Outcome of dogs with diabetic ketoacidosis: 127 dogs (1993-2003)

The aim of this study was to retrospectively describe the outcome of 127 dogs with naturally occurring diabetic ketoacidosis (DKA) and to examine the association between outcome of canine DKA and clinical and clinicopathologic findings. Eighty-two (65%) dogs were diagnosed with DKA at the time of initial diagnosis of diabetes mellitus (DM). Eighty-seven dogs (69%) had one or more concurrent disorders diagnosed at the time of hospitalization. Commonly identified concurrent conditions included acute pancreatitis (52, 41%), urinary tract infection (21, 20%), and hyperadrenocorticism (19, 15%). Dogs with coexisting hyperadrenocorticism were less likely to be discharged from the hospital (P = .029). Of 121 treated dogs, 89 dogs (70%) survived to be discharged from the hospital, with a median hospitalization of 6 days. Nonsurvivors had lower ionized calcium concentration (P < .001), lower hematocrit (P = .036), lower venous pH (P = .0058), and larger base deficit (P = .0066) than did survivors. Time from admission to initiation of subcutaneous insulin therapy was correlated with lower serum potassium concentration (P = .0056), lower serum phosphorus concentration (P = .0043), abnormally high white blood cell count (P = .0060), large base deficit (P = .0015), and low venous pH (P < .001). Multivariate analysis showed that base deficit was associated with outcome (P = .021). For each unit increase in the base deficit, there was a 9%) greater likelihood of discharge from the hospital. In conclusion, the majority of dogs with DKA were not previously diagnosed with DM. Concurrent conditions and electrolyte abnormalities are common in DKA and are associated with length of hospitalization. Survival was correlated to degree of anemia, hypocalcemia, and acidosis.     

Endogenous serum insulin concentration in dogs with diabetic ketoacidosis

Objective: To determine endogenous serum insulin concentration in dogs with diabetic ketoacidosis (DKA), and to compare it to endogenous serum insulin concentration in diabetic dogs with ketonuria but no acidosis (KDM), diabetic dogs with uncomplicated diabetes mellitus (DM) that did not have ketonuria or acidosis, and dogs with non‐pancreatic disease (NP). Design: Prospective study. Setting: Veterinary Hospital of the University of Pennsylvania. Animals: Forty‐four client‐owned dogs; 20 dogs with newly diagnosed diabetes mellitus (7 dogs with DKA, 6 dogs with KDM, and 7 dogs with DM) and 24 dogs with non‐pancreatic disease. Interventions: Blood and urine samples were obtained at the time of admission to the hospital. Measurements and main results: Signalment, clinical signs, physical examination findings, and concurrent disease were recorded for all dogs. Blood glucose concentration, venous blood pH, venous blood HCO3^? concentration, urinalysis, and endogenous serum insulin concentration were determined in all dogs. Dogs with DKA have significantly decreased endogenous serum insulin concentrations compared to dogs with DM (P = 0.03) and dogs with non‐pancreatic disease (P = 0.0002), but not compared to dogs with KDM (P = 0.2). Five of 7 dogs with DKA had detectable endogenous serum insulin concentrations, and 2 of these dogs had endogenous serum insulin concentration within the normal range. Conclusions: Diabetic dogs with ketoacidosis have significantly decreased endogenous serum insulin concentration compared to dogs with uncomplicated diabetes mellitus. However, most dogs with DKA have detectable endogenous serum insulin concentrations, and some dogs with DKA have endogenous serum insulin concentrations within the normal range.     

Adaptation of an automated assay for determination of beta-hydroxybutyrate in dogs using a random access analyzer

An automated method for measuring beta-hydroxybutyrate was adapted to the Ciba-Corning 550 Express trade mark random access analyzer. The assay was based on a kinetic reaction utilizing hydroxybutyrate-dehydrogenase. Beta-hydroxybutyrate concentration (mmol/L) was calculated ratiometrically using a 1.0 mmol/l standard. Canine serum, plasma, and urine were used without prior deproteinization and only a 30-microliter sample was required. The method demonstrated good linearity between 0 to 2 mmol/l of beta-hydroxybutyrate. Analytical recovery (accuracy) within these concentrations ranged from 85.8 to 113.3%. Both within-run and day-to-day precision were determined, as was specificity of the assay in the presence of a variety of interfering substances. The automated assay was rapid and economical, with reagent stability maintained for at least 2 weeks at 4 degrees C. This assay can readily be applied toward the assessment of ketoacidosis in dogs, and with further validation, other species.     

