Variability of Symmetric Dimethylarginine in apparently healthy dogs

Background: Symmetric dimethylarginine (SDMA) is a screening tool for early kidney dysfunction and monitoring treatment in cases of chronic kidney disease (CKD). There are no current studies describing the suitability of this test for use with published populationbased reference intervals. Hypothesis/Objectives: To determine the components of biological variability, the index of individuality (IOI), the critical difference between sequential measurements (CD) and the number of measurements required to assess the homeostatic set point (HSP), for both SDMA and serum creatinine (sCr), in apparently healthy dogs. Animals: Twenty apparently healthy adult dogs owned by clients or staff at a veterinary teaching hospital. Methods: Prospective, observational study. Blood was collected from each dog on 9 occasions, and SDMA and sCr were measured in duplicate using commercially available assays. Results: SDMA and sCr had intermediate and low IOI values of 0.87 and 0.28, respectively. The CD of SDMA and sCr, was 1.34 mg/dL and 0.89 mmol/L, respectively. The sample numbers required for estimation of an individual’s HSP (with 90 and 95% CI) for SDMA and sCr were 8 and 45, and 2 and 12 sequential measurements, respectively. Conclusions and Clinical Importance: Based on our findings, in comparison to sCr, SDMA is better suited for use with population based reference intervals. False-negative test results could occur when comparing a single test result from an individual to such intervals. Ideally CD should be used with sequential measurements

A severity score for spontaneous canine acute pancreatitis.

To derive a severity score for spontaneous canine acute pancreatitis applicable to general practice.Cohort study of canine pancreatitis cases.Cases (n = 68) of spontaneous canine acute pancreatitis presented to general practitioners were identified among accessions to Veterinary Pathology Services Brisbane. The primary veterinarian was surveyed by telephone to ascertain the outcome of each case. Scores were assigned for extent of hyperamylasaemia, hyperlipasaemia and number of organ systems other than the pancreas compromised. The probability of mortality with each score of each analyte was calculated. The strength of interaction between scores for each analyte and mortality rate was assessed by chi-square analysis where appropriate. Relationships between the organ system score, other physiological variables and likelihood of euthanasia were analysed.Scores derived mathematically from analysis of enzyme activities had poor abilities to predict mortality. The score based upon the number of organ systems compromised showed good ability to predict mortality and the interaction between the organ system score and mortality rate was significant by chi-square analysis (P < 0.01). Distribution of data within the amylase and lipase scores was not compatible with chi-square analysis.Assessment of severity of spontaneous canine acute pancreatitis using pancreatic enzyme activities is potentially inaccurate. The use of a severity score based upon organ system compromise was more accurate in determining the likelihood of mortality in spontaneous canine acute pancreatitis. This is compatible with the hypothesis that severe canine acute pancreatitis is a multiple organ failure syndrome