Evaluation of a portable meter to measure ketonemia and comparison with ketonuria for the diagnosis of canine diabetic ketoacidosis

Diagnostic agreement between three point-of-care glucose and β-hydroxybutyrate meters and reference laboratory methods in stingrays

Point-of-care (POC) glucose and β-hydroxybutyrate (β-HB) meters can potentially provide rapid insight into an elasmobranch's metabolic state in clinical and field research settings. This study evaluated the diagnostic agreement of three commercial POC meters against reference laboratory methods for glucose and β-HB concentrations in stingrays. Blood was collected during anesthetized exams from 28 stingrays representing four species: cownose rays (Rhinoptera bonasus), Atlantic stingrays (Hypanus sabina), southern stingrays (Hypanus americanus), and yellow stingrays (Urobatis jamaicensis). Glucose and β-HB concentrations were measured with each POC meter using whole blood and plasma; in parallel, plasma glucose and β-HB concentrations were measured via reference laboratory methods. Agreement between POC meters and reference laboratory methods was assessed using Bland-Altman methods, Passing-Bablok regression, observed total error, percent relative error, and linear mixed effect models. Plasma glucose and β-HB concentrations determined by reference laboratory methods ranged from <20-63 mg/dL to 0.05-5.38 mmol/L, respectively. One human POC meter-the Precision Xtra-showed the greatest agreement with reference laboratory methods when measuring glucose with whole blood [mean bias and 95% CI: 0 (-3-4) mg/dL] and β-HB with plasma [mean bias and 95% CI: 0.1 (-0.04-0.2) mmol/L]. Stingray sex, weight, buffy coat, and packed cell volume did not significantly affect the agreement between POC meters and reference laboratory methods. Across all three POC meters, mean bias and imprecision for plasma β-HB concentrations were relatively small (0-0.1 mmol/L and 0%, respectively). Utilizing POC meters to measure glucose and β-HB in stingrays may be viable when reference methods are unavailable.

[Urinalysis in dogs and cats, part 1: physical and chemical urinalysis]

The urinalysis of dogs and cats is an important part of the diagnostic evaluation of urinary tract diseases as well as for the identification of systemic diseases. A routine urinalysis consists of a physical and chemical examination of the urine as well as an examination of the urine sediment. Various urine collection methods (free-catch, catheterization, cystocentesis) are available. Each method has multiple advantages and disadvantages. The appropriate method must be chosen individually for each patient depending on the emphasis of the examination. The urine should ideally be examined within 30 minutes of collection as it is prone to change due to time and storage. Physical examination of the urine consists of the determination of urine color, clarity, and specific gravity which provides information regarding the concentration of the urine. The latter is determined by refractometry and needs to be interpreted in the context of the hydration status of the patient. Chemical examination of the urine consists of the determination of the pH value and the presence of blood/hemoglobin/myoglobin, protein, glucose, bilirubin, urobilinogen, nitrite, and ketones. The use of commercially available urine dipsticks is common. These must be stored and used according to the manufacturer's instructions and when interpreting the results, veterinary aspects need to be taken into consideration. The physical and chemical examinations of the urine represent rapid and readily performable methods that provide important information for the diagnosis or the exclusion of numerous diseases.

