Frequency of diabetic remission, predictors of remission and survival in cats using a low-cost, moderate-intensity, home-monitoring protocol and twice-daily glargine

OBJECTIVES

The aim of the present study was to retrospectively assess remission rates and survival in diabetic cats managed using a moderate-intensity, low-cost protocol of home blood glucose measurements and insulin adjustment by clients of a cat-only practice, and to determine if predictors of remission, relapse or survival could be identified.

METHODS

The records of a cat-only practice were used to identify 174 cats with newly diagnosed diabetes managed using only pre-insulin home blood glucose measurements for insulin dose adjustments based on a protocol provided to clients aimed at maintaining pre-insulin blood glucose in the range of 6.5-11.9 mmol/l (117-214 mg/dl). Cats were excluded for the following reasons: insufficient follow-up in the records; a lack of owner compliance was recorded; they were receiving ongoing corticosteroids for the management of other conditions; they were euthanased at the time of diagnosis; or they were diagnosed with acromegaly or hyperadrenocorticism.

RESULTS

Using only pre-insulin blood glucose measurements at home to adjust the insulin dose to maintain glucose in the range of 6.5-11.9 mmol/l, 47% of cats achieved remission, but 40% of those cats relapsed. A minority (16%) of cats were hospitalised for hypoglycaemia. The survival time was significantly longer in cats in remission and Burmese cats.

CONCLUSIONS AND RELEVANCE

The cost and time burden of treating diabetic cats may cause some clients to choose euthanasia over treatment. While the highest rates of diabetic remission have been reported in studies of newly diagnosed cats treated with intensive long-acting insulin protocols and low carbohydrate diets, these protocols may not be suitable for all clients. Nearly 50% of cats with newly diagnosed diabetes achieved remission with this low-cost, moderate-intensity, insulin dosing protocol. As remission was significantly associated with survival time, discussing factors in treatment to optimise remission is important, but it is also important to offer clients a spectrum of options. No cats that started treatment in this study were euthanased because the owner did not wish to continue the diabetes treatment.

High concordance of blood glucose measurement in cats between a beta prototype glucometer device and a reference laboratory standard in a clinical setting

OBJECTIVE

The objective of this study was to evaluate the accuracy of a beta prototype version of a new portable blood glucose meter in feline patients.

ANIMALS

60 client-owned cats.

METHODS

In this prospective study, 3-mL blood samples were collected from each cat and analyzed in triplicate using a beta prototype device (AlphaTRAK 3 [AT3]) and by a reference lab standard immediately after collection. Accuracy of the AT3 device was determined in accordance with the International Organization of Standardization (ISO) 15197:2013 criteria, including Bland-Altman plotting and consensus error grid analysis. A Passing-Bablok regression analysis was also performed.

RESULTS

96% of feline measurements fell within the ISO accuracy threshold, and 100% of measurements fell within zones A and B of the consensus error grid, meeting the ISO accuracy requirements. There was no significant bias in the data according to the Bland-Altman analysis. Within the full range of glucose concentrations (20 to 750 mg/dL) the correlation coefficient between the AT3 and the reference lab standard was 0.99. There was no significant constant or proportional bias present in the data.

CLINICAL RELEVANCE

The AT3 device met the ISO requirements and is accurate for measurement of blood glucose concentrations in cats.

Use of FreeStyle Libre for continuous glucose monitoring in adult horses

OBJECTIVES

To evaluate the feasibility of using the FreeStyle Libre (a continuous glucose monitoring system [CGMS]) for instantaneous continuous monitoring of interstitial glucose in adult horses and examine the applicability and accuracy of this system in horses submitted to combined glucose-insulin test (CGIT).

DESIGN

Laboratory measurements and continuous glucose monitoring system (CGMS) readings were analyzed using a 2 × 2 factorial statistical model with repeated measures over time. This analysis assessed the effects of the test (factor 1), group (factor 2), and their interactions (test × group, test × time, and group × time). Pearson's correlation analysis was applied to blood glucose values. Mean comparisons were conducted using the t-test, and agreement between techniques was assessed via the Bland-Altman method, with a 95% confidence interval.

SETTING

Field study on private horse farms in association with a veterinary school.

ANIMALS

Ten healthy stallions were assigned to one of two groups based on their body condition scores (BCS). Group 1 (G1, n = 5) consisted of nonobese horses with a BCS of 5 or 6, while Group 2 (G2, n = 5) consisted of obese horses with a BCS of 7 or higher.

INTERVENTIONS

A CGMS sensor was attached to the dorsolateral aspect of the proximal one third of each horse's neck. Laboratory blood glucose measurements and CGMS interstitial glucose readings were compared at different time points for up to 7 days after sensor fixation. Obese horses were also submitted to CGIT on Day 4.

MEASUREMENTS AND MAIN RESULTS

A comparative analysis of glucose measurements obtained in G1 and G2 horses using the CGMS and enzymatic methods revealed significant group × time interactions (P < 0.001) and time effects (P < 0.001). No interactions were detected between group (P = 0.45), test (P = 0.62), group and test (P = 0.28), or time and test (P = 0.92). In G1 and G2, tests were significantly correlated (r = 0.84 and P = 0.00) at all time points (T0-T5). Agreement between the glucose values obtained using different methods was excellent despite a small time delay in CGMS detection of rapid changes in blood glucose.

CONCLUSIONS

It was concluded that the CGMS can be used for indirect assessment of glycemic status (ie, based on interstitial glucose measurements) in nonobese and obese adult horses submitted to CGIT.

