Serum Fructosamine Concentration as an Index of Glycemia in Cats With Diabetes Mellitus and Stress Hyperglycemia

The purpose of this study was to evaluate fructosamine concentrations in clinically healthy cats, sick cats with stress hyperglycemia, and untreated diabetic cats to determine the usefulness of this test in diagnosing diabetes mellitus in cats, and in differentiating the disease from stress-induced hyperglycemia. In addition, we evaluated if the degree of glycemic control in cats treated for diabetes influenced their serum fructosamine concentrations. In the 14 sick cats with stress hyperglycemia, the median serum fructosamine concentration (269 μmol/L) was not significantly different from the median value in the 26 clinically normal cats (252 μmol/L). Two of the 14 cats with stress hyperglycemia (14.3%) had serum fructosamine concentrations above the upper limit of the reference range (175 to 400 μmol/U; on the basis of these results, the test specificity was calculated as 0.86. In 30 cats with untreated diabetes mellitus, the median serum fructosamine concentration was 624 μmol/L, markedly higher than the value in either the normal cats or the cats with stress hyperglycemia. All but 2 of the 30 untreated diabetic cats (6.7%) had serum fructosamine concentration above the upper limit of the reference range; on the basis of these results, the sensitivity of serum fructosamine concentration as a diagnostic test for diabetes mellitus was 0.93. When 30 diabetic cats receiving treatment were divided into 3 groups according to their response to treatment (ie, poor, fair, and good), the 16 cats that had a good response to treatment had significantly lower serum concentrations of both glucose and fructosamine compared with cats that had either a fair or poor response to treatment. A significant correlation (r_s= .70, n = 100, P < .001) was found between serum concentrations of glucose and fructosamine. Results of this study indicate that quantification of serum fructosamine concentration is a meaningful test for the diagnosis of diabetes, for differentiating diabetes from stress hyperglycemia; and for monitoring the metabolic control in treated diabetic cats.     

Fructosamine concentrations in hyperglycemic cats.

The aims of this study were 1) to establish a reference range for fructosamine in cats using a commercial fructosamine kit; 2) to demonstrate that the fructosamine concentration is not increased by transient hyperglycemia of 90 min duration, simulating hyperglycemia of acute stress; and 3) to determine what percentage of blood samples submitted to a commercial laboratory from 95 sick cats had evidence of persistent hyperglycemia based on an elevated fructosamine concentration. Reference intervals for the serum fructosamine concentration were established in healthy, normoglycemic cats using a second generation kit designed for the measurement of the fructosamine concentration in humans. Transient hyperglycemia of 90 min duration was induced by IV glucose injection in healthy cats. Multisourced blood samples that were submitted to a commercial veterinary laboratory either as fluoride oxalated plasma or serum were used to determine the percentage of hyperglycemic cats having persistent hyperglycemia. The reference interval for the serum fructosamine concentration was 249 to 406 mumol/L. Transient hyperglycemia of 90 min duration did not increase the fructosamine concentration and there was no correlation between fructosamine and blood glucose. In contrast, the fructosamine concentration was correlated with the glucose concentration in sick hyper- and normoglycemic cats. It is concluded that the fructosamine concentration is a useful marker for the detection of persistent hyperglycemia and its differentiation from transient stress hyperglycemia. Fructosamine determinations should be considered when blood glucose is 12 to 20 mmol/L and only a single blood sample is available for analysis.     

Serum Fructosamine: A Reference Interval for a Heterogeneous Canine Population

Eighty-nine healthy dogs (44 males, 45 females) of different breeds, 1-12 years of age, living under varied feeding and environmental conditions, were sampled to evaluate a reference interval for serum fructosamine using a nitroblue tetrazolium photocolorimetric method. The analytical assay was evaluated by calculation of within-run and between-day variations. The results were approximately normally distributed and the calculated reference interval was 192.6-357.4 µmol/L (mean 275.0 µmol/L, standard deviation 41.2 µmol/L). No significant differences attributable to sex or age were observed. This reference interval is wider than those previously reported in less heterogeneous groups of dogs and in those from other geographical zones. The fructosamine values in serum from 3 diabetic dogs all exceeded the upper limit of the reference interval.     

