Background Mounting evidence from human studies suggests that bile acid dysmetabolism might play a role in various human chronic gastrointestinal diseases. It is unknown whether fecal bile acid dysmetabolism occurs in dogs with chronic inflammatory enteropathy (CE). Objective To assess microbial dysbiosis, fecal unconjugated bile acids (fUBA), and disease activity in dogs with steroid‐responsive CE. Animals Twenty‐four healthy control dogs and 23 dogs with steroid‐responsive CE. Methods In this retrospective study, fUBA were measured and analyzed. Fecal microbiota were assessed using a dysbiosis index. The canine inflammatory bowel disease activity index was used to evaluate remission of clinical signs. This was a multi‐institutional study where dogs with steroid‐responsive CE were evaluated over time. Results The dysbiosis index was increased in dogs with CE (median, 2.5; range, −6.2 to 6.5) at baseline compared with healthy dogs (median, −4.5; range, −6.5 to −2.6; P = .002) but did not change in dogs with CE over time. Secondary fUBA were decreased in dogs with CE (median, 29%; range, 1%‐99%) compared with healthy dogs (median, 88%; 4%‐96%; P = .049). The percent of secondary fUBA in dogs with CE increased from baseline values (median, 28%; range, 1%‐99%) after 2‐3 months of treatment (median, 94%; range, 1%‐99%; P = 0.0183). Conclusions and Clinical Importance These findings suggest that corticosteroids regulate fecal bile acids in dogs with CE. Additionally, resolution of clinical activity index in dogs with therapeutically managed CE and bile acid dysmetabolism are likely correlated. However, subclinical disease (i.e., microbial dysbiosis) can persist in dogs with steroid‐responsive CE.

Background: Tylosin is commonly prescribed to dogs with diarrhea. Orally administered antibiotics may alter the intestinal microbiota, which is responsible for crucial key bile acid (BA) biotransformation reactions.Objectives: To prospectively evaluate the impact of tylosin administration on fecal microbiota and unconjugated bile acids (UBAs) over time.Animals: Sixteen healthy adult dogs.Methods: Prospective, randomized controlled clinical trial. Dogs were randomized to receive 20 mg/kg of tylosin or a placebo capsule PO q12h for 7 days while undergoing daily fecal scoring. Fecal samples were collected on days 0, 7, 21, and 63. The microbiota was assessed using quantitative PCR and 16S rRNA gene sequencing. Unconjugated BAs were assessed using gas chromatography-mass spectrometry (GC-MS).Results: Fecal scores were unchanged during placebo and tylosin administration.In the placebo group, no significant changes were observed in fecal microbiota or UBA concentrations. Day 7 samples from tylosin-exposed dogs exhibited decreased bacterial diversity (observed species, Chao1, Shannon, P < .001) characterized by decreases in anaerobes Fusobacteriaceae (linear discriminant analysis [LDA] score, 5.03) and Veillonellaceae (LDA score, 4.85). Primary UBA concentrations were increased at day 21 (median, [range]; 7.42, [0.67-18.77] μg/kg; P = .04) and day 63 (3.49 [0-28.43] μg/kg; P = .02) compared to day 0 (.14 [.03-1.19] μg/kg) in dogs receiving tylosin. At day 63, bacterial taxa were not significantly different compared to day 0, but the extent of microbial recovery was individualized.Conclusions and Clinical Importance: Tylosin causes fecal dysbiosis in healthy dogs with corresponding shifts in fecal UBAs. Changes did not uniformly resolve after discontinuation of tylosin.