Short-term glycemic variability in non-diabetic, non-obese dogs assessed by common glycemic variability indices

Glycemic variability (GV) refers to swings in blood glucose levels and is an emerging measure of glycemic control in clinical practice. It is associated with micro- and macrovascular complications and poor clinical outcomes in diabetic humans. Although an integral part of patient assessment in human patients, it is to a large extent neglected in insulin-treated diabetic dogs. This prospective pilot study was performed to describe canine within-day GV in non-diabetic dogs with the aim to provide a basis for the interpretation of daily glucose profiles, and to promote GV as an accessible tool for future studies in veterinary medicine. Interstitial glucose concentrations of ten non-diabetic, non-obese beagles were continuously measured over a 48-h period using a flash glucose monitoring system. GV was assessed using the common indices MAGE (mean amplitude of glycemic excursion), GVP (Glycemic variability percentage) and CV (coefficient of variation). A total of 2260 sensor measurements were obtained, ranging from 3.7 mmol/L (67 mg/dL) to 8.5 mmol/L (153 mg/dL). Glucose profiles suggested a meal-dependent circadian rhythmicity with small but significant surges during the feeding periods. No differences in GV indices were observed between day and night periods (p > 0.05). The MAGE (mmol/L), GVP (%) and CV (%) were 0.86 (± 0.19), 7.37 (± 1.65), 6.72 (± 0.89) on day one, and 0.83 (± 0.18), 6.95 (± 1.52), 6.72 (± 1.53) on day two, respectively. The results of this study suggest that GV is low in non-diabetic dogs and that glucose concentrations are kept within narrow ranges.

Impact on result interpretation of correct and incorrect selection of veterinary glucometer canine and feline settings

Veterinary glucometers should be correctly coded for the patient species; however, coding errors occur in clinical settings and the impact of such errors has not been characterized. We compared glucose concentrations in 127 canine and 37 feline samples using both canine and feline settings on a veterinary glucometer (AlphaTrak; Zoetis). All samples were measured first on the canine setting and then measured using the feline setting. Glucose concentration was also measured using a central laboratory biochemical analyzer (Cobas c311; Roche). Three data comparisons for each species were investigated: incorrectly coded glucometer vs. correctly coded glucometer, correctly coded glucometer vs. Cobas c311, and incorrectly coded glucometer vs. Cobas c311. For each comparison, the following analyses were conducted: Spearman rank correlation coefficient, Bland-Altman difference plot analysis, mountain plot analysis, and Deming regression. For clinical context, Clarke error grids were constructed. There was high positive correlation for all comparisons with both species. For all comparisons, mean difference was low (-0.7 to 0.5 mmol/L for canine samples, 1.0-2.0 mmol/L for feline samples). Incorrect glucometer coding resulted in proportional bias for canine samples and positive constant bias for feline samples, and individual differences could be large (-4.44 mmol/L for one dog, 6.16 mmol/L for one cat). Although the glucometer should be used per the manufacturer's recommendation, coding errors are unlikely to have severe adverse clinical consequences for most patients based on error grid analysis.

Interstitial glucose monitoring has acceptable clinical accuracy in juvenile dogs

OBJECTIVE

To compare the performance of an interstitial glucose monitor (IGM) versus a portable blood glucose monitor (PBGM) in sick juvenile dogs in a veterinary ICU.

ANIMALS

16 client-owned dogs admitted to the university teaching hospital under 1 year of age with systemic illness.

PROCEDURES

Paired interstitial and blood glucose samples were collected. A third glucose measurement with a reference method was obtained when IGM and PBGM values were clinically disparate. Analytical accuracy was measured by Pearson correlation and agreement statistics, including mean absolute relative difference (MARD), bias, and 95% limits of agreement. The Parkes consensus error grid analysis was performed to assess clinical accuracy.

RESULTS

159 paired glucose measurements were available for analysis. Comparison of IGM readings to PBGM measurements resulted in an MARD of 15.4% and bias of -2.6%, with the 95% limits of agreement ranging from -42.5% to 37.4%. Positive correlation between IGM and PBGM (Pearson r = 0.65) was found. On consensus error grid analysis, 100% of the pairs fell into clinically acceptable zones (74.2% in zone A, and 25.8% in zone B). When disparate IGM and PBGM readings were compared to a laboratory reference standard (n = 13), both methods resulted in high MARD and wide limits of agreement.

CLINICAL RELEVANCE

The IGM provides clinically acceptable glucose measurements compared to PBGM to monitor glucose levels in juvenile dogs in a clinical setting. Further clinical studies with a larger sample size, particularly in the hypoglycemic range, are needed to assess IGM performance in the lower glucose range.

Complications associated with a flash glucose monitoring system in diabetic dogs

Interstitial glucose monitoring systems are commonly being used in diabetic dogs. The aim of this study was to document the incidence of complications associated with the use of a flash glucose monitoring system (FGMS) in dogs. Medical records of dogs that had placement of a 14-day FGMS during a 1-year period were reviewed. Data retrieved included the number of days the sensor remained attached and functional, sensor detachment, sensor failure prior to the end of the 14-day monitoring period, and dermatologic changes at the sensor site. Descriptive statistics were used to characterize the data. Thirty-four dogs had FGMSs placed. Most [32/34 (94%)] sensors were placed over the dorsolateral aspect of the thorax caudal to the scapula. Twenty-four sensors (71%) remained attached for the full 14 days. Incidence of complications associated with FGMS use was 13/34 (38%). The most frequent complication was mild dermatologic changes at the sensor site [6/34 (18%)]. Erythema and crusting at the attachment site were common and could be related to contact dermatitis, hypersensitivity, or skin preparation prior to placement. Flash glucose monitoring systems are safe in dogs, although there are some potential complications that should be discussed with dog owners.