Blood Plasma Biomarkers for Woody Breast Disease in Commercial Broilers

Woody breast (WB) myopathy results in poor muscle quality. The increasing incidence of WB over the last several years indicates a need for improved prediction or early diagnosis. We hypothesized that the use of body fluids, including blood, may be more suitable than breast muscle tissue in developing a minimally invasive diagnostic tool for WB detection. To identify potential early-age-biomarkers that may represent the potential onset of WB, blood samples were collected from 100, 4 wks old commercial male broilers. At 8 wks of age, WB conditions were scored by manual palpation. A total of 32 blood plasma samples (eight for each group of WB and non-WB control birds at two time points, 4 wks and 8 wks) were subjected to shotgun proteomics and untargeted metabolomics to identify differentially abundant plasma proteins and metabolites in WB broilers compared to non-WB control (Con) broilers. From the proteomics assay, 25 and 16 plasma proteins were differentially abundant (p < 0.05) in the 4 and 8 wks old samples, respectively, in WB compared with Con broilers. Of those, FRA10A associated CGG repeat 1 (FRAG10AC1) showed >2-fold higher abundance in WB compared with controls. In the 8 wks old broilers, 4 and 12 plasma proteins displayed higher and lower abundances, respectively, in WB compared with controls. Myosin heavy chain 9 (MYH9) and lipopolysaccharide binding protein (LBP) showed more than 2-fold higher abundances in WB compared with controls, while transferrin (TF) and complement C1s (C1S) showed more than 2-fold lower abundances compared with controls. From the untargeted metabolomics assay, 33 and 19 plasma metabolites were differentially abundant in birds at 4 and 8 wks of age, respectively, in WB compared with controls. In 4 wks old broilers, plasma 3-hydroxybutyric acid (3-HB) and raffinose concentrations showed the highest and lowest fold changes, respectively, in WB compared with controls. The blood plasma 3-HB and raffinose concentrations were confirmed with targeted biochemical assays. Blood biomarkers, such as 3-HB and raffinose, may be suitable candidate targets in the prediction of WB onset at early ages.

Updates in Feline Diabetes Mellitus and Hypersomatotropism

Flash glucose monitoring is a novel, noninvasive monitoring technique that is increasingly used in the management of small animal diabetes. This article provides guidance on the use of flash glucose monitoring in cats and demonstrates how this technique can be used in a range of feline diabetic cases, including those where management is proving challenging. Other aspects of complicated feline diabetic care are also discussed, including management of the sick diabetic cat, potassium depletion myopathy, and treatment options for cats with hypersomatotropism-associated diabetes mellitus. The use of insulin glargine 300 U/ml as a promising new long-acting insulin for diabetic cats is also discussed.

Hyperglycemic hyperosmolar state in a chimpanzee (Pan troglodytes)

A 19-year-old female chimpanzee (Pan troglodytes) presented for cachexia, acute weakness, hyporexia, icterus, and polyuria. The animal was diagnosed with a hyperglycemic hyperosmolar state, which is a well-recognized syndrome in diabetic humans that is rarely diagnosed in animals. This case documents an important and likely under-reported syndrome in non-human primates.

Chloride:Sodium Ratio May Accurately Predict Corrected Chloride Disorders and the Presence of Unmeasured Anions in Dogs and Cats

Disorders of chloride and mixed acid-base disturbances are common in veterinary emergency medicine. Rapid identification of these alterations and the presence of unmeasured anions aid prompt patient assessment and management. This study aimed to determine in dogs and cats if site-specific reference values for [Cl-]:[Na+] ratio and [Na+] - [Cl-] difference accurately identify corrected chloride abnormalities and to evaluate the predictive ability of the [Cl-]:[Na+] ratio for the identification of unmeasured anions. A database containing 33,117 canine, and 7,604 feline blood gas and electrolyte profiles was generated. Institution reference intervals were used to calculate site-specific reference values for the [Cl-]:[Na+] ratio and the [Na+] - [Cl-] difference. Contingency tables were used to assess the ability of these values to correctly identify corrected chloride disorders. Unmeasured anions were estimated by calculating strong ion gap (SIG). Continuous variables were compared using the Mann-Whitney U test. Correlations between continuous variables were assessed using Spearman's rho (rs). In dogs, site-specific reference values for the [Cl-]:[Na+] ratio correctly identified 94.6% of profiles as hyper-, normo-, or hypochloremic. For dogs with normal sodium concentrations, site-specific reference values for the [Na+] - [Cl-] difference correctly identified 97.0% of profiles. In dogs with metabolic acidosis (base deficit > 4.0), [Cl-]:[Na+] ratio and SIG were moderately but significantly negatively correlated (rs -0.592, P < 0.0001). SIG was significantly greater in dogs with metabolic acidosis and hypochloremia compared to those without hypochloremia (P < 0.0001). In cats, site-specific reference values for the [Cl-]:[Na+] ratio correctly identified 93.3% of profiles as hyper-, normo-, or hypochloremic, while site-specific reference values for [Na+] - [Cl-] difference correctly identified 95.1% of profiles. In cats with metabolic acidosis [Cl-]:[Na+] ratio and SIG were moderately significantly negatively correlated (rs -0.730, P < 0.0001). SIG was significantly greater in cats with metabolic acidosis and hypochloremia compared to those without hypochloremia (P < 0.0001). Site-specific values for [Cl-]:[Na+] ratio and [Na+] - [Cl-] difference accurately identify corrected chloride disorders in both dogs and cats and may aid identification of the presence of unmeasured anions.

