohistochemical staining. Faecal and urinary NMH concentrations were measured by gas chromatography–mass spectrometry.

Results

There was no correlation between the CCECAI and faecal or urinary NMH concentrations, mast cell numbers, or histopathological score – or between faecal or urinary NMH concentration and mast cell numbers. Post hoc analysis revealed a statistically significant difference in toluidine blue positive mast cells between two treatment groups (exclusion diet with/without metronidazole versus immunosuppression (IS)), with higher numbers among dogs not requiring IS.

Conclusion

Faecal and urinary NMH concentrations and duodenal mast cell numbers were not useful indicators of severity of disease as assessed by the CCECAI or histological evaluation. The number of duodenal mast cells was higher in dogs that did not need IS, i.e. in dogs responding to an exclusion diet (with/without metronidazole), than in dogs requiring IS. Further studies comparing the role of mast cells in dogs with different forms of CE are needed.

Expression of apical junction complex proteins in duodenal mucosa of dogs with inflammatory bowel disease

OBJECTIVE

To determine the expression of tight junction and adherens junction proteins in duodenal mucosa samples of dogs with inflammatory bowel disease (IBD).

ANIMALS

12 dogs with IBD and 6 healthy control Beagles.

PROCEDURES

Duodenal mucosa biopsy samples were endoscopically obtained from dogs with IBD and healthy control Beagles. The expression of claudin-1, -2, -3, -4, -5, -7, and -8; E-cadherin; and β-catenin in the duodenal mucosa samples was determined by means of immunoblotting. The subcellular localization of E-cadherin in the duodenal mucosa samples was determined with immunofluorescence microscopy.

RESULTS

The expression of each claudin and β-catenin was not significantly different between control dogs and dogs with IBD. However, expression of E-cadherin was significantly lower in duodenal mucosa samples of dogs with IBD than it was in samples obtained from healthy control dogs. Results of immunofluorescence microscopy indicated decreased intensity of E-cadherin labeling in the tips of villi in duodenal mucosa samples obtained from 6 dogs with IBD, compared with staining intensity for other dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Results of this study indicated expression of claudin-1, -2, -3, -4, -5, -7, and -8 and β-catenin was not significantly different between duodenal mucosa samples obtained from control dogs and those obtained from dogs with IBD. However, E-cadherin expression was significantly lower in the villus epithelium in duodenal mucosa samples obtained from dogs with IBD versus samples obtained from control dogs, which suggested that decreased expression of that protein has a role in the pathogenesis of IBD in dogs.

Effect of oral administration of metronidazole or prednisolone on fecal microbiota in dogs

Gastrointestinal microbiota have been implicated in the pathogenesis of various gastrointestinal disorders in dogs, including acute diarrhea and chronic enteropathy. Metronidazole and prednisolone are commonly prescribed for the treatment of these diseases; however, their effects on gastrointestinal microbiota have not been investigated. The objective of this study was to evaluate the effects of these drugs on the gastrointestinal microbiota of dogs. Metronidazole was administered twice daily at 12.5 mg/kg to a group of five healthy dogs, and prednisolone at 1.0 mg/kg daily to a second group of five healthy dogs for 14 days. Fecal samples were collected before and after administration (day 0 and 14), and 14 and 28 days after cessation (day 28 and 42). DNA was extracted, and the bacterial diversity and composition of each sample were determined based on 16S ribosomal RNA (rRNA) gene sequences using next-generation sequencing (Illumina MiSeq). In the group administered metronidazole, bacterial diversity indices significantly decreased at day 14, and recovered after the cessation. Principal coordinates analysis and hierarchical dendrogram construction based on unweighted and weighted UniFrac distance matrices revealed that bacterial composition was also significantly altered by metronidazole at day 14 compared with the other time points. The proportions of Bacteroidaceae, Clostridiaceae, Fusobacteriaceae, Lachnospiraceae, Ruminococcaceae, Turicibacteraceae, and Veillonellaceae decreased, while Bifidobacteriaceae, Enterobacteriaceae, Enterococcaceae, and Streptococcaceae increased at day 14 and returned to their initial proportions by day 42. Conversely, no effect of prednisolone was observed on either the bacterial diversity or composition. Reducing pathogenic bacteria such as Fusobacteria and increasing beneficial bacteria such as Bifidobacterium through the administration of metronidazole may be beneficial for promoting gastrointestinal health; however, further investigations into the effects on diseased dogs are needed.