Assessment of the FreeStyle Libre 2 interstitial glucose monitor in hypo- and euglycemic cats

BACKGROUND

Continuous glucose monitoring systems have been validated for eu- and hyperglycemic cats. The FreeStyle Libre 2 (FSL2) is sufficiently accurate in people during hypoglycemia to guide critical treatment decisions without confirmation of blood glucose concentration (BG).

OBJECTIVES

Assess FSL2 accuracy in cats with hypoglycemia.

ANIMALS

Nine healthy, purpose-bred cats.

METHODS

Hyperinsulinemic-hypoglycemic clamps were performed by IV infusion of regular insulin (constant rate) and glucose (variable rate). Interstitial glucose concentration (IG), measured by FSL2, was compared to BG measured by AlphaTrak2. Data were analyzed for all paired measurements (n = 364) and separately during stable BG (≤1 mg/dL/min change over 10 minutes). Pearson's r test, Bland-Altman test, and Parkes Error Grid analysis respectively were used to determine correlation, bias, and clinical accuracy (P < .05 considered significant).

RESULTS

Overall, BG and IG correlated strongly (r = 0.83, P < .0001) in stable glycemia and moderately at all rates of change (r = 0.69, P < .0001). Interstitial glucose concentration underestimated BG in euglycemia, but the BG-IG difference was progressively smaller as BG decreased (12.9 ± 12.2, 8.8 ± 11.2, -3.2 ± 7.4, and -7.8 ± 5.2 mg/dL in the ranges of 80-120 [n = 64], 60-79 [n = 29], 50-59 [n = 71], and 29-49 mg/dL [n = 53], respectively).

CONCLUSIONS

Although IG underestimates BG throughout most of the hypo-euglycemic range, IG generally overestimates BG in marked hypoglycemia (<60 mg/dL). It is therefore imperative to evaluate FSL2 results in this critical range with caution.

The effect of capromorelin on glycemic control in healthy dogs

Capromorelin is a ghrelin-receptor agonist widely used as an appetite stimulant in dogs. Capromorelin disrupts glucose homeostasis in cats but information regarding its effects on canine glucose homeostasis is lacking. The study objective was to evaluate the effect of capromorelin on glucose homeostatic mechanisms in healthy dogs. Eight clinically healthy client-owned adult dogs were enrolled in this prospective, cross-over, placebo-controlled study. Dogs were randomized to receive capromorelin (Entyce, 3 mg/kg) or placebo, q24h for 3 d. A wk later, treatments were crossed over. Interstitial glucose (IG) concentrations were measured using a flash glucose monitoring system throughout. On d 1 of each treatment, blood glucose (BG), insulin, glucagon, glucose-dependent insulinotropic peptide (GIP), and glucagon-like peptide-1 (GLP-1) concentrations were measured before drug administration, then before and 30-120 min after feeding a glucose-rich diet (Ensure Plus, 21 kcal/kg). Data were analyzed as a 2-period crossover design using generalized least squares estimation. Capromorelin administration increased mean 48 h IG by10% and mean BG by 20% at 90 and 120 min post-prandially (P < 0.0001). Post-prandially, there was a time-by-treatment effect for insulin (P = 0.03) and GIP (P = 0.0002) because capromorelin doubled geometric mean insulin concentrations at 120 min and increased geometric mean GIP concentrations more rapidly than after placebo. There were no differences in glucagon or GLP-1 concentrations between treatment groups. The increase in post-prandial blood glucose was not the result of overt suppression of incretin hormone secretion. There was also no suppressive effect of capromorelin on insulin.

An ultra-long-acting recombinant insulin for the treatment of diabetes mellitus in cats

BACKGROUND

Treatment of diabetes mellitus (DM) in cats typically requires insulin injections q12h-q24h, posing a major compliance barrier for caregivers. Novel treatments enabling decreased injection frequency while maintaining safety are highly desirable. Insulin fused with feline immunoglobulin fragment crystallizable (Fc) has an ultra-long plasma half-life because it recycles through cells where it is protected from proteolysis.

HYPOTHESIS

Glycemic control can be achieved in diabetic cats with a recombinant fusion protein of a synthetic insulin and feline Fc (AKS-267c) administered SC weekly.

ANIMALS

Five cats with spontaneous DM.

METHODS

Cats previously controlled using insulin glargine q12h were transitioned to once-weekly injection of AKS-267c. The dose of AKS-267c was titrated weekly for 7 weeks based on continuous glucose monitoring. Clinical signs, body weight, fructosamine concentrations, and mean interstitial glucose concentrations (IG) were compared between baseline (week 0, on insulin glargine) and the last week of treatment. Data were assessed for normality and compared using parametric or nonparametric paired tests (as appropriate).

RESULTS

After 7 weeks of once-weekly injections, compared to baseline, there were no significant changes in clinical signs, body weight (median [range] gain, 0.1 kg [-0.1 to +0.7]; P = .5), fructosamine (-60 mmol/L [-338 to +206]; P = .6), and mean IG concentrations (change = -153 mmol/L [-179 to +29]; P = .3), and no adverse reactions were reported.

CONCLUSION

Successful control of clinical signs and maintenance of glycemia was achieved with this once-weekly novel insulin treatment. The efficacy and safety of this novel formulation should be further assessed in a large clinical trial.

Validation of a flash glucose monitoring system in outpatient diabetic cats

BACKGROUND

Interstitial glucose (IG) concentration measurement using a flash glucose monitoring system (FGMS) is a noninvasive, affordable, and informative method to regulate patients with diabetes mellitus (DM) but has not been fully validated in outpatient cats with DM.

OBJECTIVES

To further validate the FreeStyle Libre FGMS in outpatient diabetic cats.

ANIMALS

Eight client-owned cats with DM.

