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

Comparison of a human portable blood glucose meter and automated chemistry analyser for measurement of blood glucose concentrations in healthy dogs

Blood glucose measurement is one of the most commonly performed clinical diagnostic tests used to monitor glycaemia in several animal diseases. Usually, these laboratory analyses are performed on blood venous samples in remote laboratories, and the results are delayed, at best. The use of portable glucometers could evidently solve many constraints but veterinary‐use glucometers are not usually available. The present study aimed to compare blood glucose levels obtained by Bionime glucometer to the reference method using glucose oxidase. Venous blood was collected from a total number of 140 healthy dogs (72 males and 68 females), of different breeds (28 German Shepherd, 27 Pitt bull, 21 Boxer, 24 Rottweiler and 40 cross‐bred dogs) and different ages (range: 3 months–14 years) for glucose measurement using the reference laboratory method. Capillary blood samples were used to conduct a glucose measurement with a human‐use glucometer. Our results revealed that there was no significant difference between the mean capillary blood glucose (CBG) measured with the human‐use glucometer (5.06 ± 0.84 mmol/L) and the mean venous blood glucose (VBG) measured with the laboratory reference method (4.90 ± 0.73 mmol/L) (p = 0.42). Similarly, there was no significant difference of the mean CBG and VBG in male dogs (5.11 ± 0.88 and 4.97 ± 0.75 mmol/L, respectively) and female dogs (5.01 ± 0.81 and 5.07 ± 0.72 mmol/L, respectively) (p = 0.73 and 0.21, respectively), and no correlation to neither age (5.43 ± 0.90 and 5.20 ± 0.70 mmol/L in 3 to 6 month‐old dogs, 5.03 ± 0.82 and 4.94 ± 0.79 mmol/L in 6 months to 1 year‐old, 4.94 ± 0.67 and 5.13 ± 0.66 mmol/L in 1 to 4 year‐old dogs; 4.88 ± 0.94 and 4.80 ± 0.75 mmol/L in dogs older than 4 years, respectively, p < 0.05), nor to breed (4.94 ± 1.01 and 4.99 ± 0.79 mmol/L in German Shepherd, 5.13 ± 0.84 and 4.99 ± 0.79 mmol/L in Pitt Bull, 5.07 ± 0.94 and 5.07 ± 0.77 mmol/L in Boxer, 5.40 ± 0.59 and 5.48 ± 0.55 mmol/L in Rottweiler and 4.89 ± 0.75 and 4.77 ± 0.59 mmol/L in cross‐bred dogs, respectively, p < 0.05). The present study confirms that human glucometer can be used to measure glucose in dogs with a good accuracy.

Comparison of glucose concentrations in canine whole blood, plasma, and serum measured with a veterinary point-of-care glucometer

Previous studies have determined that, compared to whole blood, serum or plasma used in a portable blood glucometer (PBG) may provide more accurate results. We investigated the accuracy of a veterinary PBG (AlphaTRAK 2; Zoetis) for the measurement of glucose concentrations in serum, plasma, and whole blood compared to plasma glucose concentration measured by a biochemical analyzer. Blood samples from 53 client-owned dogs were collected. Lin concordance correlation coefficient (ρ_c) and Bland-Altman plots were used to determine correlation and agreement between the results obtained for the different sample types. Glucose concentration in whole blood measured by the veterinary PBG was more strongly correlated with the glucose concentration measured by the biochemical analyzer (ρ_c = 0.92) compared to plasma and serum glucose concentrations (ρ_c = 0.59 and 0.57, respectively). The mean differences between the glucose concentrations in whole blood, plasma, and serum measured by the veterinary PBG and the glucose concentration determined by the biochemical analyzer were 1.0, 6.3, and 6.7 mmol/L (18, 113, and 121 mg/dL), respectively. Our findings suggest that, when using this veterinary PBG, the accuracy of a glucose measurement obtained is higher when using whole blood compared to plasma or serum. Use of whole blood allows for more correct assessment and diagnosis, which are necessary for appropriate therapeutic intervention.