Reference interval and critical difference for canine serum fructosamine concentration

The purposes of the study were to obtain a reference interval and to calculate the critical difference between two analytical results for canine serum fructosamine concentration. To obtain a reference interval, the serum fructosamine concentration was measured in blood samples from 29 adult dogs after a 15-h fasting period. To calculate the critical difference, blood samples from 20 apparently clinically healthy dogs were collected once weekly for five consecutive weeks, and the total variance of the analytical results was divided into the component of variance between dogs (S _inter ² ), the component of variance for weeks within dogs (S _intra ² ) and the component of variance for measurements (S _anal ² ), using nested analysis of variance. The critical difference was then calculated fromS _intra ² andS _anal ² .The main conclusions are in summary: The reference interval for canine serum fructosamine concentration is 258.6–343.8 µmol/L, and the critical difference between two consecutive measurements on a week-to-week basis is 32.4 µmol/L. The critical difference may be used as a guideline to indicate potentially important changes in the serum fructosamine concentration, though the analytical results should not be assessed by the critical differences alone, but should also be compared to the corresponding reference intervals.     

Diagnostic significance of serum glycated albumin in diabetic dogs

Measurements of serum fructosamine, glycated hemoglobin, and glycated albumin (GA) are increasingly used to complement serum glucose concentration for better management of diabetes mellitus. Fructosamine tests are currently not performed in veterinary medicine in Japan. As such, the measurement of GA may serve as a replacement test. Therefore, in the current study, serum GA and fructosamine were evaluated for a positive correlation in dogs, and, depending on the correlation, a reference range of GA percentage would also be determined from healthy control dogs. The degree of glycemic control in diabetic dogs was determined by fructosamine concentration. A positive correlation between GA and fructosamine was observed with both normal and diabetic animals. In addition, the reference interval of serum GA percentage in control dogs was determined to be 11.4-11.9% (95% confidence interval). Interestingly, no significant difference in serum GA percentages was observed between samples from diabetic dogs with excellent glycemic control and control dogs. However, good, fair, and poor glycemic control diabetic dogs resulted in a significant increase in serum GA percentages in comparison with control dogs. These results suggest that serum GA may be a useful diagnostic indicator, substituting for fructosamine, to monitor glycemic control in diabetic dogs.     

Retrospective evaluation of the effect of trilostane on insulin requirement and fructosamine concentration in eight diabetic dogs with hyperadrenocorticism

Objectives : To describe the effect of trilostane on insulin requirements and serum fructosamine in dogs with diabetes mellitus (DM) and hyperadrenocorticism (HAC). Methods : Observational retrospective study of eight dogs. Results : Median fructosamine concentration at presentation was 401 μmol/L (range 244 to 554 μmol/L). Median insulin dose at presentation was 1·1 IU/kg/dose (0·4 to 2·1 IU/kg/dose) administered twice daily in five animals and once in three. Four dogs had their insulin dose prospectively reduced at the start of trilostane therapy. The HAC was controlled within 28 days in seven dogs. The remaining case was controlled by 17 weeks. Two dogs died within 40 days of starting trilostane. The median fructosamine concentration was 438 μmol/L (range 325 to 600 μmol/L) after stabilisation of the HAC. One case had a consistent reduction in serum fructosamine concentration over the first four months. The median insulin dose after stabilisation of HAC was 1·5 IU/kg dose (range 0·25 to 3·0 IU/kg/dose). Insulin requirements were reduced in two cases after treatment with trilostane. Four dogs required increased insulin doses. Clinical Significance : Insulin requirements and fructosamine concentrations do not consistently reduce during trilostane treatment for HAC. Prospective studies are required to provide recommendations regarding reductions in insulin doses with trilostane treatment.     

Relation of fructosamine to serum protein, albumin, and glucose concentrations in healthy and diabetic dogs.

