Gastric pH and serum gastrin concentration in age-matched healthy dogs and dogs with chronic kidney disease

BACKGROUND

Gastric hyperacidity and hypergastrinemia are purported to cause gastric ulceration in dogs with chronic kidney disease (CKD); however, no published studies have evaluated gastric pH with serum gastrin concentrations in dogs with CKD.

HYPOTHESIS

To compare mean intragastric pH, mean percent pH distribution, and serum gastrin concentrations in dogs with CKD to age-matched, healthy dogs. We hypothesized there would be no difference in mean gastric pH or serum gastrin between groups.

ANIMALS

Thirteen dogs with CKD; 10 aged-matched healthy dogs.

METHODS

Prospective, case-control study. Serum chemistry, complete blood count, urinalysis, and serum gastrin concentrations were evaluated in all dogs before radiographic-assisted gastric placement of a pH capsule. Forty-eight-hour continuous gastric pH monitoring was performed in all dogs. Serum gastrin concentration, mean pH, and mean percentage time that gastric pH was strongly acidic (pH <1 and pH <2) were compared between groups using a repeated measures mixed-model ANOVA.

RESULTS

No significant differences were observed between groups for any pH measurements, including mean ± SD gastric pH (CKD, 2.37 ± 0.87; healthy, 2.39 ± 0.99; P > .05). Serum gastrin concentrations were not significantly different between groups (median [range]: CKD, 10.5 ng/dL [<10-17.1]; healthy, 10.9 ng/dL [<10-15]; P > .05).

CONCLUSIONS AND CLINICAL IMPORTANCE

Our client-owned dogs with CKD did not have lower gastric pH or higher serum gastrin concentrations compared to healthy dogs. Our results suggest that prophylactic gastric acid suppression in dogs with CKD is not warranted unless other clinical indications for use are present.

Analytical validation, sample stability, and clinical evaluation of a new high-sensitivity cardiac troponin I immunoassay for use in dogs, with comparison to a previous ultrasensitive assay

Cardiac troponin I (cTnI) is considered the gold standard biomarker for myocardial injury and shows a high degree of homology between humans and dogs. The ADVIA Centaur XP High-Sensitivity Troponin I (AC-cTnI-HS) assay has been validated for use in humans but not dogs. The study objectives were to analytically validate the AC-cTnI-HS assay in dogs, to assess correlation between the AC-cTnI-HS and a previous ADVIA Centaur TnI-Ultra (AC-cTnI-U) assay, to assess cTnI sample storage stability, and to clinically evaluate the AC-cTnI-HS assay in healthy dogs and dogs with cardiac disease. Canine serum samples were used for analytical validation. Intra- and inter-assay variability, dilutional parallelism, and spiking recovery were assessed. Samples from 196 client-owned dogs were evaluated (healthy dogs (n = 39) or dogs with congenital heart disease (n = 54), myxomatous mitral valve disease (n = 68), dilated cardiomyopathy (n = 15), or myocarditis (n = 20)). Inter- and intra-assay coefficient of variation (%CV) was between 2.8-41.4% and 3.8-30.2%, respectively, with pools with concentrations >20 pg/mL all having %CVs <10%. The observed to expected ratios for dilutional parallelism and spiking recovery experiments ranged between 92.3 and 266.7.0% and 84.3 and 108%, respectively. A strong correlation between the AC-cTnI-HS and AC-cTnI-U assays was observed (Spearman's ρ = 0.927), though a proportional bias existed, with AC-cTnI-HS assay concentrations being proportionally lower than AC-cTnI-U assay concentrations. Serum samples stored at -80°C had stable cTnI measurements for up to 2.7 years and after a single freeze-thaw cycle. Healthy dogs and dogs with congenital heart disease had significantly lower cTnI concentrations than dogs in the other three groups. The AC-cTnI-HS assay precisely, reproducibly, and accurately measures cTnI concentrations in dog serum with cTnI concentrations >20 pg/mL.

Serum cobalamin and methylmalonic acid concentrations in juvenile dogs with parvoviral enteritis or other acute enteropathies

BACKGROUND

Low serum cobalamin concentrations have been associated with ileal malabsorption in dogs with chronic enteropathy. Increased serum methylmalonic acid (MMA) concentrations indicate cobalamin deficiency on a cellular level. Few studies have evaluated serum cobalamin concentrations or methylmalonic acid concentrations in juvenile dogs with parvoviral enteritis or nonparvoviral acute enteropathies.

