J.M. Steiner

Early biochemical and clinical responses to cobalamin supplementation in cats with signs of gastrointestinal disease and severe hypocobalaminemia.

Domestic cats with small intestinal disease may develop cobalamin deficiency because of reduced small intestinal uptake of this vitamin. This study assessed the impact of cobalamin deficiency on biochemical and clinical findings in cats with intestinal disease. Nineteen pet cats, all with severe hypocobalaminemia (< or =100 ng/L) and histories of gastrointestinal signs, were studied. Cats received cobalamin, 250 microg SC once weekly, for 4 weeks. Biochemical indices of cobalamin availability (e.g., serum methylmalonic acid, homocysteine, and cysteine concentrations), serum feline trypsinlike immunoreactivity (fTLI) and serum folate concentrations, and clinical findings were recorded at the start of the study and after 4 weeks of cobalamin therapy. Serum methylmalonic acid (MMA) concentrations (median; range) decreased after cobalamin supplementation (5373.0; 708.5-29,329.0 versus 423.5; 214.0-7219.0 nmol/L, P < .0001). Serum homocysteine concentrations were not significantly altered (mean +/- SD 8.2 +/- 2.9 versus 10.3 +/- 4.5 micromol/L, P = .1198), whereas cysteine concentrations increased significantly (122.3 +/- 38.8 versus 191.5 +/- 29.4 micromol/L, P < .0001). Mean body weight increased significantly after cobalamin therapy (3.8 +/- 1.1 versus 4.1 +/- 1 kg, P < .01), and the average body weight gain was 8.2%. Significant linear relationships were observed between alterations in serum MMA and fTLI concentrations and the percentage body weight change (P < .05 for both, Pearson r2 = 0.26 and 0.245, respectively). Mean serum folate concentration decreased significantly (mean +/- SD 19 +/- 5 microg/L versus 15.4 +/- 6.2 microg/L, P < .001). Reduced vomiting and diarrhea were observed in 7 of 9 and 5 of 13 cats, respectively. These results suggest that cobalamin supplementation in cats with small intestinal disease and severe hypocobalaminemia is associated with normalization of biochemical test results and improvements in clinical findings in most affected cats.

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.

Comparison of Direct and Indirect Tests for Small Intestinal Bacterial Overgrowth and Antibiotic‐Responsive Diarrhea in Dogs

Controversy exists over the diagnosis of idiopathic small intestinal bacterial overgrowth (SIBO) in dogs and some clinicians use the term antibiotic-responsive diarrhea (ARD) in preference. However, whether such terms are interchangeable is not clear. To examine the relationship between duodenal bacterial numbers and a clinical response to antibiotics, SIBO and ARD were defined by nonoverlapping criteria. Quantitative duodenal juice bacteriology and indirect serum biochemical tests were used to assess small intestinal bacterial populations in 30 dogs with gastrointestinal disorders, including 9 with ARD. Serum total unconjugated bile acid (TUBA) concentrations were measured in all dogs, serum folate and cobalamin concentrations were measured in 29 of 30 dogs, and quantitative culture of duodenal juice was performed in 22 of 30 dogs. Serum TUBA concentrations also were measured in samples from 38 control dogs. Twenty of 22 affected (clinical) dogs in which quantitative bacteriology was performed were classified as having SIBO (>10(5) colony-forming units of total bacteria per milliliter of duodenal juice), but bacterial numbers did not differ significantly between dogs with ARD and dogs with other disorders. Increased folate (19/29), decreased cobalamin (16/ 29), or a combination (9/29) were common, but increased TUBA concentrations were documented in only 5 of 30 clinical dogs. Again, no significant differences were observed between dogs with ARD and those with other disorders, and a similar proportion (5/38) of controls had abnormally high TUBA concentrations. Finally, no significant differences were noted when duodenal bacteriology and TUBA concentrations were assessed before and during antibiotic therapy. These results question the utility of quantitative duodenal juice bacteriology and indirect biochemical marker tests for SIBO in the investigation of canine gastrointestinal disorders.