The relation of the glycated serum protein, fructosamine, to serum protein, albumin, and glucose concentrations was examined in healthy dogs, dogs with hypo- or hyperproteinemia, and diabetic dogs. Fructosamine was determined by use of an adaptation of an automated kit method. The reference range for fructosamine in a composite group of control dogs was found to be 1.7 to 3.38 mmol/L (mean +/- SD, 2.54 +/- 0.42 mmol/L). Fructosamine was not correlated to serum total protein, but was highly correlated to albumin in dogs with hypoalbuminemia. To normalize the data with respect to albumin, it is suggested that the lower limit of the reference range for albumin concentration (2.5 g/dl) be used for adjustment of fructosamine concentration and only in hypoalbuminemic dogs. In 6 hyperglycemic diabetic dogs, fructosamine concentration was well above the reference range. It is concluded that although fructosamine may be a potentially useful guide to assess the average blood glucose concentration over the preceding few days in dogs, further study is required to establish its value as a guide to glucose control in diabetic dogs.     

Coagulation values in normal ferrets (Mustela putorius furo) using selected methods and reagents

Background: Accurate determination of commonly measured coagulation values would be useful in the diagnosis and management of coagulopathies in domestic ferrets (Mustela putorius furo). We are unaware of reports of coagulation times in this species. Objectives: The purpose of this study was to determine reference values for prothrombin time (PT), activated partial thromboplastin time (PTT), fibrinogen concentration, and antithrombin (AT) activity in ferrets using selected methods and reagents. Methods: Blood samples obtained from 18 clinically healthy ferrets were anticoagulated with 0.129 M sodium citrate in a ratio of 9 parts blood to 1 part anticoagulant. Plasma was collected and stored at -70 degrees C until analysis. PT and PTT were measured with a fibrometer and with an ACL 3000 automated system. PTT was measured with and without the addition of ellagic acid. Fibrinogen was assayed by a turbidimetric method. AT activity was determined using a chromogenic assay and pooled ferret plasma (100% activity). Differences in methods and reagents were evaluated using paired t tests. Results: PT was significantly longer using the fibrometer (12.3+/-0.3, 11.6-12.7 seconds) compared with the ACL (10.9+/-0.3, 10.6-11.6 seconds) (P<.01). PTT was not significantly different with the fibrometer (18.7+/-0.9, 17.5-21.1 seconds) vs the ACL (18.1+/-1.1, 16.5-20.5 seconds), but was significantly longer on both analyzers when ellagic acid was added (fibrometer 20.4+/-0.8, 18.9-22.3 seconds; ACL 20.0+/-1.0, 18.6-22.1 seconds) (P<.01). Fibrinogen concentration was 107.4+/-19.8 mg/dL (90.0-163.5 mg/dL), and AT activity was 96%+/-12.7% (69.3-115.3%). Conclusion: These coagulation results for healthy ferrets will be useful in the evaluation of ferrets with coagulopathies, provided similar reagents and methods are used.     

Urinary glucocorticoid excretion in the diagnosis of hyperadrenocorticism in ferrets

Hyperadrenocorticism in ferrets is usually associated with unaltered plasma concentrations of cortisol and adrenocorticotropic hormone (ACTH), although the urinary corticoid/creatinine ratio (UCCR) is commonly elevated. In this study the urinary glucocorticoid excretion was investigated in healthy ferrets and in ferrets with hyperadrenocorticism under different circumstances. In healthy ferrets and in one ferret with hyperadrenocorticism, approximately 10% of plasma cortisol and its metabolites was excreted in the urine. High-performance liquid chromatography (HPLC) revealed one third of the urinary corticoids to be unconjugated cortisol; the other peaks mainly represented cortisol conjugates and metabolites. In 21 healthy sexually intact ferrets, the UCCR started to increase by the end of March and declined to initial values halfway the breeding season (June). In healthy neutered ferrets there was no significant seasonal influence on the UCCR. In two neutered ferrets with hyperadrenocorticism the UCCR was increased, primarily during the breeding season. In 27 of 31 privately owned ferrets with hyperadrenocorticism, the UCCR was higher than the upper limit of the reference range (2.1 x 10(-6)). In 12 of 14 healthy neutered ferrets dexamethasone administration decreased the UCCR by more than 50%, whereas in only 1 of the 28 hyperadrenocorticoid ferrets did the UCCR decrease by more than 50%. We conclude that the UCCR in ferrets primarily reflects cortisol excretion. In healthy sexually intact ferrets and in ferrets with hyperadrenocorticism the UCCR increases during the breeding season. The increased UCCR in hyperadrenocorticoid ferrets is resistant to suppression by dexamethasone, indicating ACTH-independent cortisol production.     