Transoperative glycemia in pets: validating old ones, and presenting lip mucosa as new sampling site

The aim of our study was to investigate the viability and validity of blood sampling from the upper lip mucosa in healthy dogs and cats for monitoring transoperative glycemia and compare the results with those obtained from samples taken from previously described blood sampling sites for determination of glycemia using a glucose meter. Blood glucose (BG) levels were determined in samples taken from the upper lip mucosa of 24 dogs and 31 cats undergoing neutering or spaying surgeries. These values were compared to those of samples obtained from other sites previously described for capillary blood glucose monitoring (marginal ear vein, carpal pad in dogs, metacarpal pad in cats) using a glucose meter. Additionally, BG from peripheral venous blood was determined using a glucose meter, and the gold standard enzymatic colorimetric assay. The clinical reliability of BG values taken from lip mucosa and from all the other BG values measured by the glucose meter was evaluated using the error grid analysis modified by Parkes et al (2000). The upper lip mucosa was an easily accessible site for the obtainment of appropriate blood samples, and glucose levels read in these samples correlated positively with glycemic values read in blood samples from all other sites in dogs and cats. All BG made using glucose meters taken from all sites were within the clinically acceptable range when compared with enzymatic colorimetric assay (gold standard), and were analytically accurate according to the error grid (zones A and B). All blood sampling sites described in this work can be used to assess transoperative glycemia. The upper lip mucosa is a viable blood sampling site for precise monitoring of transoperative glycemia in healthy dogs and cats and shows promise for alternative blood glucose monitoring.

Effect of site of sample collection and prandial state on blood glucose concentrations measured with a portable blood glucose meter in healthy dogs

OBJECTIVE

To compare glucose concentrations in peripheral venous and capillary blood samples collected from dogs before and after consumption of a meal and measured with a veterinary-specific portable blood glucose meter (PBGM).

ANIMALS

12 dogs (96 blood samples).

PROCEDURES

A veterinary-specific PBGM was used to measure blood glucose concentrations. Glucose concentrations in capillary blood samples obtained from the carpal pad, medial aspect of a pinna, and oral mucosa were compared with glucose concentrations in blood samples obtained from a lateral saphenous vein. Samples were collected after food was withheld for 12 hours and again 2 hours after consumption of a meal.

RESULTS

Location of capillary blood collection had a significant effect on glucose concentrations measured with the PBGM. Glucose concentration in capillary blood collected from the medial aspect of the pinna did not differ significantly from the glucose concentration in peripheral venous blood samples, whereas glucose concentrations in blood samples collected from the carpal pad and oral mucosa differed significantly from the glucose concentration in peripheral venous blood samples. There was no significant difference between preprandial and postprandial blood glucose concentrations.

CONCLUSIONS AND CLINICAL RELEVANCE

Glucose concentrations in capillary blood collected from the medial aspect of the pinna of dogs better reflected glucose concentrations in venous blood than concentrations measured in capillary blood collected from the carpal pad or oral mucosa.

Cutpoints for screening blood glucose concentrations in healthy senior cats

Objectives The objectives of this study were to determine the reference interval for screening blood glucose in senior cats, to apply this to a population of obese senior cats, to compare screening and fasting blood glucose, to assess whether screening blood glucose is predicted by breed, body weight, body condition score (BCS), behaviour score, fasting blood glucose and/or recent carbohydrate intake and to assess its robustness to changes in methodology. Methods The study included a total of 120 clinically healthy client-owned cats aged 8 years and older of varying breeds and BCSs. Blood glucose was measured at the beginning of the consultation from an ear/paw sample using a portable glucose meter calibrated for cats, and again after physical examination from a jugular sample. Fasting blood glucose was measured after overnight hospitalisation and fasting for 18-24 h. Results The reference interval upper limit for screening blood glucose was 189 mg/dl (10.5 mmol/l). Mean screening blood glucose was greater than mean fasting glucose. Breed, body weight, BCS, behaviour score, fasting blood glucose concentration and amount of carbohydrate consumed 2-24 h before sampling collectively explained only a small proportion of the variability in screening blood glucose. Conclusions and relevance Screening blood glucose measurement represents a simple test, and cats with values from 117-189 mg/dl (6.5-10.5 mmol/l) should be retested several hours later. Cats with initial screening blood glucose >189 mg/dl (10.5 mmol/l), or a second screening blood glucose >116 mg/dl (6.4 mmol/l) several hours after the first, should have fasting glucose and glucose tolerance measured after overnight hospitalisation.