The intestinal microbiota is increasingly linked to the pathogenesis of idiopathic inflammatory bowel disease (IBD) in dogs. While studies have reported alterations in fecal (luminal) microbial populations, only limited information is available about the mucosal microbiota of IBD dogs at diagnosis and following medical therapy. Our aim was to characterize the mucosal microbiota and determine the clinical, microbiological, and mucosal homeostatic effects of probiotic treatment in dogs with IBD. Thirty four IBD dogs were randomized to receive standard therapy (ST = diet + prednisone) with or without probiotic. Tissue sections from endoscopic biopsies were evaluated by fluorescence in situ hybridization (FISH) on a quantifiable basis. Disease activity and changes in mucosal microbiota and tight junction protein (TJP) expression were assessed before and after 8 weeks of IBD therapy. ST and ST/probiotic therapy modulated the number of mucosal bacteria of IBD dogs in a similar fashion. Both treatments increased the numbers of total bacteria and individual species residing within adherent mucus, with ST therapy increasing Bifidobacterium spp. and ST/probiotic therapy increasing Lactobacillus spp (P < 0.05 for both), respectively. Both treatments were associated with rapid clinical remission but not improvement in histopathologic inflammation. Probiotic therapy was associated with upregulated (P < 0.05) expression of TJPs E-cadherin, occludin, and zonulin versus ST. The probiotic effect on mucosal bacteria is similar to that of IBD dogs receiving ST. IBD dogs fed probiotic had increased TJP expression suggesting that probiotic may have beneficial effects on mucosal homeostasis.

Background: Oxidative stress is an important component in the progression of chronic renal failure (CRF) and neutrophil function may be impaired by oxidative stress.Hypothesis: Cats with CRF have increased oxidative stress and decreased neutrophil function compared with control cats. Animals: Twenty cats with previously diagnosed renal failure were compared with 10 age-matched control cats. Methods: A biochemical profile, CBC, urinalysis, antioxidant capacity, superoxide dismutase (SOD) enzyme activity, reduced to oxidized glutathione ratio (GSH : GSSG), and neutrophil phagocytosis and oxidative burst were measured. Statistical comparisons (2-tailed t-test) were reported as mean AE standard deviation.Results: The CRF cats had significantly higher serum blood urea nitrogen, creatinine, and phosphorus concentrations than control cats, and significantly lower PCV and urine specific gravity than control cats. The GSH : GSSG ratio was significantly higher in the CRF group (177.6 AE 197, 61.7 AE 33; P o .02) whereas the antioxidant capacity was significantly less in the CRF group (0.56 AE 0.21, 0.81 AE 0.13 Trolox units; P o .005). SOD activity was the same in control and CRF cats. Neutrophil oxidative burst after Escherichia coli phagocytosis, measured as an increase in mean fluorescence intensity, was significantly higher in CRF cats than controls (732 AE 253, 524 AE 54; P o .05).Conclusions: The higher GSH : GSSG ratio and lower antioxidant capacity in CRF cats is consistent with activation of antioxidant defense mechanisms. It remains to be determined if supplementation with antioxidants such as SOD beyond the level of control cats would be of benefit in cats with CRF.

Background: Histopathology is the gold standard for the diagnosis of pancreatic disease. Laparoscopy offers a minimally invasive route by which to obtain pancreatic biopsies. Hypothesis: Laparoscopy is a safe and effective technique for evaluating the pancreas in small animal patients. Animals: Medical records of 18 dogs and 13 cats examined between 1999 and 2007 that underwent laparoscopy during which observation or biopsy of the pancreas was recorded. Methods: The database for the Laparoscopy Laboratory at Colorado State University was searched for records that contained “pancreatitis,”“pancreas,” or “pancreatic.” The presenting complaints, imaging studies, and histopathologic findings of animals were recorded. All hospital admissions were searched for animals with the same presenting complaints and of those it was determined which animals had exploratory surgery and their pancreas biopsied. Results: Thirteen cats and 18 dogs underwent laparoscopy for presumptive pancreatic disease or had the appearance of the pancreas described, pancreatic biopsies obtained, or both. In 14 animals a laparoscopic biopsy of the pancreas resulted in a histopathologic diagnosis when the sonographic findings or the gross assessment failed to do so. In 35% of the animals a biopsy of the pancreas was not obtained despite findings consistent with pancreatic disease. Those animals examined for vomiting or anorexia were significantly more likely to have a biopsy of the pancreas obtained through laparoscopy versus surgery (P < .0001). Conclusions and Clinical Importance: Laparoscopy and pancreatic biopsy is useful for evaluation of pancreatic disease.