Evaluation of endoscopically obtained duodenal biopsy samples from cats and dogs in an adapter-modified Ussing chamber

This study was conducted to evaluate an adapter-modified Ussing chamber for assessment of transport physiology in endoscopically obtained duodenal biopsies from healthy cats and dogs, as well as dogs with chronic enteropathies. 17 duodenal biopsies from five cats and 51 duodenal biopsies from 13 dogs were obtained. Samples were transferred into an adapter-modified Ussing chamber and sequentially exposed to various absorbagogues and secretagogues. Overall, 78.6% of duodenal samples obtained from cats responded to at least one compound. In duodenal biopsies obtained from dogs, the rate of overall response ranged from 87.5% (healthy individuals; n = 8), to 63.6% (animals exhibiting clinical signs of gastrointestinal disease and histopathological unremarkable duodenum; n = 15), and 32.1% (animals exhibiting clinical signs of gastrointestinal diseases and moderate to severe histopathological lesions; n = 28). Detailed information regarding the magnitude and duration of the response are provided. The adapter-modified Ussing chamber enables investigation of the absorptive and secretory capacity of endoscopically obtained duodenal biopsies from cats and dogs and has the potential to become a valuable research tool. The response of samples was correlated with histopathological findings.

Efficacy of AST-120 in dogs with chronic idiopathic enteropathies

BACKGROUND

Chronic idiopathic enteropathies (CIE) in dogs are complex diseases of unknown origin. AST-120 is a spherical carbon adsorbent preparation with a high adsorption ability for low molecular substances.

OBJECTIVES

Evaluation of the clinical efficacy of AST-120 in dogs with CIE.

ANIMALS

Ten client-owned dogs with mild (n = 7) to moderate (n = 3) CIE.

METHODS

Explorative, prospective, randomized, placebo-controlled, double-blinded pilot study. Dogs with chronic diarrhea and no or insufficient response to an elimination diet were included. The dogs received either AST-120 (n = 5) or placebo (n = 5) for a duration of 21 days. The canine inflammatory bowel disease activity index (CIBDAI) was used to assess disease severity at baseline and clinical outcome after 3 weeks of treatment. Furthermore, changes in body weight and the parameters stool consistency and frequency were compared within and between groups.

RESULTS

The mean CIBDAI score decreased from 5.6 (SD 1.5) to 2.0 (SD 1.2) in the AST-120 group (P = .125) and from 4.8 (SD .8) to 3.6 (SD 2.3) in the placebo group (P = .688). Compared with baseline, posttreatment CIBDAI scores decreased more than 60% in 4/5 dogs treated with AST-120 and in 1/5 dogs treated with placebo (P = .206). Changes in CIBDAI scores, body weights, stool consistency, and frequency within and between groups did not achieve statistical significance after 3 weeks of treatment. No adverse effects of AST-120 were noted.

CONCLUSIONS AND CLINICAL IMPORTANCE

This study investigated potential efficacy of AST-120 as an alternative therapy in dogs with mild-to-moderate CIE.

Diagnosis of small intestinal disorders in dogs and cats

Laboratory tests are an important part of the workup of small intestinal diseases in dogs and cats. Especially in chronic cases, when extragastrointestinal causes need to be ruled out, it is important to adhere to a systematic workup. This article details the newest available data on tests to aid this diagnostic process. Once the diagnosis of a chronic enteropathy is made, there are many laboratory tests that can help in monitoring the disease and providing prognostic information. Several new tests being evaluated for clinical usefulness are discussed.