Glucose Detection and Concentration Estimation in Feline Urine Samples with the Bayer Multistix and Purina Glucotest

The Bayer Multistix are commonly used for detection and estimation of feline glucosuria by veterinarians and cat owners. A newer product, the Purina Glucotest, utilizes the same enzymatic technology for detection of glucose, but has been designed for home use as a litter additive that allows interpretation of glucosuria over an 8-h period. The objectives of this study were to assess the sensitivity, specificity, and accuracy of the Glucotest and Multistix, and to assess the 8-h color stability of the Glucotest. Overall, the Glucotest had greater sensitivity and specificity than the Multistix, and more accurately estimated urine glucose concentration if evaluated at least 30 min after exposure to urine. A significant lack of agreement between the results obtained immediately after exposure to urine vs after 30 min and 8 h contradicts the 8-h color stability claim, but the change in urine glucose concentration estimation over time resulted in improved test accuracy at the 30 and 480 min time points.

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.

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.

COMPARAÇÃO ENTRE OS MÉTODOS LABORATORIAL E PORTÁTIL NA ANÁLISE DA GLICEMIA EM FELINOS COM AMOSTRAS DE SANGUE VENOSO CENTRAL E CAPILAR

Objetivou-se comparar a eficácia do método portátil de mensuração glicêmica com o método laboratorial de referência, utilizando-se amostras de sangue venoso central e de sangue capilar de 20 felinos. Considerou-se como valor padrão de referência o obtido pelo método laboratorial a partir de amostra de sangue venoso central. Outros dois valores foram obtidos por glicosímetro portátil, sendo utilizada amostra do mesmo sangue venoso central e outra amostra a partir de sangue capilar. Para os 20 felinos, os resultados glicêmicos verificados pelo método laboratorial tiveram média de 80mg/dL; e os resultados constatados pelo glicosímetro, média de 84,1mg/dL com sangue venoso central e 73,1mg/dL com sangue capilar. As médias glicêmicas obtidas pelo glicosímetro com ambas as amostras de sangue em relação à alcançada pelo método laboratorial resultaram em variações inferiores à máxima instituída (20%) por órgãos reguladores de glicosímetros e por entidade de padronização, bem como a variação entre as médias glicêmicas obtidas pelo aparelho com as distintas amostras de sangue. Na análise comparativa houve diferença significativa entre os métodos (p<0,05). Concluiu-se que o glicosímetro portátil é eficaz para mensuração da glicemia em felinos, tanto a partir de amostras de sangue venoso central como de sangue capilar.

The effects of differing proportions of dietary macronutrients on the digestibility and post-prandial endocrine responses in domestic cats (Felis catus)

The aim of this study was to compare the effects of feeding two diets with different macronutrient proportions (high protein, low carbohydrate and low protein, high carbohydrate) on the digestibility and post-prandial endocrine responses of cats fed at maintenance levels, and to evaluate the effectiveness of the marginal ear vein prick technique for the measurement of blood glucose levels in feline studies. Two diets were fed to 16 adult domestic short-haired cats for a period of three weeks (eight cats per diet). Following a seven-day dietary adaptation period, the apparent macronutrient digestibility of the two diets was determined (days 8-19) using the total faecal collection method. The faeces were freeze dried, ground and analysed for dry matter, crude protein, crude fat and gross energy and then apparent digestibility was calculated. On days 20 and 21, the post-prandial glucose responses of the cats fed a single meal of one of the two diets were measured in serial blood samples collected using the marginal ear vein prick technique.

Results showed that the high protein, low carbohydrate diet had higher (p < 0.05) apparent digestibility of dry matter, crude protein, crude fat and energy, lower (p < 0.01) daily faecal output and smaller fluctuations in blood glucose concentrations. Despite the two groups of cats having similar calorific intakes, the cats fed the high protein diet lost weight over the study period, whereas those fed the high carbohydrate, low protein diet gained weight. The marginal ear vein prick technique proved to be an effective alternative to catheterisation for blood glucose determination. The high protein diet tested in the current study, in addition to being more aligned to the cat's natural carnivorous diet, may be beneficial for weight management and blood glucose control in cats.

ISFM consensus guidelines on the practical management of diabetes mellitus in cats

PRACTICAL RELEVANCE

Diabetes mellitus (DM) is a common endocrinopathy in cats that appears to be increasing in prevalence. The prognosis for affected cats can be good when the disease is well managed, but clinical management presents challenges, both for the veterinary team and for the owner. These ISFM Guidelines have been developed by an independent, international expert panel of clinicians and academics to provide practical advice on the management of routine (uncomplicated) diabetic cats.