METHODS

Prospective observational validation study. Tissue glue was used to attach the sensor to the cat. Lin's concordance correlation coefficient (ρc ) was used to compare IG concentrations measured by the FGMS to blood glucose concentrations measured using an automated biochemistry analyzer (ABA) and point-of-care glucometer (POCG).

RESULTS

Data from 15 sensor placements in 8 cats were analyzed. Paired IG and ABA glucose concentrations (139 samples) had excellent correlation (ρc  = 0.96) as did IG and POCG glucose concentrations (142 samples, ρc  = 0.92). Sensor failure or displacement were recorded for 12/15 (80%) sensor placements. Median time of sensor activity was 7 days (range, 2-13 days).

CONCLUSIONS AND CLINICAL IMPORTANCE

In outpatient cats with DM, the FGMS-measured IG concentration correlated well with ABA-measured blood glucose concentration, but a high rate of sensor failures was observed.

Assessment of postprandial hyperglycemia and circadian fluctuation of glucose concentrations in diabetic dogs using a flash glucose monitoring system

BACKGROUND

Postprandial hyperglycemia (PPH) and circadian glucose concentration fluctuations recorded in the home environment of dogs with naturally occurring diabetes mellitus (DM) have not been reported.

OBJECTIVES

To determine if a flash glucose monitoring system (FGMS; FreeStyle Libre) can detect PPH and circadian fluctuations in glucose concentrations in dogs with variably controlled DM.

ANIMALS

Fourteen client-owned dogs with DM.

METHODS

Prospective observational study. Interstitial glucose (IG) concentrations measured by the FGMS during a 13-day study period were analyzed.

RESULTS

A total of 17, 446 FGMS IG concentrations were analyzed. For all dogs analyzed together, median IG concentration measured within 30 (288 mg/dL), 60 (286 mg/dL), 90 (285 mg/dL), and 120 (285 mg/dL) minutes of meals was each significantly higher than the median IG concentration at all other times (260 mg/dL, 259 mg/dL, 258 mg/dL, and 257 mg/dL, respectively; range, 40-500 mg/dL; P < .001 for each). Median night-time IG concentration measured from all dogs on 3,547 samples recorded between 1:00 am and 6:00 am (268 mg/dL; range, 40-500 mg/dL) was significantly higher than median IG measured on 13, 899 samples at all other time points (259 mg/dL; range, 40-500 mg/dL; P < .001).

CONCLUSIONS AND CLINICAL IMPORTANCE

The FGMS can be used for future studies of PPH and circadian fluctuations of glucose concentrations in dogs with DM in their home environment.

Investigation for correction formulas on the basis of packed cell volume for blood glucose concentration measurements obtained with portable glucometers when used in rabbits

OBJECTIVE

To determine effects of PCV on blood glucose (BG) concentration measurements obtained with a human portable blood glucometer (HPBG) and a veterinary portable blood glucometer (VPBG) on canine (cVPBG) and feline (fVPBG) settings (test methods) when used in rabbits and to develop correction formulas to mitigate effects of PCV on such measurements.

SAMPLE

48 resuspended blood samples with known PVCs (range, 0% [plasma] to 92% [plasma and packed RBCs]) from 6 healthy research rabbits (experimental sample set) and 252 historic measurements of BG concentration and PCV in 84 client-owned rabbits evaluated at a veterinary hospital (validation data set).

PROCEDURES

Duplicate measurements of BG concentration with each test method and of PCV were obtained for each sample in the experimental sample set, and the mean results for each variable for each test method and sample were compared with results from a clinical laboratory analyzer (reference method) used to determine the true BG concentration for each sample. Mean ± SD differences in measurements between the reference and test methods were calculated. Linear regression and modified Clarke error grid analysis were used to develop correction formulas for the test methods given known PCVs, and these formulas were evaluated on the validation data set with linear regression and a modified Clarke error grid.

RESULTS

Blood glucose concentrations were falsely low for cVPBG and fVPBG used on samples with PCV < 31% and were falsely high for all test methods used on samples with PCV > 43%. Compared with original measurements, formula-corrected measurements overall had better agreement with reference method measurements for the experimental sample set; however, only the formula-corrected HPBG measurements had improved agreement for the validation data set.

CONCLUSIONS AND CLINICAL RELEVANCE

Findings indicated that, in rabbits, HPBG measurements had improved accuracy with the use of the correction formula HPBG measurement of BG concentration + ([0.75 × PCV] - 15); however, the correction formulas did not improve the accuracy of VPBG measurements, and we believe that neither the cVPBG nor fVPBG should be used in rabbits.

Development and evaluation of a formula to correct blood glucose concentration measurements in hemodiluted and hemoconcentrated feline blood samples tested by use of a veterinary point-of-care glucometer

OBJECTIVE

To determine the effect of PCV on blood glucose concentration measurements in feline blood samples tested with a point-of-care (POC) glucometer and to develop and evaluate a correction formula that adjusts POC glucometer-measured blood glucose concentration (POCgluc) for a given PCV.

DESIGN

Experimental and prospective study.

SAMPLE

Blood samples from 4 healthy and 16 hospitalized cats.

PROCEDURES

Heparinized blood samples from healthy cats were processed into packed RBCs and plasma. Packed RBCs were resuspended with plasma to achieve PCVs ranging from 0% to 87%. Duplicate PCV and POCgluc measurements were obtained for each suspension. Plasma glucose concentration as measured by a clinical laboratory biochemical analyzer (LABgluc) was assessed; results were compared with the POCgluc. A formula to correct POCgluc measurements for PCV was developed. Blood samples from hospitalized cats were used to evaluate the formula.