Canine gut dendritic cells in the steady state and in inflammatory bowel disease

Alongside the intestinal border, dendritic cells (DCs) sample large amounts of endogenous and potentially pathogenic antigens followed by initiation of protective immune responses or induction of tolerance. Breakdown of oral tolerance towards commensal bacteria is suggested to be crucial for the development of both human and canine inflammatory bowel disease (IBD). The aim of this study was to investigate canine intestinal DCs in the steady state and in dogs with IBD using multicolour immunofluorescence. In the healthy gut, DC-like cells expressed MHC II, CD1a8.2 and CD11c, and, in lower amounts, CD11b, within lamina propria, Peyer's patches (PPs) and mesenteric lymph nodes (MLNs), whereas those expressing CD80 and CD86 were only present in PPs and MLNs. Occasionally, DC-like cells were in contact with the intestinal lumen through transepithelial projections. In canine IBD, CD1a8.2+, CD11b+ and CD11c+ DC-like cells were decreased within the stomach, duodenum and colon, whereas the colonic mucosa revealed elevation of CD86+ DC-like cells. The complex network of DC-like cells in the gut indicates their important role in canine mucosal immunity, including active sampling of luminal antigens. Furthermore, their shift in diseased dogs suggests a pathogenetic significance for canine IBD.

The characteristics of short- and long-term surviving Shiba dogs with chronic enteropathies and the risk factors for poor outcome

Background

The objectives of this study were to investigate the differences in the characteristics of short- and long-term surviving dogs, and the factors that predict poor outcome in Shiba dogs with chronic enteropathies (CE).

Methods

A total of 25 Shiba dogs were included in this study, and classified as either short-term (≤6 months) survivors (Ss; n=16) or long-term (>6 months) survivors (Ls; n=9). The clinical and clinicopathological variables, histopathology, response to therapy, and outcomes were investigated between groups. Furthermore, these factors were tested for their ability to predict poor outcome.

Results

All CE dogs were diagnosed as having inflammatory bowel disease (IBD) with lymphocytic-plasmacytic enteritis (LPE). Age and canine inflammatory bowel disease activity index (CIBDAI) were significantly higher in the Ss group than in the Ls group (age: p = 0.035, CIBDAI: p = 0.018), as determined via univariate logistic regression analysis. According to receiver operator characteristic (ROC) curve analysis, the best predictors of poor outcome were age and CIBDAI, with the cutoffs determined as 7 years and 9 points, respectively. The majority of the cases (84%) responded to initial treatment; in particular, 75% of dogs in Ss group responded to therapy. The time to response (days) to the initial treatment in the Ss group (median 42.5 days, range: 20-91 days) was significantly shorter than that of the Ls group (median 285 days, range: 196-1026 days). Approximately half (55.5%) of the dogs in the Ls group died due to relapse of CE.

Conclusions

This study suggested that there is a high risk of early mortality in Shiba dogs with CE, particularly if the dogs are older (>7 years) and have a high CIBDAI score (>9 points). There appears to be a possibility of early mortality even if the initial treatment was efficacious. Furthermore, Shiba dogs with CE that become less responsive to initial therapy in the short-term (approximately 3 months) are more likely to have an early mortality. Thus, it is necessary to follow-up Shiba dogs with CE in the long-term, as approximately half of the long-term survivors eventually died due to a relapse of the signs.

Cobalamin in companion animals: diagnostic marker, deficiency states and therapeutic implications

Measurement of the water-soluble vitamin cobalamin has long been of interest as a marker of gastrointestinal disease in companion animals due to the highly localized presence of cobalamin receptors in the ileum. An increasing body of evidence suggests that cobalamin deficiency is an important co-morbidity in many companion animal patients with gastrointestinal and pancreatic disease. Congenital disorders of cobalamin absorption and cellular metabolism are also increasingly recognized in companion animal breeds. The early recognition of these disorders and timely treatment with parenteral cobalamin can be life-saving. In this article, the normal mechanisms of cobalamin absorption, the use of cobalamin as a marker of intestinal disease and data on the prevalence of hypocobalaminemia in a variety of diseases are described. The prognostic impact of and rational therapy for hypocobalaminemia in domestic animals are discussed.

Diagnostic utility of abdominal ultrasonography in dogs with chronic diarrhea

BACKGROUND

Chronic diarrhea is common in dogs and has many causes. Ultrasonographic descriptions of many gastrointestinal diseases have been published, but the diagnostic utility of ultrasonography in dogs with chronic diarrhea has not been investigated.

HYPOTHESIS

Diagnostic utility of abdominal ultrasound will be highest in dogs with GI neoplasia and lowest in those with inflammatory disorders.

ANIMALS

87 pet dogs with chronic diarrhea.

METHODS

Prospective study in which medical records were reviewed and contribution of abdominal ultrasound toward making diagnosis was scored.