CLINICAL CHALLENGES

Although the diagnosis of diabetes is usually straightforward, optimal management can be challenging. Clinical goals should be to limit or eliminate clinical signs of the disease using a treatment regimen suitable for the owner, and to avoid insulin-induced hypoglycaemia or other complications. Optimising bodyweight, feeding an appropriate diet and using a longer acting insulin preparation (eg, protamine zinc insulin, insulin glargine or insulin detemir) are all factors that are likely to result in improved glycaemic control in the majority of cats. There is also some evidence that improved glycaemic control and reversal of glucose toxicity may promote the chances of diabetic remission. Owner considerations and owner involvement are an important aspect of management. Provided adequate support is given, and owners are able to take an active role in monitoring blood glucose concentrations in the home environment, glycaemic control may be improved. Monitoring of other parameters is also vitally important in assessing the response to insulin. Insulin adjustments should always be made cautiously and not too frequently--unless hypoglycaemia is encountered.

EVIDENCE BASE

The Panel has produced these Guidelines after careful review of the existing literature and of the quality of the published studies. They represent a consensus view on practical management of cats with DM based on available clinical data and experience. However, in many areas, substantial data are lacking and there is a need for better studies in the future to help inform and refine recommendations for the clinical management of this common disease.

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.

The clinical utility of two human portable blood glucose meters in canine and feline practice

BACKGROUND

Portable blood glucose meters (PBGMs) are useful for serial measurements of blood glucose and creation of blood glucose curves in veterinary practice. However, it is necessary to validate PBGMs designed for people for veterinary use.

OBJECTIVES

Our objective was to evaluate the accuracy of 2 PBGMs designed for people for use in dogs and cats.

METHODS

The blood glucose levels were determined in blood samples collected from 69 dogs and 26 cats admitted to the Kagoshima University Veterinary Teaching Hospital, using a MEDISAFE [PBGM-T] and an Antsense III [PBGM-H], and a FUJI DRI-CHEM 7000V as reference method. The correlations and agreements among the results were statistically analyzed.

RESULTS

Simple regression analyses revealed a high correlation between values from both PBGMs and the reference method in both dogs and cats. However, Passing-Bablok regression and Bland-Altman analyses revealed that the data from both PBGMs did not show statistical agreement with the reference values. Concordance correlated coefficients were moderate for the PBGM-T and almost perfect for the PBGM-H for canine samples, and were poor for the PBGM-T and substantial for the PBGM-H for feline samples. Hematocrit values significantly affected the results of the PBGM-T, but not the PBGM-H. Error grid analyses revealed that all measurements from both PBGMs would lead to acceptable treatment decisions.

CONCLUSIONS

Our findings suggest that both PBGMs, especially the PBGM-H, would be clinically useful in small animal practice, although there was a bias between each PBGM and the reference method.

Evaluation of sensor sites for continuous glucose monitoring in cats with diabetes mellitus

The continuous glucose monitoring system allows generation of detailed glucose curves via measurement of glucose concentration in interstitial fluid. The conventional site for sensor placement in diabetic cats is the subcutaneous tissue of the lateral chest wall. The aim of this study was to investigate the feasibility and accuracy of sensors placed in the lateral chest wall and in two alternative sites--the dorsal neck and lateral knee fold--of diabetic cats. Initialisation was successful in 15/20 lateral chest wall sensors, 9/10 neck sensors and 3/10 knee fold sensors. Compared with the reference portable blood glucose meter, 0.8% of measurements from lateral chest wall sensors, 0.7% from knee fold sensors and 0% from neck sensors would have resulted in erroneous treatment. This preliminary study suggests that dorsal neck placement may be superior to lateral chest wall and lateral knee fold; however, further investigation with a larger number of cases would be required to confirm this finding.

Chronic "Candidatus Mycoplasma turicensis" infection

"Candidatus Mycoplasma turicensis" infects felids. The pathogenesis of "Candidatus M. turicensis" chronic infection is poorly understood. The goals of the present study were to (1) induce reactivation of the infection in chronic carrier cats by attempted immunosuppression, (2) identify potential tissue sequestration using real-time TaqMan® PCR and (3) monitor the humoral immune response by DnaK enzyme-linked immunosorbent assay (ELISA). Ten specified pathogen-free cats that had ostensibly recovered from experimental "Candidatus M. turicensis" infection were used: five cats (group 1) received high dose methylprednisolone (attempted immunosuppression), while five cats served as untreated controls (group 2). Besides weekly blood samples, tissue samples were collected from bone marrow, kidney, liver and salivary glands at selected time points. The cats in group 1 had significantly lower lymphocyte counts and higher blood glucose levels after methylprednisolone administration than the controls. After methylprednisolone administration one blood and three tissue samples from cats in group 1 tested PCR-positive; before the administration, only one sample was positive. All other samples tested PCR-negative. All cats stayed seropositive; the antibody levels of the cats in group 1 showed a significant transient decrease after methylprednisolone administration. This is the first study to report the presence of "Candidatus M. turicensis" in tissues of chronically infected cats and the persistence of anti-feline hemoplasma antibodies in the absence of detectable bacteremia. Methylprednisolone administration did not lead to a significant reactivation of the infection. Our results enhance the knowledge of "Candidatus M. turicensis" infection pathogenesis and are clinically relevant to the prognosis of hemoplasma-infected cats.