Urinary Biomarkers of Renal Disease in Dogs with X‐Linked Hereditary Nephropathy

BACKGROUND Sensitive and specific biomarkers for early tubulointerstitial injury are lacking. HYPOTHESIS The excretion of certain urinary proteins will correlate with the state of renal injury in dogs with chronic kidney disease. ANIMALS Twenty-five male colony dogs affected with X-linked hereditary nephropathy (XLHN) and 19 unaffected male littermates were evaluated. METHODS Retrospective analysis of urine samples collected every 2-4 weeks was performed. Urine proteins evaluated were retinol binding protein (uRBP/c), β2-microglobulin (uB2M), N-acetyl-β-D-glucosaminidase (uNAG/c), neutrophil gelatinase-associated lipocalin (uNGAL/c), and immunoglobulin G (uIgG/c). Results were correlated with serum creatinine concentration (sCr), glomerular filtration rate (GFR), urine protein : creatinine ratio, and histopathologic analysis of serial renal biopsies. Analytical validation was performed for all assays; uNAG stability was evaluated. RESULTS All urinary biomarkers distinguished affected dogs from unaffected dogs early in their disease process, increasing during early and midstages of disease. uRBP/c correlated most strongly with conventional measures of disease severity, including increasing sCr (r = 0.89), decreasing GFR (r = -0.77), and interstitial fibrosis (r = 0.80), P < .001. However, multivariate analysis revealed age, sCr, uIgG/c, and uB2M, but not uRBP/c, as significant independent predictors of GFR (P < .05). CONCLUSIONS AND CLINICAL IMPORTANCE All urinary biomarkers were elevated before sCr increased, but typically after proteinuria developed in dogs with progressive glomerular disease because of XLHN. uRBP/c measurement might be promising as a noninvasive tool for diagnosis and monitoring of tubular injury and dysfunction in dogs.

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.

Determination of serum fPLI concentrations in cats with diabetes mellitus

Diabetes mellitus (DM) is one of the most common feline endocrinopathies. Pancreatitis is a reported cause for poor control of DM in cats; however, its prevalence in diabetic cats is unknown. Measurement of serum feline pancreatic lipase immunoreactivity (fPLI) has been proposed as a sensitive and specific test for the detection of pancreatitis in cats. The aim of this study was to assess fPLI concentrations in diabetic cats and compare these with non-diabetic cats of similar age. Samples from 29 cats with DM and 23 non-diabetic cats were analysed. Serum fPLI concentrations were significantly higher in samples from diabetic cats (P<0.01). A weak association was found between serum fructosamine and fPLI concentrations (R2=0.355, P=0.015), but there was no association between fPLI concentrations and the degree of diabetic control. There were no significant differences in reported clinical signs between cats with or without DM regardless of serum fPLI concentration. This is the first study to demonstrate elevated serum fPLI concentrations in cats with DM, suggesting that pancreatitis could be a significant comorbidity in these cats.

Biological variability of C-reactive protein and specific canine pancreatic lipase immunoreactivity in apparently healthy dogs.

BACKGROUND C-reactive protein (CRP) and specific canine pancreatic lipase immunoreactivity (Spec cPL) are biomarkers of generalized or nonspecific inflammation and pancreatic inflammation in dogs, respectively. The extent of inter- and intraindividual variation over time of these analytes is not well defined in dogs. The minimal critical difference for sequential determinations of these markers (ie, the smallest change necessary to represent physiological change rather than biological variation), has not been defined. OBJECTIVES To determine the inter- and intraindividual variability (CV(G) and CV(I) ) and minimal critical difference for sequential determinations of serum CRP and Spec cPL concentrations in apparently healthy dogs. ANIMALS Eleven apparently healthy dogs owned by staff or students at a veterinary teaching hospital. METHODS Blood was collected repeatedly at varying intervals over 12 weeks. CRP and Spec cPL concentrations were determined with commercially available assays. Indices of inter-, intraindividual, and assay variability and 1-sided minimal critical differences for sequential concentrations were calculated. RESULTS For CRP, CV(G) was 90.8%, CV(I) was 115.5%, and the analytical variability (CV(A) ) was 6.3%; the index of individuality was 0.74, and 1-sided critical difference was 269.9%. For Spec cPL, CV(G) = 49.48%, CV(I) = 193.8%, CV(A) = 8.4%, index of individuality = 0.24, and 1-sided critical difference was 452.6%. CONCLUSIONS AND CLINICAL IMPORTANCE A population-based reference range is appropriate for Spec cPL, but questionable for CRP in dogs. Large changes in serial measurements of Spec cPL are necessary to infer clinical importance, more modest changes in CRP are likely to be meaningful.