RESULTS

In 57/87 (66%) of dogs, the same diagnosis would have been reached without ultrasonography. In 13/87 (15%) of dogs, the ultrasound examination was vital or beneficial to making the diagnosis. Univariable analysis identified that increased diagnostic utility was associated with weight loss (P = .0086), palpation of an abdominal or rectal mass (P = .0031), diseases that commonly have mass lesions visible on ultrasound examination (P < .0001), and a final diagnosis of GI neoplasia. Multivariable regression indicated that utility of abdominal ultrasonography would be 30 times more likely to be high in dogs in which an abdominal or rectal mass was palpated (odds ratio 30.5, 95% CI 5.5-169.6) (P < .0001) versus dogs without a palpable mass. In 15/87 (17%) of dogs, additional benefits of ultrasonography to case management, independent of the contribution to the diagnosis of diarrhea, were identified.

CONCLUSIONS AND CLINICAL IMPORTANCE

Overall, the diagnostic utility of abdominal ultrasonography was low in dogs with chronic diarrhea. Identification of factors associated with high diagnostic utility is an indication to perform abdominal ultrasonography in dogs with chronic diarrhea.

Influence of P-glycoprotein modulation on plasma concentrations and pharmacokinetics of orally administered prednisolone in dogs

OBJECTIVE

To evaluate the impact of modulation of the membrane-bound efflux pump P-glycoprotein (P-gp) on plasma concentrations of orally administered prednisolone in dogs.

ANIMALS

7 healthy adult Beagles.

PROCEDURES

Each dog received 3 treatments (control [no treatment], rifampicin [100 mg/d, PO, for 21 days, as an inducer of P-gp], and ketoconazole [100 mg/d, PO, for 21 days, as an inhibitor of P-gp]). A single dose of prednisolone (1 mg/kg, PO) was administered on day 8 of each treatment period. There was a 7-day washout period between subsequent treatments. Plasma concentrations of prednisolone were determined by use of a validated liquid chromatography-tandem mass spectrometry method. Duodenum and colon biopsy specimens were obtained endoscopically from anesthetized dogs and assessed for P-gp protein labeling via immunohistochemical analysis and mRNA quantification via real-time PCR assay. Total fecal collection was performed for evaluation of effects of P-gp modulation on digestion of nutrients.

RESULTS

Rifampicin treatment upregulated duodenal P-gp in dogs and significantly reduced the area under the plasma concentration-time curve of prednisolone. Ketoconazole typically downregulated expression of duodenal P-gp, with a subsequent increase in the area under the plasma concentration-time curve of prednisolone. There was a noticeable interindividual difference in response. Digestion of nutrients was not affected.

CONCLUSIONS AND CLINICAL RELEVANCE

Modulation of P-gp expression influenced plasma concentrations of prednisolone after oral administration in dogs. Thus, treatment response to prednisolone may be influenced by coadministration of P-gp-modulating medications or feed ingredients.

Adapter-modified Ussing chamber enables evaluation of endoscopically-obtained colonic biopsy samples from cats and dogs

Adapter-modified Ussing chambers have been used for assessment of endoscopically obtained intestinal biopsies in humans. The aim of this study was to evaluate the feasibility of an adapter-modified Ussing chamber for assessment of intestinal transport physiology in endoscopically-obtained colonic biopsies from cats and dogs. Fifteen colonic biopsies from four cats and 13 colonic biopsies from four dogs were transferred into a modified Ussing chamber and sequentially exposed to several compounds. Baseline mean±SD conductance was measured. Changes of short circuit current (ΔIsc) were observed after exposure to glucose (number of feline biopsies that responded=0/number of canine biopsies that responded=4), phloridzin (n=0/n=7), histamine (n=5/n=12), serotonin (n=7/n=12), prostaglandin (n=5/n=7), forskolin (n=7/n=7), and ouabain (n=9/n=7). The adapter-modified Ussing chamber studied here enables investigation of transport physiology of endoscopically-obtained colonic biopsies from companion animals. However, we observed a large variability of results, suggesting that clinical use of this method is limited.