Alternative Sampling Site for Blood Glucose Testing in Cats: Giving the Ears a Rest

Background and study rationale Home monitoring is an important part of the long-term management of diabetic cats. Despite the extensive use of glucometers in this species, up until now only the pinna of the ear has been validated as a testing site. This cross-sectional study investigated the feasibility and validity of sampling from the metacarpal/metatarsal pads in hospitalised cats with various diseases.

Investigations The large pads were compared with the ear as a sampling site in 75 cats. Lancing the pads was tolerated very well. If the initial drop of blood was too small, an adequate volume of blood was almost always achieved by squeezing the pads. No significant differences were observed in first-attempt success rate or glucose values between the two sites. Due to the inability to obtain an adequate volume of blood or struggling, no measurement was possible in four cats.

Practical relevance While further work is necessary to assess the utility of this technique, especially in the home environment, the results indicate that the metacarpal pads, in particular, may offer a viable alternative testing site for the measurement of blood glucose concentrations, especially if ear sampling fails.

Evaluation of six portable blood glucose meters for measuring blood glucose concentration in dogs

OBJECTIVE

To evaluate accuracy of 6 portable blood glucose meters (PBGMs) by comparing results of these meters with results obtained with a reference chemistry analyzer.

DESIGN

Evaluation study.

ANIMALS

49 dogs (158 blood samples). Procedures-Venous blood samples were tested with the 6 PBGMs, and results were compared with results of a commercially available analyzer that used a reference method based on the hexokinase reaction.

RESULTS

Plasma glucose concentrations obtained with the reference analyzer ranged from 41 to 639 mg/dL. There were significant correlations between blood glucose concentrations obtained with the 6 PBGMs and plasma glucose concentrations obtained with the reference analyzer (r > or = 0.96). However, for all 6 PBGMs, results differed from results for the reference analyzer, with the difference increasing as plasma glucose concentration increased. Significant differences in bias were found among meters. For 142 samples classified as hypoglycemic, euglycemic, or hyperglycemic on the basis of results of the reference analyzer, the percentage of samples that were misclassified on the basis of results of the PBGMs ranged from 2.1% to 38.7%.

CONCLUSIONS AND CLINICAL RELEVANCE

Results of the present study suggested that there were substantial differences in the accuracy of currently available PBGMs when used to determine blood glucose concentration in dogs.

Diabetes in people, cats, and dogs: biomedicine and manifold ontologies

If people express salient beliefs and values in caring for pets then it is worth considering that dogs and housecats are routinely treated using the biomedical armamentarium. To investigate animal-human connections in the treatment of dogs and housecats for diabetes, we conducted ethnographic interviews in Canada with 12 pet owners and six health professionals in conjunction with a review of documentation on diabetes in cats, dogs, and people. Treating dogs and housecats for diabetes, we conclude, pivots on recognition of these animals as sentient selves. At the same time, treating diabetes in dogs and housecats helps to produce a named disease as a physical thing. In treating a housecat or a dog for diabetes, pet owners breach one of the foundational distinctions of Western science: human and nonhuman bodies exhibit continuity in terms of physicality, but a fundamental discontinuity exists when it comes to interiority.

Day-to-day variability of blood glucose concentration curves generated at home in cats with diabetes mellitus

OBJECTIVE

To evaluate day-to-day variability in blood glucose curves (BGCs) generated at home and at the clinic for cats with diabetes mellitus.

DESIGN

Prospective study.

ANIMALS

7 cats with diabetes mellitus. Procedures-BGCs generated at home on 2 consecutive days and within 1 week at the clinic were obtained twice. On each occasion, insulin dose, amount of food, and type of food were consistent for all 3 BGCs. Results of curves generated at home were compared with each other and with the corresponding clinic curve.