Evaluation of a point-of-care electrochemical meter to detect subclinical ketosis and hypoglycaemia in lactating dairy cows

OBJECTIVES

To evaluate and validate a hand-held electrochemical meter (Precision Xtra®) as a screening test for subclinical ketosis and hypoglycaemia in lactating dairy cattle.

DESIGN

Method comparison study using a convenience sample.

PROCEDURE

Blood samples were collected into plain tubes from the coccygeal vessels of 181 Holstein cows at 2-4 weeks of lactation during summer in Iran. Blood β-hydroxybutyrate concentration (BHB) and glucose concentration were immediately measured by the electrochemical meter after applying 20 μL of blood to the reagent strip. Passing-Bablok regression and Bland-Altman plots were used to determine the accuracy of the meter against laboratory reference methods (BHB dehydrogenase and glucose oxidase).

RESULTS

Serum BHB ranged from 0.1 to 7.3 mmol/L and serum glucose ranged from 0.9 to 5.1 mmol/L. Passing-Bablok regression analysis indicated that the electrochemical meter and reference methods were linearly related for BHB and glucose, with a slope estimate that was not significantly different from 1.00. Clinically minor, but statistically significant, differences were present for the intercept value for Passing-Bablok regression analysis for BHB and glucose, and bias estimates in the Bland-Altman plots for BHB and glucose.

CONCLUSION

The electrochemical meter provided a clinically useful method to detect subclinical ketosis and hypoglycaemia in lactating dairy cows. Compared with other method validation studies using the meter, we attributed the improved performance of the electrochemical meter to application of a fixed volume of blood (20 μL) to the reagent strip, use of the meter in hot ambient conditions and use of glucose oxidase as the reference method for glucose analysis.

Point-of-Care Glucose and Ketone Monitoring

Early and rapid identification of hypo- and hyperglycemia as well as ketosis is essential for the practicing veterinarian as these conditions can be life threatening and require emergent treatment. Point-of-care testing for both glucose and ketone is available for clinical use and it is important for the veterinarian to understand the limitations and potential sources of error with these tests. This article discusses the devices used to monitor blood glucose including portable blood glucose meters, point-of-care blood gas analyzers and continuous glucose monitoring systems. Ketone monitoring options discussed include the nitroprusside reagent test strips and the 3-β-hydroxybutyrate ketone meter.

A comparison of traditional and quantitative analysis of acid-base imbalances in hypoalbuminemic dogs

OBJECTIVE

To compare the traditional (HH) and quantitative approaches used for the evaluation of the acid-base balance in hypoalbuminemic dogs.

DESIGN

Prospective observational study.

SETTING

ICU of a veterinary teaching hospital.

ANIMALS

One hundred and five client-owned dogs.