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

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

Ciclosporin A therapy is associated with disturbances in glucose metabolism in dogs with atopic dermatitis

The effect of ciclosporin A (CsA) on glucose homeostasis was investigated in 16 dogs with atopic dermatitis by determining plasma glucose, serum fructosamine and insulin concentrations, and serial insulin and glucose concentrations following a glucagon stimulation test, before and 6 weeks after CsA therapy at 5 mg/kg once daily. All dogs completed the study. Following CsA treatment, the median serum fructosamine concentrations were significantly higher (pretreatment 227.5 μmol/L; post-treatment 246.5 μmol/L; P = 0.001; reference range 162-310 μmol/L). Based on analyses of the areas under concentration-time curves (AUC) pre- and post-CsA treatment, plasma glucose concentrations were significantly higher (AUC without baseline correction 31.0 mmol/L/min greater; P = 0.021) and serum insulin concentrations were significantly lower (AUC without baseline correction 217.1 μIU/mL/min lower; P = 0.044) following CsA treatment. Peak glucose concentrations after glucagon stimulation test were significantly higher following CsA treatment (10.75 versus 12.05 mmol/L; P = 0.021), but there was no significant difference in peak serum insulin (52.0 versus 35.0 μIU/mL; P = 0.052). There was a negative correlation between baseline uncorrected insulin AUC and trough serum log CsA concentrations (r = -0.70, P = 0.005). The administration of CsA to dogs with atopic dermatitis leads to disturbances in glucose homeostasis. The clinical significance of this is unclear, but it should be taken into account when considering CsA treatment in dogs that already have such impairments.     

Composition of cerebrospinal fluid in clinically normal adult ferrets

OBJECTIVE: To determine the protein and cellular composition of CSF in healthy adult ferrets. ANIMALS: 42 clinically normal adult ferrets. PROCEDURE: CSF samples were collected from the cerebellomedullary cistern of anesthetized ferrets by use of disposable 25-gauge, 1.6-cm-long hypodermic needles. Samples were processed within 20 minutes after collection. The number of WBCs and RBCs per microliter of CSF was counted by use of a hemacytometer. The total protein concentration was determined by use of an automated chemistry analyzer. RESULTS: Total WBC counts (range, 0 to 8 cells/microL; mean, 1.59 cells/microL) in CSF of ferrets were similar to reference range values obtained for CSF from other species. Twenty-seven CSF samples had <100 RBCs/microL (mean, 20.3 RBCs/microL). A small but significant effect of blood contamination on WBC counts was found between the 27 CSF samples with <100 RBCs/microL and the remaining samples. Protein concentrations in CSF of ferrets (range, 28.0 to 68.0 mg/dL; mean, 31.4 mg/dL) were higher than has been reported for the CSF of dogs and cats. A significant effect of blood contamination on the CSF protein concentration was not found. CONCLUSION AND CLINICAL RELEVANCE: We have established reference range values for WBC counts and protein concentrations in CSF from healthy adult ferrets that may be useful in the clinical investigation of CNS disease. Results of our study indicate that the WBC count is significantly affected by blood contamination of the CSF sample.     

Increased plasma fructosamine concentrations in laminitic horses

Reasons for performing study: The use of plasma fructosamine concentration ([fructosamine]) as a marker of abnormal glucose homeostasis in laminitic horses has not been investigated. Hypothesis: Plasma fructosamine concentration may be higher amongst laminitic horses than normal horses; this might relate to underlying insulin resistance. Objectives: 1) To compare [fructosamine] between laminitic and normal horses. 2) To investigate associations between [fructosamine] at presentation in laminitic horses with a) single sample markers of insulin resistance and b) outcome. Methods: Plasma fructosamine concentration, fasting serum insulin concentration (insulin) and fasting plasma glucose concentration (glucose) were measured in 30 horses that presented with laminitis. Clinical details and follow‐up data were recorded. Plasma fructosamine concentration was also measured in 19 nonlaminitic control horses. Results: Laminitic horses had significantly higher mean [fructosamine] than normal horses (P<0.001). Thirteen of 30 laminitic horses had fasting hyperinsulinaemia, 2/30 had fasting hyperglycaemia. Statistically significant univariable correlations were identified between [fructosamine] and [glucose], [insulin] and the proxies RISQI and MIRG. Trends for association between [fructosamine] and negative outcome did not reach statistical significance. Conclusions and potential relevance: Increased mean [fructosamine] in laminitic horses may represent abnormal glycaemic control and [fructosamine] may become a clinically useful marker.     