16S rRNA gene pyrosequencing reveals bacterial dysbiosis in the duodenum of dogs with idiopathic inflammatory bowel disease

Background

Canine idiopathic inflammatory bowel disease (IBD) is believed to be caused by a complex interaction of genetic, immunologic, and microbial factors. While mucosa-associated bacteria have been implicated in the pathogenesis of canine IBD, detailed studies investigating the enteric microbiota using deep sequencing techniques are lacking. The objective of this study was to evaluate mucosa-adherent microbiota in the duodenum of dogs with spontaneous idiopathic IBD using 16 S rRNA gene pyrosequencing.

Methodology/Principal Findings

Biopsy samples of small intestinal mucosa were collected endoscopically from healthy dogs (n = 6) and dogs with moderate IBD (n = 7) or severe IBD (n = 7) as assessed by a clinical disease activity index. Total RNA was extracted from biopsy specimens and 454-pyrosequencing of the 16 S rRNA gene was performed on aliquots of cDNA from each dog. Intestinal inflammation was associated with significant differences in the composition of the intestinal microbiota when compared to healthy dogs. PCoA plots based on the unweighted UniFrac distance metric indicated clustering of samples between healthy dogs and dogs with IBD (ANOSIM, p<0.001). Proportions of Fusobacteria (p = 0.010), Bacteroidaceae (p = 0.015), Prevotellaceae (p = 0.022), and Clostridiales (p = 0.019) were significantly more abundant in healthy dogs. In contrast, specific bacterial genera within Proteobacteria, including Diaphorobacter (p = 0.044) and Acinetobacter (p = 0.040), were either more abundant or more frequently identified in IBD dogs.

Conclusions/Significance

In conclusion, dogs with spontaneous IBD exhibit alterations in microbial groups, which bear resemblance to dysbiosis reported in humans with chronic intestinal inflammation. These bacterial groups may serve as useful targets for monitoring intestinal inflammation.

Immunohistochemical investigation of Foxp3 expression in the intestine in healthy and diseased dogs

Intestinal immune regulation including development of oral tolerance is of great importance for the maintenance of intestinal homeostasis. Concerning this, regulatory T cells (Tregs) occupy a pivotal role in cell-mediated immunosuppression. Dysregulation of mucosal immunology leading to an abnormal interaction with commensal bacteria is suggested to play a key role in the pathogenesis of Inflammatory Bowel Disease (IBD) in men and dogs. The aim of this study was to characterise the expression of Foxp3 in the normal canine gut of 18 dogs (mean age: 6.03 years), in 16 dogs suffering from IBD (mean age: 5.05 years), and of 6 dogs with intestinal nematode infection (mean age: 0.87 years) using immunohistochemistry. In the duodenum, Tregs in healthy dogs declined from villi (median: 10.67/62 500 μm2) to crypts (median: 1.89/62 500 μm2). Tregs were further increased in the villi of middle-aged dogs (median: 18.92/62 500 μm2) in contrast to juvenile (median: 3.50/62 500 μm2) and old (median: 9.56/62 500 μm2) individuals. Compared to healthy controls, animals suffering from IBD revealed reduced numbers of Tregs in duodenal villi (median: 4.13/62 500 μm2). Dogs with intestinal nematode infection displayed increased numbers of Tregs (median: 21.06/62 500 μm2) compared to healthy animals.Age-related changes indicate a progressive establishment of oral tolerance and immunosenescence in the canine elderly. The results further suggest that a defect in Treg homeostasis may be involved in the pathogenesis of canine IBD. In contrast, increased numbers of Tregs in the duodenum may be due to nematode infection.

Canine breeds at high risk of developing inflammatory bowel disease in the south-eastern UK

Genetics are an important factor in the development of human inflammatory bowel disease (IBD); however, there is very little information available regarding the role of genetics in canine IBD. The purpose of this study was to gather information about which canine breeds in the south-eastern UK are at a high risk for developing IBD. Determination of such breeds may help further genetic research in this complex disease. The computer medical records at the Queen Mother Hospital for Animals, Royal Veterinary College dating from August 1, 2003 to December 31, 2009 were retrospectively searched for cases diagnosed with IBD. Five hundred and forty-six dogs with IBD were identified, representing 86 different breeds. The comparison group consisted of all dogs from these same 86 breeds without IBD admitted to the hospital during the same period that amounted to 27,463 dogs. The breeds at significantly higher risk of developing IBD compared with mixed-breed dogs consisted of weimaraner (odds ratio [OR]=3.6797, 95 per cent confidence interval [CI]=2.0167 to 6.7141, P<0.0001), rottweiler (OR=2.9697, 95 per cent CI=1.7569 to 5.0196, P<0.0001), German shepherd dog (GSD) (OR=2.4101, 95 per cent CI=1.5826 to 3.36705, P<0.0001), border collie (OR=1.9936, 95 per cent CI=1.1655 to 3.4101, P=0.0118) and boxer (OR=1.6961, 95 per cent CI=1.0441 to 2.755, P=0.0328). This study demonstrates for the first time canine breeds in the south-eastern UK that are highly susceptible to developing IBD. Identification of such breeds may allow for a more focused investigation of genetic mutations associated with canine IBD.