RESULTS

Differences between blood glucose concentration determined after food was withheld (fasting), nadir concentration, time to nadir concentration, maximum concentration, and mean concentration during 12 hours had high coefficients of variation, as did the difference between fasting blood glucose and nadir concentrations and area under the curve of home curves. Differences between home curve variables were not smaller than those between home and clinic curves, indicating large day-to-day variability in both home and clinic curves. Evaluation of the paired home curves led to the same theoretical recommendation for adjustment of insulin dose on 6 of 14 occasions, and evaluation of home and clinic curves resulted in the same recommendation on 14 of 28 occasions. Four of the 6 paired home curves in cats with good glycemic control and 2 of the 8 paired home curves in cats with poor glycemic control led to the same recommendation.

CONCLUSIONS AND CLINICAL RELEVANCE

Considerable day-to-day variability was detected in BGCs generated at home. Cats with good glycemic control may have more reproducible curves generated during blood collection at home than cats with poorer control.

Update on Drugs Used to Treat Endocrine Diseases in Small Animals

Drug therapy for the endocrine system is implemented to replace a hormone deficiency or to prevent or reduce the formation or effects of excess hormone. Treatment of endocrine disorders covers diseases of the pituitary, adrenal, parathyroid, and thyroid glands as well as the endocrine pancreas. This article focuses on new therapies currently available for specific diseases. Administration of trilostane for treatment of hyperadrenocorticism and use of insulin glargine, protamine zinc insulin (PZI), and porcine Lente insulin for diabetes mellitus are discussed. In addition, transdermal methimazole therapy for treatment of feline hyperthyroidism and administration of progestins for pituitary dwarfism are considered.

Evaluation of a continuous glucose monitoring system for use in veterinary medicine

BACKGROUND

With the emergence of continuous glucose monitoring systems being used to provide a detailed glucose picture in humans, a commercially available system (CGMS(R), Medtronic Minimed, Northridge, CA) was examined for use in veterinary species.

METHODS

Adult, clinically normal horses (n = 7), cats (n = 3), dogs (n = 4), and cows (n = 5) were studied. Cats (n = 4), dogs (n = 5), and one horse with diabetes were included in the study. Several of the normal horses, including the horse with diabetes, and one cow were subjected to an intravenous glucose tolerance test. The CGMS was attached to each animal, and the recorded interstitial glucose concentrations were compared with whole blood glucose concentrations as determined by a point-of-care glucose meter. Events such as insulin administration, feeding, travel, or administration of intravenous glucose were all noted and compared with results from the CGMS.

RESULTS

There was a positive correlation between interstitial and whole blood glucose concentrations for all the clinically normal species, those with diabetes mellitus, and those receiving intravenous glucose. Events such as feeding, glucose or insulin administration, and transport to the clinic were noted by the owner or clinician and could be identified on the graph and correlated with time of occurrence.

CONCLUSIONS

Our data indicate that the use of the CGMS is valid for use in the species examined. Use of this system alleviated the need for multiple blood samples and the stress associated with obtaining those samples. This system may provide greater monitoring capabilities in patients with diabetes and promote the diagnostic and research potential of serial glucose monitoring in veterinary species.

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 for use in dogs, cats, and horses

OBJECTIVE

To evaluate a continuous glucose monitoring system (CGMS) for use in dogs, cats, and horses.

DESIGN

Prospective clinical study. Animals-7 horses, 3 cats, and 4 dogs that were clinically normal and 1 horse, 2 cats, and 3 dogs with diabetes mellitus.

PROCEDURE

Interstitial glucose concentrations were monitored and recorded every 5 minutes by use of a CGMS. Interstitial glucose concentrations were compared with whole blood glucose concentrations as determined by a point-of-care glucose meter. Interstitial glucose concentrations were also monitored in 2 clinically normal horses after oral and i.v. administration of glucose.

RESULTS

There was a positive correlation between interstitial and whole blood glucose concentrations for clinically normal dogs, cats, and horses and those with diabetes mellitus. Events such as feeding, glucose or insulin administration, restraint, and transport to the clinic were recorded by the owner or clinician and could be identified on the graph and associated with time of occurrence.

CONCLUSIONS AND CLINICAL RELEVANCE

Our data indicate that use of CGMS is valid for dogs, cats, and horses. This system alleviated the need for multiple blood samples and the stress associated with obtaining those samples. Because hospitalization was not required, information obtained from the CGMS provided a more accurate assessment of the animal's glucose concentrations for an extended period, compared with measurement of blood glucose concentrations. Use of the CGMS will promote the diagnostic and research potential of serial glucose monitoring.