Reference ranges for laboratory parameters in ferrets

The purpose of this study was to establish reference ranges (robust methods) for 51 laboratory parameters in ferrets for use in private practice. Current literature concerning reference values in ferrets is often based on small patient numbers, methods of blood sampling not suitable for practice, and outdated laboratory methods. Blood was collected from the V saphena lateralis of 111 clinically healthy ferrets (age 11 weeks to 9 years; 61 male, 50 female). Age, sex (male or female) and fasting status were taken into consideration. Parameters evaluated included haematological parameters (packed?cell volume, haemoglobin, erythrocytes, erythrocyte indices, white blood cells, differential blood counts, platelets) (Cell-Dyn3500R; microscopical differential blood count), serum parameters (alanine aminotransferase, alkaline phosphatase, aspartate aminotransaminase, glutamate dehydrogenase, γ-glutamyltranspeptidase, lactate dehydrogenase, creatine kinase, α-amylase, lipase, cholinesterase, glucose, fructosamine, total protein, cholesterol, triglycerides, serum bile acids, bilirubin, urea, creatinine), serum electrolyte levels (calcium, phosphorus, magnesium, sodium, potassium, chloride, iron) (Hitachi 911), and serum hormone concentrations (thyroxine, cortisol, oestradiol, progesterone) (Elecsys 1010). Results differing from reference ranges reported in current literature were attributed in most cases to the use of other blood sampling methods and laboratory equipment.     

Serum fructosamine concentration in cats with overt hyperthyroidism.

OBJECTIVE: To determine the effect of hyperthyroidism on serum fructosamine concentration in cats. DESIGN: Cohort study. ANIMALS: 22 cats with overt hyperthyroidism. PROCEDURE: Hyperthyroidism was diagnosed on the basis of clinical signs, detection of a palpable thyroid gland, and high total serum thyroxine (T4) concentrations. Hyperthyroid cats with abnormal serum albumin, total protein, and glucose concentrations were excluded from the study. Samples for determination of serum fructosamine concentration were obtained prior to initiating treatment. Results were compared with fructosamine concentrations in healthy cats, cats in which diabetes had recently been diagnosed, and cats with hypoproteinemia. In 6 cats, follow-up measurements were obtained 2 and 6 weeks after initiating treatment with carbimazole. RESULTS: Serum fructosamine concentrations ranged from 154 to 267 mumol/L (median, 198 mumol/L) and were significantly lower than values in healthy cats. Eleven (50%) of the hyperthyroid cats had serum fructosamine concentrations less than the reference range. Serum fructosamine concentrations in hyperthyroid, normoproteinemic cats did not differ from values in hypoproteinemic cats. During treatment, an increase in serum fructosamine concentration was detected. CONCLUSIONS AND CLINICAL RELEVANCE: In hyperthyroid cats, concentration of serum fructosamine may be low because of accelerated protein turnover, independent of blood glucose concentration. Serum fructosamine concentrations should not be evaluated in cats with overt hyperthyroidism and diabetes mellitus. Additionally, concentration of serum fructosamine in hyperthyroid cats should not be used to differentiate between diabetes mellitus and transitory stress-related hyperglycemia.     