MEASUREMENTS AND MAIN RESULTS

Jugular venous blood samples were collected from each patient on admission to determine: total plasma protein (TP), albumin (Alb), blood urea nitrogen (BUN), glucose (Glu), hematocrit (HCT), Na(+) , Cl(-) , K(+) , phosphate (Pi ), pH, PvCO2, bicarbonate (HCO3 (-) ), anion gap (AG), adjusted anion gap for albumin (AGalb ) or phosphate (AGalb-phos ), standardized base excess (SBE), strong ion difference (SID), concentration of nonvolatile weak buffers (Atot ), and strong ion gap (SIG). Patients were divided in 2 groups according to the severity of the hypoalbuminemia: mild (Alb = 21-25 g/L) and severe (Alb ≤20 g/L). All parameters were compared among groups. Patients with severe hypoalbuminemia showed significant decrease in TP (P = 0.011), Atot (P = 0.050), and a significant increase in adjusted AG (P = 0.048) and the magnitude of SIG (P = 0.011) compared to animals with mild hypoalbuminemia. According to the HH approach, the most frequent imbalances were simple disorders (51.4%), primarily metabolic acidosis (84.7%) associated with a high AG acidosis. However, when using the quantitative method, 58.1% of patients had complex disorders, with SIG acidosis (74.3%) and Atot alkalosis (33.3%) as the most frequent acid-base imbalances. Agreement between methods only matched in 32 cases (kappa < 0.20).

CONCLUSIONS

The agreement between the HH and quantitative methods for interpretation of acid-base balance was poor and many imbalances detected using the quantitative approach were missed using the HH approach. Further studies are necessary to confirm the clinical utility of using the quantitative approach in the decision-making process of the severely ill hypoalbuminemic patients.

Accuracy of capillary blood 3-β-hydroxybutyrate determination for the detection and treatment of canine diabetic ketoacidosis

In human medicine, diagnosis of diabetic ketoacidosis (DKA) is usually based on measurement of capillary 3-β-hydroxybutyrate (3-HB) with a hand held ketone sensor. This study was conducted to determine if measurement of capillary 3-HB could be useful for the diagnosis and monitoring of canine DKA. Fifteen dogs with diabetic ketosis and 10 with DKA were evaluated. Paired measurements of 3-HB of capillary and venous blood samples were analysed by the electrochemical sensor and reference method. Use of capillary 3-HB measurement during DKA management was then evaluated through simultaneous measurements of capillary 3-HB, urinary AcAc and venous blood gas analysis. Good agreement between capillary and venous 3-HB measurement was detected by the electrochemical sensor and reference method. Monitoring treatment of DKA revealed a significant correlation between capillary 3-HB and acidosis markers, while no significant correlation was observed between AcAc and acidosis markers. A cut-off value of capillary blood 3-HB >3.8 mmol/L for diagnosis of DKA resulted in 70% and 92% sensitivity and specificity. The electrochemical sensor accurately measures 3-HB concentration in both capillary and venous blood samples, is accurate in diagnosing canine DKA, and appears to reflect the patient's metabolic status during DKA treatment.

Endocrine emergencies in dogs and cats

Success in treatment of endocrine emergencies is contingent on early recognition and treatment. Many endocrine diseases presenting emergently have nonspecific signs and symptoms. In addition, these endocrine crises are often precipitated by concurrent disease, further making early identification difficult. This article concentrates on recognition and emergency management of the most common endocrine crises in dogs and cats.

Point-of-care β-hydroxybutyrate measurement for the diagnosis of feline diabetic ketoacidaemia

OBJECTIVES

To evaluate accuracy and precision of a hand-held ketone meter measuring β-hydroxybutyrate and to determine its diagnostic performance to rule out ketoacidaemia in diabetic cats.

METHODS

The ketone meter was validated by calculating within-day precision at different β-hydroxybutyrate concentrations and by comparison with a laboratory method. To determine its diagnostic performance to diagnose ketoacidaemia, 217 sets of data (venous blood gas analysis and β-hydroxybutyrate measurements) were retrospectively analysed. Sensitivities and specificities were calculated with the help of receiver-operating characteristic curves.

RESULTS

The ketone meter reliably detected β-hydroxybutyrate at concentrations >0·1 mmol/L and reproducibility was acceptable. Measurements highly correlated with laboratory results (r=0·97; P<0·001), but a significant negative bias was found at high concentrations. A β-hydroxybutyrate concentration of >2·55 mmol/L had a sensitivity of 94% and a specificity of 68% for diagnosing ketoacidaemia. Many cats with high β-hydroxybutyrate concentrations and normal blood pH had an elevated chloride gap suggestive of superimposed hypochloraemic metabolic alkalosis.

