Developmental stages in microbiota, bile acids, and clostridial species in healthy puppies.

BACKGROUND: The fecal microbiota, fecal bile acid concentrations, and abundance of Clostridium perfringens and Clostridium difficile are altered in acute and chronic gastrointestinal disease in adult dogs. However, less is known in young puppies. HYPOTHESIS/OBJECTIVES: To determine composition of the fecal microbiota, assess development of fecal bile acid profiles, and determine the abundance of Clostridial species in puppies, young adult dogs, and adult dogs. ANIMALS: Healthy puppies from a whelping kennel (n = 53) and healthy client-owned dogs <1 year old (n = 20) were separated into 6 age groups, then compared to client-owned dogs over 1 year of age (n = 13). METHODS: Prospective observational study. Naturally voided fecal samples were analyzed by quantitative polymerase chain reaction to measure bacterial abundances. Fecal bile acids were quantified using gas chromatography-mass spectrometry. RESULTS: Puppies up to 5 to 6 weeks of age had increased Dysbiosis Index (median [min-max]: 5.39 [1.32-8.6], P < .001), increased abundance of C. difficile (4.1 [0.01-4.85] log DNA, P < .001), decreased secondary bile acid concentrations (0.61 [0.28-5.06] µg/mg, P = .006), and decreased abundance of C. hiranonis (0.84 [0.01-6.71], P = .005) compared to adult dogs (-4.62 [-8.36 to -0.61], 0.01 [0.01-0.01], 4.12 [0.32-8.94], and 6.02 [5.06-7.00], respectively). Secondary bile acid concentration positively correlated with C. hiranonis abundance (ρ = 0.77; P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: The increase in secondary bile acids and simultaneous decrease of C. difficile and C. perfringens after 5 to 6 weeks of age warrants further investigation into regulatory impacts that secondary bile acids could have on clostridial species in dogs.

Characteristics associated with bacterial growth in urine in 451 proteinuric dogs (2008-2018).

BACKGROUND: Urine cultures are frequently recommended to rule out infection as a postrenal cause of proteinuria. OBJECTIVE: Identify characteristics associated with bacterial growth in urine in proteinuric dogs. ANIMALS: Four hundred and fifty-one dogs admitted to a teaching hospital between January 2008 and January 2018 with urine protein-to-creatinine ratios (UPCs) >0.5. METHODS: Retrospective study included dogs with a UPC, urinalysis, and quantitative urine culture (QUC) performed within a 72-hour period by searching electronic records. Dogs with recent antimicrobial therapy, urine collected by methods other than cystocentesis, or UPC ≤0.5 were excluded. Signalment, comorbidities, serum BUN and creatinine concentrations, urinalysis findings, and QUC results were recorded. The association between these characteristics and presence of bacterial growth in urine was assessed by univariable and multivariable analysis. RESULTS: Thirty of four hundred fifty-one dogs (6.7%) had bacterial growth in urine. Of these, 18 (60.0%) had active urine sediment. Bacterial growth in urine was associated with pyuria (odd ratio [OR] 25.1, 95% confidence interval [CI] 7.9-79.6, P < .001), bacteriuria (OR 11.1, 95% CI 3.2-39.1, P < .001), and lower urinary tract disease (OR 6.7, 95% CI 1.9-23.0; P = .0028). If QUC was prompted based on these criteria, 8/451 (1.8%) of proteinuric dogs would have had undetected bacterial growth. CONCLUSIONS AND CLINICAL IMPORTANCE: The proportion of proteinuric dogs with both inactive urine sediment and bacterial growth in urine was low, suggesting that QUC might not be necessary in the evaluation of all proteinuric dogs. An active urine sediment or lower urinary tract disease should prompt QUC for proteinuric dogs.