Changes of cardiac function in diabetic dogs

Objective

This study aimed to evaluate cardiac function and compare the concentration of cardiac biomarkers including cardiac troponin I (cTnI), galectin-3 (Gal-3), and N-terminal pro B-type natriuretic peptides (NT-proBNP) in diabetic and control dogs.

Accuracy of a continuous glucose monitoring system in dogs and cats with diabetic ketoacidosis

Objective – (1) To determine the ability of a continuous interstitial glucose monitoring system (CGMS) to accurately estimate blood glucose (BG) in dogs and cats with diabetic ketoacidosis. (2) To determine the effect of perfusion, hydration, body condition score, severity of ketosis, and frequency of calibration on the accuracy of the CGMS. Design – Prospective study. Setting – University Teaching Hospital. Animals – Thirteen dogs and 11 cats diagnosed with diabetic ketoacidosis were enrolled in the study within 24 hours of presentation. Interventions – Once BG dropped below 22.2 mmol/L (400 mg/dL), a sterile flexible glucose sensor was placed aseptically in the interstitial space and attached to the continuous glucose monitoring device for estimation of the interstitial glucose every 5 minutes. Measurements and Main Results – BG measurements were taken with a portable BG meter every 2–4 hours at the discretion of the primary clinician and compared with CGMS glucose measurements. The CGMS estimates of BG and BG measured on the glucometer were strongly associated regardless of calibration frequency (calibration every 8 h: r=0.86, P<0.001; calibration every 12 h: r=0.85, P<0.001). Evaluation of this data using both the Clarke and Consensus error grids showed that 96.7% and 99% of the CGMS readings, respectively, were deemed clinically acceptable (Zones A and B errors). Interpatient variability in the accuracy of the CGMS glucose measurements was found but was not associated with body condition, perfusion, or degree of ketosis. A weak association between hydration status of the patient as assessed with the visual analog scale and absolute percent error (Spearman's rank correlation, ρ=?0.079, 95% CI=?0.15 to ?0.01, P=0.03) was found, with the device being more accurate in the more hydrated patients. Conclusions – The CGMS provides clinically accurate estimates of BG in patients with diabetic ketoacidosis.     

Various protein and albumin corrections of the serum fructosamine concentration in the diagnosis of canine diabetes mellitus

Fructosamines are formed when glucose reacts non-enzymatically with amino groups on proteins, and previous studies have indicated that the serum fructosamine concentration could be of importance in the diagnosis of canine diabetes mellitus. Owing to the connection between the protein/albumin concentration and serum fructosamine concentration, it has been suggested that the serum fructosamine concentration should be corrected for the protein/albumin concentration. Thus, the purpose of the present study was to evaluate the uncorrected serum fructosamine concentration and various protein and albumin corrections of the serum fructosamine concentration in the separation of dogs with diabetes mellitus from dogs with other diseases that presented with clinical signs suggestive of diabetes mellitus. The evaluation was assisted by relative operating characteristic curves (ROC curves), which may be used to compare various diagnostic tests under equivalent conditions (equal true positive ratios or false positive ratios) and over the entire range of cutoff values. A total of 58 dogs (15 dogs with diabetes mellitus and 43 dogs with other diseases) were included in the study. Serum fructosamine concentration, serum total protein concentration and serum albumin concentration were measured in each dog, and various corrections of the serum fructosamine concentration for protein or albumin concentration were made. Comparing the ROC curves of the uncorrected and each corrected serum fructosamine concentration indicated that there was no decisive difference between the uncorrected and the corrected serum fructosamine concentrations in discriminating between dogs with and without diabetes mellitus. Hence, correcting the serum fructosamine concentration as a routine procedure cannot be advocated from the results of the study. Moreover, the sensitivity and specificity of the uncorrected serum fructosamine concentration were very high, 0.93 and 0.95, respectively, further evidence of the value of the uncorrected serum fructosamine concentration in the diagnosis of canine diabetes mellitus.Abbreviations SFC serum fructosamine concentration - SFC-P serum fructosamine concentration corrected for the actual serum total protein concentration - SFC-A serum fructosamine concentration corrected for the actual serum albumin concentration - SFC-Po serum fructosamine concentration corrected for the actual serum total protein concentration, only when the serum total protein concentration is outside the reference interval - SFC-Ao serum fructosamine concentration corrected for the actual serum albumin concentration, only when the serum albumin concentration is outside the reference interval - SFC-K serum fructosamine concentration corrected according to Kawamotoet al. (1992)     