Assessment of quality of life in equine patients

REASONS FOR PERFORMING STUDY

Assessing patients' quality of life (QOL) is a core part of clinical decision making. Various methodologies for assessing patients' QOL have been developed in human medicine and small animal veterinary disciplines. In contrast, the lack of aids for QOL assessment in equine veterinary practice leaves practitioners reliant on subjective assessments of QOL, which may be prone to avoidable errors.

OBJECTIVES

This paper suggests pragmatic ways in which QOL may be enhanced, while remaining appropriate for the time, financial and owner-based constraints within equine practice.

METHODS

Through interdisciplinary research, this paper identifies, adapts and applies insights from several areas of research and practical experience in order to develop an overarching approach to making QOL-based decisions in clinical cases.

RESULTS

The paper identifies 6 steps involved in QOL-based decision making and provides examples of how these steps may be practically applied. These include deciding what each clinician feels is important; deciding how to evaluate it, including taking owners' views into consideration; making decisions about each case and achieving the desired clinical outcomes.

CONCLUSIONS

Practitioners can draw their own conclusions on how they may improve QOL assessment in practice and may usefully share these with colleagues. Reporting cases and sharing practical examples of QOL tools used on the ground are vital to the development of this field and appropriate methodologies.

POTENTIAL RELEVANCE

Improvements in QOL assessment are relevant to all areas of equine veterinary practice, and several areas of research. Further research may develop QOL assessment in practice, but more important are the personal improvements that each practitioner may achieve.

Pitfalls and progress in the diagnosis and management of canine inflammatory bowel disease

Inflammatory bowel disease (IBD) is the collective term for a group of chronic enteropathies characterized by persistent or recurrent gastrointestinal (GI) signs and inflammation of the GI tract. The specific steps that lead to IBD and the basis for phenotypic variation and unpredictable responses to treatment are not known. This article examines IBD in dogs, focusing on the interaction between genetic susceptibility and the enteric microenvironment (bacteria, diet), the utility of recently developed histologic criteria, the prognostic indicators, and the standardized approaches to treatment.

White spots on the mucosal surface of the duodenum in dogs with lymphocytic plasmacytic enteritis

Distended lacteals, described as expanded white villi in duodenum, are strongly indicative of primary intestinal lymphangiectasia. In the present study, we evaluated the significance of white spots present in the duodenal mucosa of dogs with lymphocytic plasmacytic enteritis (LPE). Fifty dogs with LPE were included in this study, and white spots were detected in the duodenal mucosa in 22 dogs during endoscopy. Hypoproteinemia was more frequent in dogs with white spots than in dogs without spots (p = 0.02). Serum protein and albumin concentration were significantly lower in LPE dogs with white spots (p = 0.038) compared to LPE dogs without white spots (p = 0.039). There was a significant correlation between white spots density and lymphatic dilatation histological scores (p = 0.023; ρ = 0.481). These results suggest that the presence of white spots in the duodenal mucosa of dogs is not a finding exclusive for intestinal lymphangiectasia. Low serum protein and albumin concentrations together with lymphatic dilatation seem to be related to the presence of white spots in the duodenal mucosa of LPE dogs.