RESULTS

For each healthy cat, LABgluc values were similar for all PCVs; the mean difference between POCgluc and LABgluc at PCVs outside a range of 35% to 55% was significant. Mean differences between POCgluc and LABgluc were 24.3 and 41.5 mg/dL, whereas mean differences between corrected POCgluc and LABgluc were 3 and 25.9 mg/dL for samples from healthy and hospitalized cats, respectively. Correlation between corrected POCgluc and LABgluc was stronger than that between POCgluc and LABgluc for samples from healthy and hospitalized cats.

CONCLUSIONS AND CLINICAL RELEVANCE

The POCgluc did not reflect LABgluc in hemodiluted or hemoconcentrated feline blood samples. Use of a correction formula appeared to reduce this error. Additional studies are needed to evaluate the frequency with which this correction formula might prevent clinical errors. (J Am Vet Med Assoc 2019;254:1180-1185).

Effect of sensor location in dogs on performance of an interstitial glucose monitor

OBJECTIVE To identify variations in glucose values concurrently obtained by use of a continuous glucose monitoring system (CGMS) at the same site, reliability of results for each site, lag time for each site, and influence of site thickness on CGMS accuracy. ANIMALS 8 random-source research dogs. PROCEDURES In experiment 1, 8 CGMS sensors were implanted bilaterally at 1 site (4 sensors/side) in 4 dogs. In experiment 2, 2 CGMS sensors were implanted bilaterally at each of 4 sites (1 sensor/side) in 8 dogs; 4 of those 8 dogs then were subjected to a glycemic clamp technique. The CGMS results were compared among sensors and with criterion-referenced results during periods of euglycemia for all 8 dogs and during hyperglycemia and hypoglycemia for 4 dogs during the glycemic clamp procedure. RESULTS Differences (median, -7 mg/dL; interquartile range [IQR], -18.75 to 3 mg/dL) between CGMS and criterion-referenced glucose concentrations differed significantly among dogs and sites; during euglycemia, they were not different from the expected normal variation between multiple sensors concurrently implanted at the same site. Differences (median, -35 mg/dL; IQR, -74 to -15 mg/dL) between CGMS and criterion-referenced concentrations were greater during changes in glucose concentrations. Thoracic sensors were most accurate but had the shortest mean functional life. CONCLUSIONS AND CLINICAL RELEVANCE Significant differences were detected between CGMS and criterion-referenced glucose concentrations. Overall clinical utility of CGMS was acceptable at all sites, with most of the values from all sensors, sites, and dogs meeting guidelines for point-of-care glucometers.

Home monitoring of the diabetic cat

Many owners are able and willing to perform home monitoring of blood glucose concentrations in diabetic cats. Once owners are familiar with the technique, they appreciate its advantages and show long-term compliance. The success of home monitoring hinges greatly on careful preparation and instruction of the owner. Owners must have ready access to veterinary support if needed. Initially, most owners call for advice, and several of them need repeated explanation or demonstration of the procedure. The frequency of re-evaluations of the diabetic cats by veterinarians is not affected by home monitoring. One of its major advantages is that it enables frequent generation of blood glucose curves. In complicated cases, more than one curve can, therefore, be performed at home before a treatment decision is made. According to preliminary data cats managed with home monitoring may have better glycaemic control than those managed without. However, those results need to be confirmed in a large group of cats.

Evaluation of portable blood glucose meters using canine and feline pooled blood samples

This study evaluated the accuracy and reproducibility of a human portable blood glucose meter (PBGM) for canine and feline whole blood. Reference plasma glucose values (RPGV) were concurrently measured using glucose oxidation methods. Fifteen healthy dogs and 6 healthy cats were used for blood sampling. Blood glucose concentrations and hematocrits were adjusted using pooled blood samples for our targeted values. A positive correlation between the PBGM and RPGV was found for both dogs (y = 0.877, x = -24.38, r = 0.9982, n = 73) and cats (y = 1.048, x = -27.06, r = 0.9984, n = 69). Acceptable results were obtained in error grid analysis between PBGM and RPGV in both dogs and cats; 100% of these results were within zones A and B. Following ISO recommendations, a PBGM is considered accurate if 95% of the measurements are within ± 15 mg/dl of the RPGV when the glucose concentration is <100 mg/dl and within ±15% when it is ≥100 mg/dl; however, small numbers of samples were observed inside the acceptable limits for both dogs (11%, 8 of 73 dogs) and cats (39%, 27 of 69 cats). Blood samples with high hematocrits induced lower whole blood glucose values measured by the PBGM than RPGV under hypoglycemic, normoglycemic, and hyperglycemic conditions in both dogs and cats. Therefore, this device is not clinically useful in dogs and cats. New PBGMs which automatically compensate for the hematocrit should be developed in veterinary practice.

Home-monitoring of blood glucose in cats with diabetes mellitus: Evaluation over a 4-month period

Home-monitoring of blood glucose concentrations has recently been introduced to owners. The objectives of this study were to investigate the feasibility of home-monitoring of blood glucose in diabetic cats by owners, the problems encountered and to compare glucose concentrations at home with those measured in the hospital. Twelve of 15 cat owners were able to generate glucose curves over the study period of 4 months. Most problems were related to restraining the cat, generating negative pressure with the lancing device and producing a blood drop. In the majority of cases, these problems could be resolved during the study. Blood glucose concentrations in the clinic tended to be lower than at home; some of the differences were significant. No association between tolerance of the procedure and blood glucose concentrations measured at home was found. We, therefore, assume that the lower glucose levels in the hospital were caused by lack of food intake. In 38% of cases, treatment based on hospital curves would have been different from that based on home curves. Home-monitoring appears to be a valuable tool in the management of cats with diabetes mellitus. One of its major advantages is that it enables frequent generation of blood glucose curves, which is of particular importance in cats that are difficult to regulate.