Serum glycated albumin: Potential use as an index of glycemic control in diabetic dogs

Measurements of serum fructosamine, glycated hemoglobin, and glycated albumin (GA) complement serum glucose concentration for better management of diabetes mellitus (DM). Especially, the serum fructosamine test has long been used for diagnosing and monitoring the effect of treatment of DM in dogs. However, fructosamine tests are currently not performed in veterinary medicine in Japan. GA and fructoasmine levels have been shown to strongly correlate. However, the clinical implications of using GA remain to be elucidated. Therefore, the purpose of the current study was threefold: 1) Determine whether GA% is altered by acute hyperglycemia in normal dogs, simulating stress induced hyperglycemia; 2) Demonstrate that GA% does not dynamically change with diurnal variation of blood glucose concentration in diabetic dogs; and 3) Investigate whether GA% is capable of providing an index of glycemic control for 1–3 weeks in diabetic dogs as is the case with diabetic human patients. Our study demonstrated that serum GA% remains very stable and unaltered under acute hyperglycemic conditions (intravenous glucose injection) and in spite of diurnal variation of blood glucose concentration. Furthermore, serum GA% can reflect long-term changes (almost 1–3 weeks) in blood glucose concentration and the effect of injected insulin in diabetic dogs.     

Validation of a species-optimized enzyme-linked immunosorbent assay for determination of serum concentrations of insulin in dogs

Background: Measurement of canine serum insulin has relied on methods developed to measure human insulin. A species‐optimized test for measurement of serum insulin in dogs is now commercially available. Objective: The purpose of this study was to validate the canine ELISA for determination of serum insulin concentration in dogs. Methods: Precision was determined by evaluating intra‐ and interassay coefficient of variation (CV), and accuracy was determined by dilution and spike recovery studies. A method comparison study with samples from 34 clinically healthy dogs and 73 dogs examined for various illnesses and disorders (“patients”) was performed using the canine ELISA and an ELISA for human insulin. Biologic relevance of the canine assay was evaluated by measuring insulin in samples collected from 8 healthy dogs after administration of glucagon. A stability study was preformed with 6 samples stored at 20°C, 4–8°C, and ?20°C. Results: For the canine ELISA, intra‐ and interassay CVs were 4.3–7.8% and 4.4–7.7%, respectively. Mean recovery after dilution was 99% and recovery after spiking with porcine insulin was 116%. The canine and human ELISAs correlated well (r²=.94 for healthy dogs, r²=.88 for patient samples). After glucagon injection serum insulin concentrations increased significantly in 8 dogs. Insulin was stable for 30 days in 6 serum samples stored at ?20°C and in most samples for 8 days at 4–8°C. Insulin was stable for <3 days at room temperature (20°C). Conclusions: The new canine serum insulin ELISA had good precision and accuracy and correlated well with the previously used assay.     

Advanced glycation end products and sorbitol in blood from differently compensated diabetic dogs

Canine diabetes mellitus (DM) is a common metabolic disorder with long term complications, most of which are caused by glycosylation of structural proteins, decreases in antioxidant concentrations, altered osmotic balance and hypoxia due to impaired oxygen transport. Previous studies have demonstrated that under hyperglycemic conditions canine erythrocytes undergo swelling, probably due to activation of the polyol pathway. The present work aimed to assess the plasma concentration of advanced glycation end (AGE) products, stable Amadori-products generated by non-enzymatic glycosylation of proteins and the intracellular concentration of sorbitol, produced by the activation of polyol pathway in 34 blood samples from diabetic dogs and in 14 controls. AGE products were significantly higher (p<0.01) in plasma from diabetic dogs compared with control animals. The sorbitol concentration in erythrocytes was also significantly higher in diabetic dogs and, in particular, in poorly compensated animals and in dogs with ketonuria. In five cases that were analysed before and after clinical improvement, sorbitol concentration was found to correlate with improvement. These results suggest that non-specific glycosylation is increased and that the polyol pathway is activated in diabetic dogs in a manner that is proportionate to the severity of disease. Moreover, the concentration of AGE products and sorbitol may be useful for monitoring the onset of diabetic complications and assessing the most appropriate therapeutic approaches for management of canine DM.     