Spurious hypercreatininemia: 28 neonatal foals (2000–2008)

Objectives – To (1) determine the occurrence of spurious hypercreatininemia in a population of hospitalized foals <2 days old, (2) assess the resolution of the hypercreatininemia, and (3) determine its association with survival in these foals. Design – Retrospective case series. Setting – 2 Referral hospitals. Animals – Foals <2 days old with an admission creatinine >442 μmol/L (>5.0 mg/dL) from 2 referral hospitals. Interventions – None. Measurements and Main Results – The medical records of 33 foals were reviewed. Twenty‐eight had spurious hypercreatininemia and 5 had acute renal failure. Admission creatinine was not significantly different between the 2 groups (mean [standard deviation]). The creatinine was 1,202 μmol/L (663 μmol/L) (13.6 mg/dL [7.5 mg/dL]) versus 1,185 μmol/L (787 μmol/L) (13.4 mg/dL [8.9 mg/d]) (P=0.96) in each group, respectively, though BUN at the time of hospital admission was significantly higher for acute renal failure foals (P=0.009). In the spurious group, serum creatinine at admission decreased to 504 μmol/L (380 μmol/L) (5.7 mg/dL [4.3 mg/dL]) by 24 hours, and to 159 μmol/L (80 μmol/L) (1.8 mg/dL [0.9 mg/dL]) at 48 hours, and to 115 μmol/L (44 μmol/L) (1.3 mg/dL [0.5 mg/dL]) at 72 hours. Twenty‐three of 28 foals with spurious hypercreatininemia survived to hospital discharge and there was no difference in mean admission creatinine between survivors (1176 μmol/L [628 μmol/L]) (13.3 mg/dL [7.1 mg/dL]) and nonsurvivors (1308 μmol/L [857 μmol/L]) (14.8 mg/dL [9.7 mg/dL]) (P=0.67). Twenty of 28 foals had clinical signs suggestive of neonatal encephalopathy. Conclusion – Creatinine decreased by >50% within the initial 24 hours of standard neonatal therapy and was within the reference interval in all but 1 foal within 72 hours of hospitalization. The diagnosis of neonatal encephalopathy was common in these foals.     

The Long-term Biological Variability of Fasting Plasma Glucose and Serum Fructosamine in Healthy Beagle Dogs

The aim of this study was to estimate the long-term (month-to-month) between-dog, within-dog and analytical components of variance for fasting plasma glucose and serum fructosamine in healthy dogs to assess the usefulness of a single measurement of these analytes in a single dog.Fasting plasma glucose and serum fructosamine were measured in blood samples collected every month for 9 months from 23 clinically healthy dogs, and the results were subjected to nested analysis of variance. The between-dog variation, the within-dog variation, and the analytical variation were 3.8%, 9.5% and 3.7%, respectively, for plasma glucose and 4.2%, 11.1% and 2.8%, respectively, for serum fructosamine.The maximum allowable analytical imprecision, analytical inaccuracy and difference between analytical methods were 4.8%, 2.6% and 3.2%, respectively, for plasma glucose and 5.6%, 3.0% and 3.7%, respectively, for serum fructosamine.The index of individuality, 2.7 for both analytes, indicated that the test results from single dogs can be compared usefully to the corresponding population-based reference intervals.The number of samples required to estimate the true individual mean value ±5% for a single dog was 16 for fasting plasma glucose and 20 for serum fructosamine.The one- and two-sided critical differences expressing the difference needed for two serial results from the same dog to be significantly different at a 5% level was 24% and 28%, respectively, for plasma glucose and 27% and 32%, respectively, for serum fructosamine.     

I plasma concentrations of adrenocorticotrophic hormone and alpha-melanocyte-stimulating hormone in ferrets (Mustela putorius furo) with hyperadrenocorticism