OBJECTIVES

Evaluate serum cobalamin and methylmalonic acid concentrations in juvenile dogs (6 weeks to 10 months old) with parvoviral enteritis or nonparvoviral acute enteropathy.

ANIMALS

Thirty-one juvenile dogs with parvoviral enteritis, 29 dogs with nonparvoviral acute diarrhea (NPVAD), and 40 healthy juvenile control dogs.

METHODS

Single-center, prospective, observational, cross-sectional study. Serum cobalamin and, when sufficient serum was available, MMA concentrations were measured.

RESULTS

Most serum cobalamin concentrations were within the adult reference interval. Serum cobalamin concentrations in healthy dogs (median, 848 ng/L; range, 293-1912 ng/L) were significantly higher than in dogs with parvoviral enteritis (P = .0002; median, 463 ng/L; range, <150-10 000 ng/L) or dogs with NPVAD (P = .02; median, 528 ng/L; range, 160-8998 ng/L). Serum MMA concentrations were not significantly different between groups (healthy dogs: median, 796 nmol/L; range, 427-1933 nmol/L; parvoviral enteritis: median, 858 nmol/L; range, 554-3424 nmol/L; NPVAD: median, 764 nmol/L; range, 392-1222 nmol/L; P = .1).

CONCLUSIONS AND CLINICAL IMPORTANCE

Juvenile dogs with parvoviral enteritis or NPVAD had lower serum cobalamin concentrations than healthy juvenile dogs. However, based on serum MMA concentrations cellular cobalamin deficiency was not apparent.

Characterization of the Fecal Microbiome in Dogs Receiving Medical Management for Congenital Portosystemic Shunts

Background

The GI microbiome has not been characterized in dogs being medically managed for congenital portosystemic shunts (CPSS).

Objectives

To characterize the fecal microbiome in a population of dogs being medically managed for CPSS.

Animals

27 client-owned dogs.

Methods

Prospective cohort study enrollment of fecal samples was performed with follow-up data collected retrospectively. The overall fecal dysbiosis index (DI) and individual bacterial abundances were determined using real-time qPCR. Medical management, clinical findings, clinicopathologic, and outcome variables were collected, and logistic regression analyses were performed to evaluate associations between these variables and overall DI and bacterial abundances. Numerical variables were evaluated with general linear models for normality and equal variance using Shapiro-Wilk test and Levene's test, respectively.

Results

All dogs were administered a hepatic diet and lactulose, while antibiotics were used in 22 (81.5%) and acid suppressants in 7 (25.9%). Seventeen dogs (63.0%) had a DI >2. The median DI in this population was 3.02 (range 4.23–8.42), and the median DI in dogs receiving and not receiving antibiotics was 4.3 (range −4.23–8.42) and 1.52 (range −1.62–5.43), respectively. No significant association between any of the analyzed variables and the DI was identified. There was a significant association between the use of metronidazole and a larger abundance of E. coli (p = 0.024).

Conclusions and Clinical Importance

Dysbiosis appears to be common in dogs that are being medically managed for CPSS, though the clinical significance remains unclear.

The cecal and fecal microbiomes and metabolomes of horses before and after metronidazole administration

Antibiotic administration can be a cause of gastrointestinal disease in horses, creating a disruption in the normal population and function of bacteria found in the hindgut. The objective of this study was to describe the changes in the cecal and fecal microbiomes and metabolomes of clinically healthy horses before and after metronidazole administration. Metronidazole (15 mg/kg BID PO) was given to five horses with cecal cannulas. The study was suspended on Day 3 due to adverse gastrointestinal effects. Cecal and fecal samples were obtained before (Days minus52, m28, m14, and 0) and after (Days 7, 14, 28, and 52) metronidazole administration. DNA was extracted from the cecal and fecal samples, and 16S rRNA genes were sequenced. Richness and evenness indices were significantly decreased by metronidazole administration in both cecal and fecal samples, but the overall composition was only significantly changed in fecal samples on Day 3 (ANOSIM, p = 0.008). The most dominant phyla were Bacteroidetes and Firmicutes in all groups examined. In fecal samples, significant changes of the phyla Actinobacteria, Spirochaetes, Lentisphaerae, and Verrucomicrobia occurred on Day 3, which correlated with clinical signs of gastrointestinal disease. The metabolome was characterized by mass spectrometry-based methods and only named metabolites were included in the analysis. Fecal, but not cecal, metabolites were significantly affected by metronidazole. The fecal metabolites affected represent diverse metabolic pathways, such as the metabolism of amino acids, carbohydrates, lipids, nucleic acids and cofactors and vitamins. Metronidazole administration has potential to cause adverse effects in horses, alters the bacterial composition of the horse’s cecal and fecal content, and the metabolome of fecal samples.