Usefulness of whole blood, plasma, peritoneal fluid, and peritoneal fluid supernatant glucose concentrations obtained by a veterinary point-of-care glucometer to identify septic peritonitis in dogs with peritoneal effusion

OBJECTIVE

To evaluate the usefulness of a veterinary point-of-care glucometer for identification of septic peritonitis in dogs with peritoneal effusion (PE).

DESIGN

Prospective clinical evaluation.

ANIMALS

39 dogs with PE.

PROCEDURES

Blood and peritoneal fluid convenience samples were collected concurrently in all dogs at the time of initial evaluation. A veterinary point-of-care glucometer was used to measure glucose concentration in heparinized whole blood, plasma, peritoneal fluid, and peritoneal fluid supernatant samples. Seventeen dogs had confirmed septic peritonitis, and 22 dogs had nonseptic PE. Sensitivity, specificity, positive and negative predictive values, and accuracy of identification of dogs with septic peritonitis were calculated for glucose concentration differences for whole blood versus peritoneal fluid (WB-PF), plasma versus peritoneal fluid (P-PF), and plasma versus peritoneal fluid supernatant (P-PFS).

RESULTS

With a cutoff of > 20 mg/dL, the glucose concentration difference for WB-PF was an insensitive indicator of septic peritonitis (sensitivity, 41.2%; specificity, 100%). In comparison, the glucose concentration differences for P-PF and P-PFS had a higher sensitivity for septic peritonitis (88.2% and 82.4%, respectively) but a lower specificity (80% and 77.8%, respectively). With a glucose concentration difference cutoff of ≥ 38 mg/dL, specificity, positive predictive value, and accuracy of P-PF and P-PFS improved.

CONCLUSIONS AND CLINICAL RELEVANCE

Determination of the glucose concentration difference for WB-PF with the veterinary point-of-care glucometer was not useful in identifying all dogs with septic peritonitis. A glucose concentration difference of ≥ 38 mg/dL for P-PF or P-PFS, however, supported an accurate diagnosis of septic peritonitis in dogs with PE.

Correlation between glucose concentrations in serum, plasma, and whole blood measured by a point-of-care glucometer and serum glucose concentration measured by an automated biochemical analyzer for canine and feline blood samples

OBJECTIVE

To investigate the correlation between glucose concentrations in serum, plasma, and whole blood measured by a point-of-care glucometer (POCG) and serum glucose concentration measured by a biochemical analyzer.

DESIGN

Prospective clinical study.

SAMPLES

96 blood samples from 80 dogs and 90 blood samples from 65 cats.

PROCEDURES

Serum, plasma, and whole blood were obtained from each blood sample. The glucose concentrations in serum, plasma, and whole blood measured by a POCG were compared with the serum glucose concentration measured by a biochemical analyzer by use of the Lin concordance correlation coefficient (ρc) and Bland-Altman plots.

RESULTS

For both canine and feline samples, glucose concentrations in serum and plasma measured by the POCG were more strongly correlated with the serum glucose concentration measured by the biochemical analyzer (ρc, 0.98 for both canine serum and plasma; ρc, 0.99 for both feline serum and plasma) than was that in whole blood (ρc, 0.62 for canine samples; ρc, 0.90 for feline samples). The mean difference between the glucose concentrations determined by the biochemical analyzer and the POCG in serum, plasma, and whole blood was 0.4, 0.3, and 31 mg/dL, respectively, for canine samples and 7, 6, and 32 mg/dL, respectively, for feline samples.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that use of a POCG to measure glucose concentrations in serum or plasma may increase the accuracy and reliability of diagnostic and treatment decisions associated with glucose homeostasis disorders in dogs and cats.

Evaluation of three point-of-care meters and a portable veterinary chemistry analyzer for measurement of blood glucose concentrations in black-tailed prairie dogs (Cynomys ludovicianus)

OBJECTIVE

To compare blood glucose concentrations of black-tailed prairie dogs (Cynomys ludovicianus) measured by use of a variety of portable analyzers with results from a laboratory biochemistry analyzer.

SAMPLE

Venous blood samples (3 mL) obtained from each of 16 healthy black-tailed prairie dogs.

PROCEDURES

A portion of each blood sample was used to measure glucose concentrations by use of an amperometric human point-of-care glucometer and a colorimetric species-specific portable blood glucose meter designed for veterinary use with both canine (code 5) and feline (code 7) settings. The remainder of each blood sample was placed into 2 tubes (one contained lithium heparin and the other contained no anticoagulant). A portable veterinary chemistry analyzer (PVCA) and a handheld analyzer were used to measure glucose concentration in heparinized blood. Serum glucose concentration was measured in the remaining portion by use of a biochemistry analyzer. A general linear mixed models approach was used to compare glucose concentrations and measurement bias obtained with the various measurement methods.

RESULTS

Measurement bias and differences in mean glucose concentrations were apparent with all measurement methods. In particular, the veterinary glucometer, whether used on the canine or feline setting, overestimated mean glucose concentrations, whereas the human glucometer, PVCA, and handheld analyzer underestimated mean glucose concentrations relative to the concentration obtained with the biochemistry analyzer.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that none of the measurement methods provided consistently accurate blood glucose concentrations of black-tailed prairie dogs, compared with values determined with a biochemistry analyzer.