OBJECTIVE: To determine plasma concentrations of adrenocorticotrophic hormone (ACTH) and alpha-melanocyte stimulating-hormone (alpha-MSH) in healthy ferrets and ferrets with hyperadrenocorticism. ANIMALS: 16 healthy, neutered, privately owned ferrets, 28 healthy laboratory ferrets (21 sexually intact and 7 neutered), and 28 ferrets with hyperadrenocorticism. PROCEDURES: Healthy ferrets were used for determination of reference plasma concentrations of ACTH and a-MSH. Diagnosis of hyperadrenocorticism was made on the basis of history, clinical signs, urinary corticoid-to-creatinine ratios, ultrasonography of the adrenal glands, and macroscopic or microscopic evaluation of the adrenal glands. Blood samples were collected during isoflurane anesthesia. Plasma concentrations of ACTH and alpha-MSH were measured by radioimmunoassay. RESULTS: Plasma concentrations of ACTH in 23 healthy neutered ferrets during the breeding season ranged from 4 to 145 ng/L (median, 50 ng/L). Plasma concentrations of alpha-MSH in 44 healthy neutered or sexually intact ferrets during the breeding season ranged from < 5 to 617 ng/L (median, 37 ng/L). Reference values (the central 95% of the values) for ACTH and alpha-MSH were 13 to 100 ng/L and 8 to 180 ng/L, respectively. Plasma concentrations of ACTH and alpha-MSH in ferrets with hyperadrenocorticism ranged from 1 to 265 ng/L (median, 45 ng/L) and 10 to 148 ng/L (median, 46 ng/L), respectively. These values were not significantly different from those of healthy ferrets. Plasma ACTH concentrations of sexually intact female ferrets in estrus were significantly higher than those of neutered females. CONCLUSIONS AND CLINICAL RELEVANCE: Ferrets with hyperadrenocorticism did not have detectable abnormalities in plasma concentrations of ACTH or alpha-MSH. The findings suggest that hyperadrenocorticism in ferrets is an ACTH and alpha-MSH-independent condition.     

Changes in blood glucose concentration are associated with relatively rapid changes in circulating fructosamine concentrations in cats

The aim of the study was to determine the time required for plasma fructosamine concentration to increase after the onset of hyperglycaemia and decrease after resolution of hyperglycaemia. Healthy cats (n=14) were infused to maintain either moderate hyperglycaemia (n=5) (actual mean glucose 17 mmol/l) or marked hyperglycaemia (n=9) (actual 29 mmol/l) for 42 days. Fructosamine exceeded the upper limit of the reference range (331 micromol/l) after 3-5 days of marked hyperglycaemia, took 20 days to plateau and, after cessation of infusion, took 5 days to return to baseline. Fructosamine concentration for moderate hyperglycaemia took longer to exceed the reference range (7 days, range 4-14 days), and fewer days to plateau (8 days) and return to baseline (1 day). In cats with moderate hyperglycaemia, fructosamine concentration mostly fluctuated under the upper limit of the reference range. The range of fructosamine concentrations associated with a given glucose concentration was wide. The critical difference for fructosamine was 33 micromol/l.     

Serum cobalamin, urine methylmalonic acid, and plasma total homocysteine concentrations in Border Collies and dogs of other breeds

Objective-To determine reference ranges for serum cobalamin (Cbl), urine methylmalonic acid (uMMA), and plasma total homocysteine (tHcys) concentrations and to compare values for healthy control dogs with values for Border Collies (BCs), a breed in which hereditary cobalamin deficiency has been identified. Animals-113 BCs, 35 healthy control dogs fed a typical diet, and 12 healthy dogs fed a bone and raw food diet exclusively. Procedures-Urine and blood samples were obtained from each dog and Cbl, uMMA, and tHcys concentrations were determined. Results-Reference ranges for Cbl (261 to 1,001 ng/L), uMMA (0 to 4.2 mmol/mol of creatinine), and tHcys (4.3 to 18.4 μmol/L) concentrations were determined. Four BCs had a Cbl concentration lower than the assay detection limit (150 ng/L); median uMMA and tHcys concentrations in these dogs were 4,064 mmol/mol of creatinine and 51.5 μmol/L, respectively. Clinical abnormalities included stunted growth, lethargy, anemia, and proteinuria. Abnormalities improved after administration of cobalamin. Of the 109 healthy BCs with Cbl and tHcys concentrations within reference ranges, 41 (37.6%) had a high uMMA concentration (range, 5 to 360 mmol/mol). Results for dogs fed raw food were similar to those for control dogs. Conclusions and Clinical Relevance-Hereditary cobalamin deficiency is a rare disease with various clinical signs. The finding of methylmalonic aciduria in healthy eucobalaminemic BCs and BCs with clinical signs of Cbl deficiency was surprising and indicated these dogs may have defects in intracellular processing of Cbl or intestinal Cbl malabsorption, respectively. Studies investigating Cbl absorption and metabolic pathways are warranted.