Microbiota-Related Changes in Unconjugated Fecal Bile Acids Are Associated With Naturally Occurring, Insulin-Dependent Diabetes Mellitus in Dogs

Diabetes mellitus (DM) in humans has recently been associated with altered intestinal microbiota. The consequences of intestinal dysbiosis, such as increased intestinal permeability and altered microbial metabolites, are suspected to contribute to the host inflammatory state and peripheral insulin resistance. Human diabetics have been shown to have changes in bile acid (BA) metabolism which may be detrimental to glycemic control. The purpose of this study was to examine BA metabolism in dogs with naturally-occurring, insulin-dependent DM and to relate these findings to changes in the intestinal microbiota. A prospective observational study of adult dogs with a clinical diagnosis of DM (n = 10) and healthy controls (HC, n = 10) was performed. The fecal microbiota were analyzed by 16S rRNA gene next-generation (Illumina) sequencing. Concentrations of fecal unconjugated BA (fUBA) were measured using gas chromatography and mass spectrometry. Analysis of bacterial communities showed no significant difference for any of the alpha-diversity measures between DM vs. HC dogs. Principal coordinate analysis based on unweighted Unifrac distance metric failed to show significant clustering between dog groups (ANOSIM_Unweighted: R = 0.084; p = 0.114). However, linear discriminate analysis effects size (LEfSe) detected differentially abundant bacterial taxa (α = 0.01, LDA score >2.0) on various phylogenetic levels. While Enterobacteriaceae was overrepresented in dogs with DM, the proportions of Erysipelotrichia, Mogibacteriaceae, and Anaeroplasmataceae were increased in HC dogs. Dogs with DM had increased concentration of total primary fUBA compared to HC dogs (p = 0.028). The concentrations of cholic acid and the cholic acid percentage of the total fUBA were increased (p = 0.028 and p = 0.035, respectively) in the feces of DM dogs relative to HC dogs. The levels of lithocholic acid (both absolute value and percentage of the total fUBA) were decreased (p = 0.043 and p < 0.01, respectively) in DM dogs vs. HC dogs. Results indicate that dogs with DM have both intestinal dysbiosis and associated fUBA alterations. The pattern of dysbiosis and altered BA composition is similar to that seen in humans with Type 2 DM. The dog represents a novel large animal model for advancing translational medicine research efforts (e.g., investigating pathogenesis and therapeutics) in DM affecting humans.

Fecal short-chain fatty acid concentrations and dysbiosis in dogs with chronic enteropathy

Background

Accumulating evidence shows an important relationship between the gastrointestinal (GI) microbiota and host health. Microbial metabolites are believed to play a critical role in host‐microbial interactions. Short‐chain fatty acids (SCFAs) are major end products of bacterial carbohydrate fermentation in the intestinal tract. Decreased concentrations of SCFAs have been observed in humans with GI disease. However, large‐scale clinical data in dogs are lacking.

Hypothesis/Objective

To evaluate fecal concentrations of SCFAs and the fecal microbiota in healthy control (HC) dogs and dogs with chronic enteropathy (CE).

Animals

Forty‐nine privately owned HC dogs and 73 dogs with CE.

Methods

Prospective cohort study. Fecal concentrations of SCFAs were measured using gas chromatography/mass spectrometry. Illumina sequencing and quantitative real‐time polymerase chain reaction were utilized to evaluate the fecal microbiota.

Results

Fecal concentrations (median [range] μmol/g of dry matter) of acetate were lower (P = .03) in dogs with CE (185.8 [20.1‐1042.1]) than in HC dogs (224.0 [87.7‐672.8]). Propionate were also lower (P < .001) in dogs with CE (46.4 [0.4‐227.9]) than in HC dogs (105.9 [1.6‐266.9]). Moreover, total SCFAs were lower (P = .005) in dogs with CE (268.1 [21.8‐1378.2]) than in HC dogs (377.2 [126.6‐927.0]). Dysbiosis in dogs with CE was characterized by decreased bacterial diversity and richness, distinct microbial community clustering compared with that in HC dogs, and a higher dysbiosis index.