Heimmonitoring des Blutglukosespiegels durch Besitzer diabetischer Hunde und Katzen

Generation of blood glucose curves is essential to monitor glycemic control in dogs and cats with diabetes mellitus. Up till now blood collection and blood glucose measurements could only be performed in a hospital. However, glucose concentrations measured in a hospital environment can markedly differ from concentrations measured at home, due to reduced appetite, different activity level and stressful handling. At the Clinic of Small Animal Internal Medicine, University of Zurich, a new method to collect capillary blood from the ear and to measure blood glucose by means of a portable glucose meter has been developed. This method enables owners of diabetic dogs or cats to determine blood glucose concentrations and generate blood glucose curves at home. Three cases demonstrate, how much blood glucose concentrations at home may differ from those in the hospital and how home monitoring can help to establish diabetic control in dogs and cats.

Monitoring methods for dogs and cats with diabetes mellitus

Effective monitoring is essential for the management of dogs and cats with diabetes mellitus. However, methods for evaluating glycemic control must be tailored to meet both the needs of the patient and the expectations of the owner. This article discusses the philosophies that drive blood glucose monitoring in veterinary diabetics and review common practices. The advantages and limitations of the various options are presented.

Feline diabetes mellitus: diagnosis, treatment, and monitoring

Advances in the treatment and monitoring of diabetes mellitus in humans are being applied to feline patients. The authors present the current approaches to the treatment of diabetic cats as well as their experience with the use of new monitoring technology.

Retrospective study of owners' perception on home monitoring of blood glucose in diabetic dogs and cats

Home monitoring of blood glucose (HMBG) concentrations has been recommended in the monitoring of human diabetics for 3 decades. During the last number of years, it also gained popularity in long-term follow-up of diabetic cats and dogs. The aim of this retrospective study was to evaluate the practical feasibility of and identify the major problems encountered with HMBG in diabetic pets. A standard questionnaire was filled in by owners of 9 diabetic pets monitored with HMBG. The need for more than 1 puncture to obtain a blood drop, the creation of a sufficient blood drop, the need for assistance in restraining the pet, and the resistance of the pet were the most frequently encountered problems during HMBG. The major obstacles for the owners to start with HMBG were also identified. In conclusion, HMBG is a practical and simple technique for most owners and, overall, owners were satisfied.

Evaluation of a continuous glucose monitoring system in cats with diabetes mellitus

A continuous glucose monitoring system (CGMS) was evaluated in 14 cats with naturally occurring diabetes mellitus. The device measures interstitial fluid glucose continuously, by means of a sensor placed in the subcutaneous tissue. All cats tolerated the device well and a trace was obtained on 15/16 occasions. There was good correlation between the CGMS values and blood glucose concentration measured using a glucometer (r=0.932, P<0.01). Limitations to the use of the CGMS are its working glucose range of 2.2-22.2 mmol/l (40-400 mg/dl) and the need for calibration with a blood glucose measurement at least every 12 h. When compared to a traditional blood glucose curve, the CGMS is minimally invasive, reduces the number of venepunctures necessary to assess the kinetics of insulin therapy in a patient and provides a truly continuous glucose curve.

Evaluation of long-term home monitoring of blood glucose concentrations in cats with diabetes mellitus: 26 cases (1999–2002)

OBJECTIVE

To evaluate owner compliance with longterm home monitoring of blood glucose concentrations in diabetic cats and assess the influence of home monitoring on the frequency of reevaluation of those cats at a veterinary hospital.

DESIGN

Retrospective study.

ANIMALS

26 cats with diabetes mellitus.

PROCEDURE

Medical records of diabetic cats for which home monitoring was undertaken were reviewed, and owners were contacted by telephone. Signalment, laboratory test results, insulin treatment regimen, details of home monitoring, clinical signs during treatment, frequency of follow-up examinations, and survival times were evaluated.

RESULTS

Monitoring of cats commenced within 12 weeks (median, 3 weeks) after initial evaluation; 8 owners were unable to perform home monitoring, and 1 cat was euthanatized after 1 week. In 17 cats, duration of home monitoring was 4.8 to 46.0 months (median, 22.0 months); 6 cats died after 7.0 to 18.0 months (median, 13.0 months). In 11 cats, home monitoring was ongoing at completion of the study (12.0 to 46.0 months' duration). Fourteen owners completed blood glucose curves every 2 to 4 weeks. Cats managed with home monitoring received higher dosages of insulin, compared with cats that were not monitored. Four of 17 cats managed by home monitoring had transient resolution of diabetes mellitus for as long as 1 year. Home monitoring did not affect the frequency of reevaluation at the veterinary hospital.

CONCLUSIONS AND CLINICAL RELEVANCE

Owner compliance with long-term home monitoring appeared to be satisfactory, and home monitoring did not affect the frequency of reevaluation of patients by veterinarians.

Evaluation of a continuous glucose monitoring system in diabetic dogs

The generation of a blood glucose curve is important for assessing the response to insulin therapy in diabetic dogs. Disadvantages of this technique include patient discomfort and the potential for missing transient hypo- or hyperglycaemic episodes. The aim of the current study was to evaluate a continuous glucose monitoring system (CGMS) for use in diabetic dogs. Interstitial fluid glucose concentrations were recorded in 10 diabetic dogs, every five minutes for up to 48 hours, using a subcutaneous sensor attached to the CGMS device. Blood glucose concentrations were measured simultaneously using a glucometer. The correlation between interstitial fluid and blood glucose values was 0.81 (P < 0.01). The largest discrepancies between the two sets of data were seen during the one- to three-hour period following feeding, suggesting that postprandial hyperglycaemia might not be reflected in the interstitial fluid. The authors conclude that the CGMS is a potentially valuable tool in the management of canine diabetic patients.