Prospective Evaluation of Laparoscopic Pancreatic Biopsies in 11 Healthy Cats

BACKGROUND Definitive diagnosis of feline pancreatic disease is dependent on histologic examination of biopsies. HYPOTHESIS Laparoscopic punch biopsy of the pancreas does not significantly affect pancreatic health or clinical status of healthy cats, and provides an adequate biopsy sample for histopathology. ANIMALS Eleven healthy female domestic shorthair cats. METHODS Effects of laparoscopic pancreatic visualization alone in 5 cats compared with laparoscopic pancreatic visualization and punch biopsy in 6 cats were studied. Temperature, pulse, and respiratory rate, physical examination, and daily caloric intake were evaluated for 1 week before and 1 week after the procedure. Pain scores (simple descriptive score and dynamic interactive visual assessment score) were evaluated hourly during the 1st 6 hours postprocedure. Complete blood cell counts, serum biochemical profiles, serum feline pancreatic lipase immunoreactivity, and urine specific gravity were evaluated before the procedure and at 6, 24, and 72 hours postprocedure. One month postprocedure, during sterilization, the pancreas was reassessed visually in all cats, and microscopically in the biopsy group. RESULTS For all variables evaluated, there were no significant differences between biopsy and control cats. Re-evaluation of the pancreatic biopsy site 1 month later documented a normal tissue response to biopsy. The laparoscopic punch biopsy forceps provided high-quality pancreatic biopsy samples with an average size of 5 mm x 4 mm on 2-dimensional cut section. CONCLUSIONS AND CLINICAL IMPORTANCE Laparoscopic pancreatic biopsy is a useful and safe technique in healthy cats.

A Pilot Study to Assess Tolerability of Early Enteral Nutrition via Esophagostomy Tube Feeding in Dogs with Severe Acute Pancreatitis

BACKGROUND The putative role of the gut in amplification of systemic inflammation in acute pancreatitis is gaining credence, and intraluminal nutrition has been shown to decrease inflammation in experimental models of pancreatitis. Prepyloric feeding often is used in people with acute pancreatitis, but has not been evaluated in dogs. HYPOTHESIS Early intervention with enteral nutrition (EN) delivered proximal to the pylorus will be well tolerated in dogs with acute pancreatitis and provide justification for further larger trials. ANIMALS Ten dogs with severe acute pancreatitis in an open-label, prospective pilot study. METHODS Dogs were treated with plasma transfusion and standard care, and then consecutively assigned to receive either EN via esophagostomy tube feeding or parenteral nutrition (PN). Outcome was used to determine optimal study size for future studies, and complications were compared between the 2 groups. RESULTS A significantly greater number of vomiting or regurgitating episodes occurred in dogs receiving PN. The dogs receiving EN did not demonstrate any noticeable postprandial pain. There were more catheter-related complications in the PN group. There was no difference in outcome between the 2 treatments, and 43 dogs for each treatment would be required in future studies to determine a difference in outcome. CONCLUSIONS AND CLINICAL RELEVANCE Early EN delivered proximal to the pylorus is well tolerated in dogs with severe pancreatitis and resulted in fewer complications than PN. Prospective trials in a larger cohort are justified to fully establish the potential benefit of early EN, preferably compared with minimal enteral nutrition.

Relationships between Low Serum Cobalamin Concentrations and Methlymalonic Acidemia in Cats

BACKGROUND Serum cobalamin concentrations below reference range are a common consequence of gastrointestinal disease in cats. Serum cobalamin <or= 100 ng/L is associated with methylmalonic acidemia. OBJECTIVES To determine the prevalence of cobalamin deficiency, defined by elevated serum methylmalonic acid (MMA), in cats with serum cobalamin <or= 290 ng/L, and the optimum serum cobalamin concentration to predict cobalamin deficiency in cats. SAMPLE SET: Residual serum samples (n = 206) from cats with serum cobalamin <or= 290 ng/L. METHODS Retrospective, observational study. Serum cobalamin and folate were measured with automated assays. Serum MMA was determined by gas chromatography-mass spectrometry. Cobalamin deficiency was defined as serum MMA > 867 nmol/L. Sensitivity and specificity of serum cobalamin concentrations <or=290 ng/L for detecting MMA > 867 nmol/L were analyzed using a receiver-operator characteristic curve. RESULTS There was a negative correlation between serum cobalamin and MMA concentrations (Spearmans r=-0.74, P < 0.0001). The prevalence of MMA >or= 867 nmol/L in cats with serum cobalamin <or= 290 ng/L was 68.4%. Serum cobalamin <or= 160 ng/L had a 74% sensitivity and 80% specificity for detecting MMA > 867 nmol/L. No significant difference in serum folate concentrations was detected between affected and unaffected cats. CONCLUSIONS AND CLINICAL IMPORTANCE Elevated MMA concentrations, suggesting cobalamin deficiency, are common in cats with serum cobalamin <or= 290 ng/L. Cobalamin deficiency is clinically significant, and supplementation with parenteral cobalamin is recommended for cats with gastrointestinal disease and low serum cobalamin concentrations.