CD11c+ cells are significantly decreased in the duodenum, ileum and colon of dogs with inflammatory bowel disease

CD11c serves as a marker for human and murine dendritic cells (DCs) and cells expressing this marker have been shown to have similar morphological and functional characteristics in the canine immune system. The aim of this study was to quantify CD11c(+) cells in the duodenum, ileum and colon of healthy dogs and dogs with inflammatory bowel disease (IBD). Endoscopic biopsies from the duodenum (n=12 cases), ileum (n=8 cases) and colon (n=12 cases) were obtained from dogs diagnosed with IBD. Intestinal tissue from 10 healthy beagle dogs was used as control. Immunofluorescence microscopy was carried out using an anti-canine CD11c monoclonal antibody. Labelled cells were recorded as cells per 120,000 μm(2). The canine chronic enteropathy clinical activity index (CCECAI) was calculated for all dogs with IBD. In addition, sections from all dogs with IBD were evaluated according to the guidelines of the World Small Animal Veterinary Association Gastrointestinal Standardization Group. The number of CD11c(+) cells in the duodenum, ileum and colon of dogs with IBD was significantly reduced compared with controls (P<0.01, P<0.01 and P<0.05, respectively). There was a significant negative correlation between the number of CD11c(+) cells in the colon of dogs with IBD and the CCECAI (P=0.044, r(2)=-0.558). Chronic inflammation in canine IBD appears to involve an imbalance in the intestinal DC population. Future studies will determine whether reduced expression of CD11c could be a useful marker for the diagnosis and monitoring of canine IBD.

Laboratory tests for diagnosis of gastrointestinal and pancreatic diseases

The panel of laboratory tests available for diagnosis of gastrointestinal (GI) diseases in dogs and cats is wide, and, recently, several new tests have been developed. This article will focus on advances in laboratory tests that are available for the general practitioner for diagnosis of GI diseases. Laboratory tests for diagnosis of gastric and intestinal infectious diseases include fecal parasite screening tests, enzyme-linked immunosorbent assays for parvoviral enteritis, and some specific bacterial tests like fluorescent in situ hybridization for identification of specific bacteria attached to the intestinal epithelial cells. Serum concentrations of folate and cobalamin are markers of intestinal absorption, but are also changed in exocrine pancreatic insufficiency and intestinal bacterial overgrowth. Hypocobalaminemia is common in GI and pancreatic disease. Decreased serum trypsin-like immunoreactivity is a very sensitive and specific test for the diagnosis of exocrine pancreatic insufficiency in dogs and cats. Serum pancreatic lipase is currently the most sensitive and specific test to identify pancreatic cell damage and acute pancreatitis. However, serum canine pancreas-specific lipase is less sensitive in canine chronic pancreatitis. Increased serum trypsin-like immunoreactivity is also specific for pancreatic damage but is less sensitive. It is very likely that further studies will help to better specify the role of these new tests in the diagnosis of canine and feline pancreatic diseases.

Evaluation of erythrocytes, platelets, and serum iron profile in dogs with chronic enteropathy

The aim of this study is to evaluate iron status, erythrocyte, and platelet modifications in dogs with chronic enteropathy (CE). Dogs were grouped as food-responsive diarrhea (FRD, n = 11), antibiotic-responsive diarrhea (ARD, n = 5), and steroid-responsive diarrhea (SRD, n = 6) relating to therapeutic-response. Clinical and haematological findings, evidence of gastrointestinal blood loss, and iron metabolism were evaluated before and after treatment. A mild normocytic or microcytic anemia and thrombocytosis were identified, respectively in 18.0% and 31.8% of CE dogs. No significant differences between pre- and posttreatment of hematocrit, haemoglobin, and mean corpuscular volume, platelet count and mean platelet volume were found. Statistical analysis pointed out significant differences between pre- and posttreatment in serum iron (P < .03) and unsaturated iron binding capacity (UIBC) (P < .01). No significant correlations were found between these parameters and canine Inflammatory Bowel Disease activity index and pattern of CE as well.

Comparison of oral prednisone and prednisone combined with metronidazole for induction therapy of canine inflammatory bowel disease: a randomized-controlled trial

BACKGROUND

Although prednisone and metronidazole are commonly used to treat canine inflammatory bowel disease (IBD), no randomized-controlled trials have been performed.

HYPOTHESIS

Combination drug therapy with prednisone and metronidazole will be more effective than prednisone alone for treatment of canine IBD. Reduction in disease severity will be accompanied by decreased canine IBD activity index (CIBDAI) scores and serum C-reactive protein (CRP) concentrations.

ANIMALS

Fifty-four pet dogs diagnosed with IBD of varying severity.