Enzyme-linked immunosorbent assay, single radial immunodiffusion, and indirect methods for the detection of failure of transfer of passive immunity in dairy calves

BACKGROUND: Confirmatory tests for failure of transfer of passive immunity (FTPI) in dairy calves require direct measurements of the serum immunoglobulin G concentration. Enzyme-linked immunosorbent assay (ELISA) has advantages over single radial immunodiffusion (SRID) in terms of cost and time. OBJECTIVES: To evaluate the agreement between ELISA and SRID, and to compare the diagnostic performance of ELISA with indirect methods, in the detection of FTPI in calves. ANIMALS: One hundred and fifteen dairy calves (aged 0-10 days) from 23 calf-rearing facilities. METHODS: Prospective, observational study. The agreement between SRID and ELISA was determined by the Bland-Altman method. Fixed bias (SRID - ELISA) was calculated. For comparison of the diagnostic performance of ELISA with indirect methods, sensitivity, specificity, and area under the curve (AUC) of receiver operating characteristic (ROC) curves were calculated at cut-off values of 500 and 1,000 mg/dL. RESULTS: The agreement between SRID and ELISA was 94%. Fixed bias (SRID - ELISA) was 140 +/- 364 mg/dL. The AUC and sensitivity of ELISA at the cut-off value of 1,000 mg/dL were higher than those of indirect methods (P<.004). The specificity of ELISA at the cut-off value of 1,000 mg/dL was not higher than that of indirect methods, except for serum total protein concentration assay. CONCLUSION AND CLINICAL IMPORTANCE: ELISA exhibited good diagnostic performance and good agreement with SRID. ELISA is an adequate method for both screening and confirmatory tests for FTPI in dairy calves at the cut-off value of 500 mg/dL.     

Exclusion of cytoplasmic fragments in flow cytometric analysis of lymph node samples from dogs with lymphoma using membrane-permeable violet laser-excitable DNA-binding fluorescent dye (DyeCycle Violet)

Background: Cytoplasmic fragments derived from fragile neoplastic lymphocytes are common in samples of lymph nodes collected from dogs with lymphoma. These cytoplasmic fragments interfere with accurate gating of target cells and quantification protocols used for flow cytometry because of their variable size and expression of lymphoid cell surface antigens on their membranes. Objective: The aim of this study was to develop a method to efficiently exclude cytoplasmic fragments from flow cytometric analysis of canine lymph nodes in which lymphoma was present. Methods: Single‐cell suspensions of neoplastic cells were prepared from biopsy samples and fine‐needle aspirates of lymph nodes from 23 dogs with lymphoma. Suspensions were stained using a violet laser‐excitable (405 nm) membrane‐permeable DNA‐binding fluorescent dye (DyeCycle Violet [DCV]), incubated with antibodies against CD3, CD5, CD21, CD22, and CD45, and then stained with 7‐amino‐actinomycin D (7‐AAD), an argon‐excitable (488 nm) membrane‐impermeable DNA‐binding fluorescent dye. Multiparameter flow cytometry was used for analysis based on selective uptake and laser‐activated fluorescence of these dyes. Results: Cytoplasmic fragments, which were DCV‐negative and CD45‐positive, and dead cells, which were positive for 7‐AAD, were efficiently separated from neoplastic cells. Conclusion: Staining with DCV is a useful method to improve flow cytometric gating methods and quantitative analyses of lymph node samples from dogs with lymphoma.     

Evaluation of IGF-I levels and serum protein profiles of diabetic cats and dogs

In this study, we measured the insulin-like growth factor (IGF)-I levels and evaluated the serum protein profiles of diabetic, insulin-treated, and healthy cats and dogs. The total IGF-I concentrations were 33.74 ± 3.4 ng/mL for normal, 25.8 ± 4.5 ng/mL for diabetic, and 180.4 ± 31.4 ng/mL for insulin-treated cats. IGF-I concentrations were 46.4 ± 6.6 ng/mL for normal, 25.1 ± 4.1 ng/mL for diabetic, and 303.0 ± 61.3 ng/mL for insulin-treated dogs. Total serum protein profiles were analyzed by SDS-PAGE. Fourteen bands ranging from 25 to 240 kDa in size were observed for cats, and 17 bands ranging from 25 to 289 kDa were observed for dogs. The densities of the bands differed among control, diabetic, and insulin-treated animals. In conclusion, we found that serum protein profiles and IGF-I concentrations were altered in both diabetic and insulin-treated animals. When judiciously interpreted in the light of other clinical and laboratory data, the techniques used in our study provide a valuable modality for measuring the severity of diabetes mellitus in dogs and cats.     