Home monitoring of blood glucose concentration by owners of diabetic dogs

The objective of this study was to investigate whether home monitoring of blood glucose of diabetic dogs by owners would be possible on a long-term basis. The owners of 12 diabetic dogs were each asked to generate four glucose curves by taking capillary blood samples from their dog's ear, at three- to four-week intervals. Within one week of each curve being produced by the owner, an additional curve was produced by a veterinarian in the hospital. Ten owners were able to generate blood glucose curves; three of them needed a second demonstration, and two telephoned for further guidance. The blood glucose concentrations obtained from the first two 'hospital' curves were significantly lower than those measured at home. Overall, in 42 per cent of cases, the treatment based on the hospital curves would have been different from that based on 'home' curves. The results of this study indicate that the majority of owners were able and willing to perform long-term monitoring of the blood glucose concentrations of their dogs.

Home monitoring of the diabetic pet

Home monitoring of the diabetic pet is a challenging proposition for many pet owners. Diabetes, unlike many other diseases, requires that the client, not the veterinarian, treat the disease. It is crucial that veterinarians reinforce and educate clients that successful treatment of diabetes mellitus will depend solely on the client's actions throughout the course of the treatment. This article provides guidelines on educating clients in the home monitoring process. This commonsense approach covers elements of in-home monitoring, including general appearance, clinical signs, behavior changes, feeding schedules, and medication administration. Additionally, thorough explanation is provided for clients who wish to take a more active role in obtaining and monitoring blood and urine chemistry values. This information is provided to assist the veterinary technician and veterinarian in educating clients of their responsibility in treating this disease.

Measurement of capillary blood glucose concentrations by pet owners: a new tool in the management of diabetes mellitus

Recently a new method for capillary blood sampling from the ears of dogs and cats was described, which allows the measurement of glucose concentration by means of portable glucose meters. The authors of this report evaluated the suitability of this method for use by pet owners and the potential technical problems. The owners of seven healthy dogs and seven healthy cats were asked to perform two glucose curves (measuring blood glucose concentration every 2 hours for a total of 12 hours). All dog owners and three cat owners were able to perform a reliable blood glucose curve. The most frequently encountered problems were inadequate formation of a blood drop due to excessive digital pressure on the pinna, repeatedly depressing the plunger of the lancet device instead of allowing the negative pressure to slowly build up, and failure to fill the test strip up to the mark. The authors conclude that these steps of the procedure need to be stressed during technique demonstration and that home monitoring of blood glucose concentrations may serve as a new tool in the management of diabetic dogs and cats.

Portable blood glucose meters as a means of monitoring blood glucose concentrations in dogs and cats with diabetes mellitus

The use of portable blood glucose meters (PBGM) has become common in veterinary medicine as a rapid means of monitoring animals' blood glucose in a variety of medical conditions. These hand-held monitors allow for diagnostic and therapeutic decisions to be made quickly and relatively inexpensively using only a small amount of blood. Both in conditions resulting in hyperglycemia, such as diabetes mellitus, and in those resulting in hypoglycemia, such as sepsis or the presence of an insulinoma, veterinarians have come to rely on PBGM to provide critical information on the status of their animal patients. In particular, PBGM are frequently used to measure individual blood glucose values in an animal over a period to create a blood glucose curve when evaluating the effectiveness of insulin therapy in diabetic dogs and cats.

Field method for monitoring blood glucose in beef cattle

The purpose of this study was to determine the applicability of the Accu-Chek Easy (ACE) human self-monitoring system for monitoring glycemic status in cattle. The ACE method was compared with the Yellow Springs Instrument (YSI) analytical laboratory method in two studies. A preliminary study (62 samples) and a primary study (434 samples) involved a nine-fold range and a 10-fold range, respectively, of glucose concentrations obtained during the acute phase response of growing beef cattle to injections of varying dosages of endotoxin. The ACE monitoring method compared with the YSI analytical method resulted in similar patterns of glucose concentration change, similar ranking of glucose means across endotoxin dosages during hyper-and hypoglycemia, and a close relationship between paired YSI and ACE concentrations from common samples. The ACE method identified all nine animals that displayed hypoglycemic distress during the acute phase response to endotoxin injection. The relationship between the YSI analytical method and the ACE monitoring method was found to be nonlinear (YSI = -38.2+13.6.ACE.50; R2 = .99; Sy.x = 7.3 mg/dL), and the use of this equation to predict YSI values from ACE values in an independent data set resulted in linearity when YSI was regressed on the predicted YSI values (YSI = -.78+1.00. Predicted YSI; R2 = .87; Sy.x = 6.9 mg/dL). Even though variation seemed greater for ACE than for YSI, we concluded that a system developed for human self-monitoring of blood glucose, such as the ACE, can be used to monitor the glycemic status of cattle.

Home management of cats and dogs with diabetes mellitus. Common questions asked by veterinarians and clients

Home management of the insulin-dependent diabetic pet can be confusing and frustrating for many pet owners. This article addresses many of the common concerns of pet owners, as well as issues of interest for the veterinarian regarding insulin therapy and client communication.

Long-term monitoring of the diabetic dog and cat. Clinical signs, serial blood glucose determinations, urine glucose, and glycated blood proteins

Management of diabetic dogs or cats requires the use of all available monitoring technology (Fig. 6). First, one should ask questions about the clinical control of DM. Are the clinical signs of DM resolved, and is the owner satisfied with insulin therapy? Other important questions would include: Is the dog or cat developing long-term complications of diabetes such as neuropathies or cataracts? Is body weight remaining stable? Is the dog or cat showing any signs of hypoglycemia? One should determine if the blood glucose curves are close to ideal for the type of insulin being administered. Urine glucose and ketones should be negative or trace as assessed by the at-home monitoring by the owner. In the problem diabetic, long-term glucose control can be assessed by serum fructosamine or glycosylated hemoglobin determinations. Regulation of the diabetic patient is accomplished when the owner is satisfied with the therapy and when the serum glucose monitoring parameters are acceptable.