CLINICAL SIGNIFICANCE

The commercially available point-of-care ketone meter Precision Xtra is a valid tool to measure β-hydroxybutyrate in diabetic cats. Concentration <2·55 mmol/L enable ketoacidaemia to be excluded and should lead to redirection of differential diagnoses.

Validation of a portable hand-held whole-blood ketone meter for use in cats

BACKGROUND

Urinary dipsticks are the most frequent method used for screening of ketones in animals, but this method has many drawbacks. In human medicine, portable meters that measure ketones in whole blood have largely replaced urinary dipsticks.

OBJECTIVE

The aim of this prospective study was to validate a portable whole-blood ketone meter for use in cats.

METHODS

Sixty-two cats (11 clinically healthy, 51 with diabetes mellitus) were included in the study. The concentration of β-hydroxybuyrate (β-HB) was measured in venous and capillary blood with a hand-held ketone meter (Precision Xceed; assay range 0-8 mmol/L) and compared with a spectrophotometric method. Precision, accuracy, and the effects of hematocrit and anticoagulants were evaluated.

RESULTS

Between-run precision using low- and high-concentration control solutions was 8.1% and 2.6%, respectively; within-run coefficient of variation determined using 12 feline blood samples was 2.8%. In the 62 cats, β-HB concentrations measured with the portable ketone meter ranged from 0-7.4 mmol/L (median 0.9 mmol/L). When β-HB concentrations measured by the portable meter were < 4.0 mmol/L there was good agreement with the reference method, but concentrations > 4.0 mmol/L were lower than those obtained by the reference method in 20 of 24 cats (83%). There was good correlation between capillary and venous measurements. Results were not affected by hematocrits from 0.17 to 0.50 L/L, but EDTA was not a suitable anticoagulant.

CONCLUSION

Measurement of β-HB concentration in peripheral or capillary blood by an easy-to-use portable ketone meter was suitable for detecting ketonemia in cats. Underestimation of β-HB concentration was observed at higher values, but results were sufficiently high to aid in diagnosing diabetic ketoacidosis.

A retrospective study of serum β-hydroxybutyric acid in 215 ill cats: clinical signs, laboratory findings and diagnoses

Serum concentrations of β-hydroxybutyric acid (sBHBA) are increased in cats with diabetes mellitus (DM), diabetic ketoacidosis (DKA) and hepatic lipidosis (HL). This study assessed sBHBA as a diagnostic tool in 215 consecutively-enrolled ill cats in the general population in a veterinary hospital. At the time of presentation, sBHBA was within the reference range in 158/215 (73.5%) cats (median 0.27; range 0.00-0.49 mmol/L) and elevated in 57/215 (26.5%) cats (median 0.87; range 0.51-21.45 mmol/L). Compared to cats with normal sBHBA, those with increased sBHBA had higher frequencies of anorexia, weight loss, icterus, polyuria/polydipsia, hyperbilirubinaemia, hypertriglyceridaemia, pancreatitis, HL, DM and DKA. They had higher concentrations of bilirubin and triglycerides and lower concentrations of potassium, chloride and total protein. There were positive correlations (P<0.01) between sBHBA and urinary glucose (r=0.42) and ketones (r=0.76), but there were no group differences in dipstick levels of urinary ketones. Cats with DM/DKA and with HL had significantly higher sBHBA compared to other cats. Receiver operator characteristics analysis of sBHBA as a predictor of HL showed that sBHBA was a good predictor of HL. Increased sBHBA occurs frequently in ill cats and provides useful diagnostic information, especially in DM/DKA and HL.

Diabetic emergencies in small animals

Diabetic ketoacidosis and hyperglycemic hyperosmolar syndrome are two serious and potentially life-threatening complications of diabetes mellitus. Understanding pathophysiology is crucial to the proper management of veterinary patients with these disorders. This article reviews the biochemical alterations contributing to these conditions, and discusses traditional and controversial management strategies.