Comparison of postprandial and ceruletide serum bile acid stimulation in dogs

BACKGROUND: Postprandial (PP) serum bile acid (SBA) stimulation is an important test for detecting hepatic dysfunction in dogs. However, this test is influenced by numerous variables, and a standardized approach using an injectable cholecystokinin analog (ceruletide) may be advantageous. HYPOTHESIS: Ceruletide SBA stimulation test is more sensitive than PP SBA stimulation in dogs. ANIMALS: Animals with portosystemic shunt (PSS) (n = 11) and dogs with upper respiratory disease (URD) (n = 9) were investigated. Healthy dogs (n = 13) and dogs with other diseases (n = 17) served as controls. METHODS: All dogs underwent SBA stimulation with food and ceruletide. Stimulation blood samples were drawn at 60/120 minutes and 20/30/40 minutes, respectively. Results were compared statistically, and the sensitivity and specificity were determined with receiver-operating characteristic curves. RESULTS: Stimulated SBA were significantly higher in both study groups than in controls. For dogs with PSS, the sensitivity and specificity (>35 micromol/L) were 100% postprandially (120 minutes) and 91 and 100%, respectively, postceruletide (30 minutes). The difference between these values was not statistically significant. For dogs with URD, the sensitivity and specificity (>22 micromol/L) were 44 and 88% postprandially (120 minutes) and 100 and 88% postceruletide (30 minutes). CONCLUSIONS AND CLINICAL IMPORTANCE: Ceruletide SBA stimulation circumvents exogenous and endogenous influences associated with PP SBA stimulation. The results indicate that ceruletide SBA stimulation performs as well as PP SBA stimulation in dogs with PSS and is more sensitive for the detection of hepatic dysfunction in dogs with URD.     

Statistical Evaluation of Test Accuracy Studies for Toxoplasma gondii in Food Animal Intermediate Hosts

The availability of accurate diagnostic tests is essential for the detection and control of Toxoplasma gondii infections in both definitive and intermediate hosts. Sensitivity, specificity and the area under the receiver‐operating characteristic (ROC) curve are commonly used measures of test accuracy for infectious diseases such as toxoplasmosis. These test performance characteristics are important considerations when selecting from among a group of tests for a specific testing purpose. In this study, we reviewed statistical approaches to evaluation of tests for toxoplasmosis with and without a gold‐standard (reference) test, including use of ROC analysis and likelihood ratios which retain the diagnostic information inherent in a quantitative test result. We use previously published data from a comparison of the accuracy of serological tests for swine toxoplasmosis to demonstrate suggested methods of data analysis. We make recommendations for statistical analysis and reporting of test evaluation studies for T. gondii in food animals based on our own experiences and those of others.     

Pregnancy impairs ketone body disposal in late gestating ewes: implications for onset of pregnancy toxaemia

The impact of pregnancy on ketone body disposal during a hyperketonaemic clamp was examined by tracer isotope dilution techniques in seven 12 h fasted sheep in three reproductive states, in the dry non-gestating period, late in gestation and during early lactation. After a sampling period of 60 min under basal conditions a DL-BHB racemate solution was continuously infused intravenously for 3 h at rates of 14.3-24.3 micromol/(kg min) to elevate the D-BHB concentration in blood plasma to values between 5 and 7 mmol/l. Two separate experiments were carried out with the same sheep in each of the three reproductive states. During pregnancy three ewes were pregnant with a single lamb and four ewes carried twins. Maximal D-BHB turnover rates fell significantly in late gestation by 26% relative to early lactation and by 22% when compared with the dry non-pregnant state. Reduction of maximal D-BHB disposal rate during late gestation was accompanied by a significant 297% (p<0.005) and a non-significant 49% increase in the basal BHB concentration in blood, a non-significant 10% and 4% decrease in the rate constant of D-BHB turnover and a non-significant 24% and 13% rise in the incremented increase of D-BHB concentration per unit D-BHB infusion, relative to the dry and the lactating period, respectively. Induction of hyperketonaemia significantly lowered NEFA and glycerol concentrations in blood by 67% and 57%, respectively, compared to the pre-infusional concentrations. The magnitude of this effect was the same in all reproductive states and was explained as a direct antilipolytic action of D-BHB on adipose tissue. It is concluded that the reduced ability of the late gestating ewe to utilize D-BHB promotes hyperketonaemia. Since hyperketonaemia exerts several adverse effects, e.g. on energy balance and glucose metabolism it appears that the impairment of ketone bodies disposal in late pregnancy facilitates development of pregnancy toxaemia, especially in ewes carrying twins.