METHODS

Dogs were randomized to receive oral prednisone (1 mg/kg; n = 25) or prednisone and metronidazole (10 mg/kg; n = 29) twice daily for 21 days. Clinical (CIBDAI) scores and serum CRP were determined at diagnosis and after 21 days of drug therapy. The primary efficacy measure was remission at 21 days, defined as a 75% or greater reduction in baseline CIBDAI score.

RESULTS

Differences between treatments in the rate of remission (both exceeding 80%) or the magnitude of its change over time were not observed. CRP concentrations in prednisone-treated dogs were increased because of many dogs having active disease. Both treatments reduced CRP in comparison with pretreatment concentrations. An interaction between CIBDAI and CRP was identified in 42 of 54 dogs (78%), whereas 8 of 54 dogs (15%) showed disagreement between these indices.

CONCLUSIONS AND CLINICAL IMPORTANCE

Prednisone is as effective as combined treatment with prednisone and metronidazole for induction therapy of canine IBD. CRP may be normal or increased in dogs with IBD and may be useful in assessing the response of individual dogs to treatment along with changes in the CIBDAI.

Evaluation of mucosal bacteria and histopathology, clinical disease activity and expression of Toll-like receptors in German shepherd dogs with chronic enteropathies

The pathogenesis of chronic enteropathies in dogs likely involves an interaction between the intestinal immune system and luminal intestinal bacteria. German shepherd dogs (GSD) are particularly predisposed to chronic enteropathies. The present study sought to evaluate expression patterns of certain pattern recognition receptors of the innate immunity (Toll-like receptors, TLR), clinical disease activity and histopathological severity in GSD with chronic enteropathies. Mucosal biopsies were collected from the duodenum, colon and ileum of 13 affected GSD and 10 healthy greyhounds as controls. Dogs were objectively assessed using published scoring systems for clinical and histological severity of disease. Diversity of the duodenal microbiota was assessed by construction of 16S rRNA gene libraries. Expression of TLR2, TLR4, TLR5 and TLR9 in biopsies of the duodenum, ileum and colon was assessed by quantitative real-time PCR. TLR4 expression was increased in all intestinal segments in GSD, however, TLR5 expression was very low compared to the healthy dogs. The microbiota in the duodenum of GSDs was significantly different to that of the greyhounds, with an over-representation of 16S rRNA gene sequences belonging to the classes of Bacilli, and Erysipelotrichi, and to the orders of Lactobacillales, Actinomycetales and Erysipelotrichales. These findings could point to a distinct pathogenesis of chronic enteropathies in GSD, with differentially high and low expression of TLR4 and TLR5, respectively, and increased proportions of specific members of the Lactobacillales potentially playing a role.

Inflammatory bowel disease in the dog: Differences and similarities with humans

Inflammatory bowel diseases (IBD) represent important chronic conditions affecting the gastrointestinal tract in man. However, similar disorders are found in several animal species and the IBD affecting dogs are particularly important. These are encompassed by an umbrella of probably several different entities with common symptoms, some of which seem to share striking similarities with human conditions. This review will focus on the actual knowledge of IBD in dogs, and attempt to identify differences and similarities with human IBD conditions.

Expression of Toll-like receptor 2 in duodenal biopsies from dogs with inflammatory bowel disease is associated with severity of disease

There is growing evidence that aberrant innate immune responses towards the bacterial flora of the gut play a role in the pathogenesis of canine inflammatory bowel disease (IBD). Toll-like receptors (TLR) play an important role as primary sensors of invading pathogens and have gained significant attention in human IBD as differential expression and polymorphisms of certain TLR have been shown to occur in ulcerative colitis (UC) and Crohn's disease (CD). The aim of the current study was to evaluate the expression of two TLR important for recognition of commensals in the gut. TLR2 and TLR4 mRNA expression in duodenal biopsies from dogs with IBD was measured and correlated with clinical and histological disease severity. Endoscopic duodenal biopsies from 20 clinical cases and 7 healthy control dogs were used to extract mRNA. TLR2 and TLR4 mRNA expression was assessed using quantitative real-time PCR. TLR2 mRNA expression was significantly increased in the IBD dogs compared to controls, whereas TLR4 mRNA expression was similar in IBD and control cases. In addition, TLR2 mRNA expression was mildly correlated with clinical severity of disease, however, there was no correlation between TLR2 expression and histological severity of disease.