Conclusions and Clinical Importance

Dogs with CE had an altered fecal SCFA concentration accompanied by significant changes of the fecal microbiota.

Comparison of biomarkers adiponectin, leptin, C-reactive protein, S100A12, and the Acute Patient Physiologic and Laboratory Evaluation (APPLE) score as mortality predictors in critically ill dogs

OBJECTIVES

To determine if selected serum biomarkers are superior to the acute patient physiologic and laboratory evaluation (APPLE) complete score in predicting 30-day mortality in a non-homogeneous disease population of critically ill dogs.

DESIGN

Prospective cohort study comparing the serum biomarkers adiponectin, leptin, C-reactive protein, and S100A12 concentrations between surviving and nonsurviving critically ill dogs.

SETTING

University small animal teaching hospital.

ANIMALS

Seventy critically ill dogs were prospectively recruited, and an APPLE complete score was calculated within 24 hours of being admitted to the intensive care unit. Logistic regression models were fit to estimate the association between biomarkers and 30-day survival. Results were interpreted at the 5% level of significance.

MEASUREMENTS AND MAIN RESULTS

Leptin was the only biomarker that was significantly correlated with the APPLE complete score (P < 0.001). Only the APPLE complete score (P = 0.003) and illness duration of < 1 day (P = 0.043) were significantly associated with outcome.

CONCLUSION

Based on the results of this study, there appears to be no benefit in using biomarkers over the APPLE score for disease severity stratification. Serum leptin concentration was significantly correlated with disease severity as determined by APPLE scoring. Longer duration of illness prior to admission was associated with a higher risk of death. APPLE scores were highest in dogs with infectious and immune-mediated diseases and bite wounds.

S100A12 concentrations and myeloperoxidase activities are increased in the intestinal mucosa of dogs with chronic enteropathies

Background

Intestinal mucosal S100A12 and myeloperoxidase (MPO) are inflammatory biomarkers in humans with inflammatory bowel disease (IBD). However, these biomarkers have not been studied in the intestinal mucosa of dogs with chronic enteropathies (CE), even though dogs with CE have increased S100A12 concentrations in feces and serum. This study investigated mucosal S100A12 concentrations and MPO activities in both dogs with CE and healthy Beagles. ELISA (S100A12 concentrations) and spectrophotometric methods (MPO activity) were used. The associations of both biomarkers with canine IBD activity index (CIBDAI), histopathologic findings, clinical outcome, and serum albumin concentrations were also investigated. We studied intestinal mucosal samples originating from different intestinal regions of 40 dogs with CE and 18 healthy Beagle dogs (duodenum, ileum, colon, and cecum).

Results

Compared with healthy Beagles, mucosal S100A12 concentrations in dogs with CE were significantly higher in the duodenum (p < 0.0001) and colon (p = 0.0011), but not in the ileum (p = 0.2725) and cecum (p = 0.2194). Mucosal MPO activity of dogs with CE was significantly higher in the duodenum (p < 0.0001), ileum (p = 0.0083), colon (p < 0.0001), and cecum (p = 0.0474). Mucosal S100A12 concentrations in the duodenum were significantly higher if the inflammatory infiltrate consisted mainly of neutrophils (p = 0.0439) or macrophages (p = 0.037). Mucosal S100A12 concentrations also showed a significant association with the severity of total histopathological injury and epithelial injury in the colon (p < 0.05). Mucosal MPO activity showed a significant association (p < 0.05) with the severity of total histopathological injury, epithelial injury, and eosinophil infiltration in the duodenum. There was no significant association of both biomarkers with CIBDAI or clinical outcome.

Conclusions

This study showed that both mucosal S100A12 concentrations and MPO activities are significantly increased in the duodenum and colon of dogs with CE; mucosal MPO was also increased in the ileum and cecum. Future research should focus on assessing the clinical utility of S100A12 and MPO as diagnostic markers in dogs with CE.

Measurement of CP-violating asymmetries in B0 decays to CP eigenstates

We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23x10(6) Upsilon(4S)-->BbarB decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events in which one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2beta, is derived from the decay time distributions in such events. The result is sin2beta = 0.34+/-0.20 (stat)+/-0.05 (syst).