The daytime feeding frequency affects appetite-regulating hormones, amino acids, physical activity, and respiratory quotient, but not energy expenditure, in adult cats fed regimens for 21 days.

The effects of feeding frequency on postprandial response of circulating appetite-regulating hormones, insulin, glucose and amino acids, and on physical activity, energy expenditure, and respiratory quotient were studied in healthy adult cats. Two experiments were designed as a 2 x 3 replicated incomplete Latin square design. Eight cats, with an average body weight (BW) of 4.34 kg ± 0.04 and body condition score (BCS) of 5.4 ± 1.4 (9 point scale), were fed isocaloric amounts of a commercial adult maintenance canned cat food either once (0800 h) or four times daily (0800 h, 1130 h, 1500 h, 1830 h). Study 1 consisted of three 21-d periods. On day 14, two fasted and 11 postprandial blood samples were collected over 24 hours to measure plasma concentrations of ghrelin, GLP-1, GIP, leptin, PYY, insulin and amino acids, and whole blood glucose. Physical activity was monitored from day 15 to 21 of each period. In Study 2 indirect calorimetry was performed on the last day of each period. Body weight was measured weekly and feed intake recorded daily in both experiments. No effect of feeding regimen on BW was detected. Cats eating four times daily had lesser plasma concentrations of GIP and GLP-1 (P<0.05) and tended to have lesser plasma PYY concentrations (P<0.1). Plasma leptin and whole blood glucose concentrations did not differ between regimens (P>0.1). Cats fed once daily had a greater postprandial plasma amino acid response, and greater plasma ghrelin and insulin concentrations (P<0.05). Physical activity was greater in cats fed four times (P<0.05), though energy expenditure was similar between treatments at fasting and in postprandial phases. Finally, cats eating one meal had a lower fasting respiratory quotient (P<0.05). Overall, these data indicate that feeding once a day may be a beneficial feeding management strategy for indoor cats to promote satiation and lean body mass.

Plasma homocysteine concentration in privately owned healthy adult cats: assessment of biological determinants and establishment of a reference interval.

OBJECTIVES: The assessment of homocysteine status in diseased cats has indicated high plasma concentrations in chronic kidney disease and yielded conflicting results with respect to cardiovascular disorders. Previous investigations in small populations of normal cats revealed greater-than-expected variability in plasma homocysteine concentration. The purpose of this study was to determine biological determinants and the reference interval (RI) of plasma homocysteine concentration in the feline species, under strict pre-analytical conditions. METHODS: In this prospective observational study, privately owned healthy adult cats underwent a complete physical examination, urinalysis and blood testing, in order to rule out any signs of disease. Plasma homocysteine concentration was measured using high-performance liquid chromatography-tandem mass spectrometry. RESULTS: Of 151 cats recruited, 30 cats were not included owing to abnormal physical examination or fractious behaviour, and 30 cats were excluded based on abnormalities on blood work or urinalysis. Plasma homocysteine concentrations >28 µmol/l were associated with a dietary protein content >9.3 g/100 kcal metabolisable energy. The RI for plasma homocysteine concentration was determined to be 6.2-52.3 µmol/l. CONCLUSIONS AND RELEVANCE: Normal values for plasma homocysteine concentration in cats have a wide RI, suggesting high inter-individual variability. Whether some healthy cats exhibit impaired homocysteine metabolism remains to be elucidated.

In vitro assessment of the long-term stability of the inhibitory effects of canine and feline plasma on MMP 2 and 9.

PURPOSE: To evaluate the effect of increasing storage time on the inhibitory effects of canine and feline plasma on matrix metalloproteinases (MMP) 2 and 9 in vitro. METHODS: Matrix metalloproteinases 2 and 9 activity in the presence of canine plasma stored for 57, 155, 222, 316, 367, and 438 days, and feline plasma stored for 17, 198, 565, and 954 days was assayed using a commercially available colorimetric assay kit. RESULTS: For canine plasma, the MMP 2 activity for older samples was not significantly different than the 57-day sample (P = 0.2025-0.9033). Two canine samples had significantly lower MMP 9 activity than the 57-day sample (367 days: P = 0.0099, 438 days: P = 0.0348, others P = 0.0778-0.9928). For feline plasma, storage time did not significantly affect inhibition of MMP 2 and MMP 9 activity (ANOVA, P = 0.2688 and P = 0.2404, respectively). CONCLUSIONS: Increasing storage time does not significantly decrease the inhibiting activity of plasma on MMP 2 and 9 for up to 14 months in dogs and 31 months in cats.

Analytical quality assessment and method comparison of immunoassays for the measurement of serum cobalamin and folate in dogs and cats.

Serum cobalamin and folate are often measured in cats and dogs as part of laboratory testing for intestinal disease, small intestinal dysbiosis, or exocrine pancreatic deficiency. We performed an analytical validation of human immunoassays for cobalamin and folate measurement (AIA-900 analyzer, Tosoh Bioscience) and compared results with those obtained using chemiluminescence assays (Immulite 2000 analyzer, Siemens Medical Solutions Diagnostics). Accuracy, precision, total observable error (TEobs%), and σ values were calculated for the immunoassays. Correlation and agreement were evaluated with Deming regression, Passing-Bablok regression, and Bland-Altman analysis. Cobalamin intra-assay and inter-assay CVs were 1.8-9.3% and 2.6-6.8%, respectively. Folate intra-assay and inter-assay CVs were 1.5-9.1% and 3.4-8.1%, respectively. TEobs (%) were ≤19 and ≤31 for cobalamin and folate, respectively. Sigma values were 3.60-11.50 for cobalamin and 2.90-7.50 for folate. Regression analysis demonstrated very high or high correlations for cobalamin [ r = 0.98 (dogs), 0.97 (cats)] and folate [ r = 0.88 (dogs), 0.92 (cats)] but Bland-Altman analysis revealed poor agreement for both. The immunoassays had good analytical performance for measuring cobalamin and folate in both species. Results obtained by the 2 analyzers cannot be used interchangeably and should be interpreted using instrument-specific reference intervals. Further studies are required to establish immunoassay-specific reference intervals and to evaluate the diagnostic performance and clinical utility of the analyzer for these analytes.

Assessment of postoperative inflammatory markers and pain in cats after laparoscopy and miniceliotomy ovariectomy.

Videosurgery is increasingly used in veterinary medicine. Compared with open surgery, it has been shown to cause minimal pain and promote a more rapid recovery. There are various methods of assessing pain and postoperative inflammation in cats, although their particular behaviours may make these assessments difficult. The aim of this study was to compare levels of postoperative pain and inflammation after laparoscopic ovariectomy with an open minimally invasive technique. Twenty queens were randomly divided into two groups based on the method of haemostasis and surgical technique: (1) laparoscopic ovariectomy using a miniloop (miniloop group (MG)); and (2) minilaparotomy using a Snook hook (control group (CG)). Heart rate (HR), respiratory rate (RR), end tidal CO2 (EtCO2) and body temperature were assessed using a multiparametric monitor during anaesthesia and surgery at defined surgical time points (preincision, left ovary manipulation, right ovary manipulation and skin suture). Blood samples (2 mL each) were collected from the jugular vein before surgery and 1, 12, 24, 48 and 72 hours, and 10 days, after endotracheal extubation for blood count analysis and to assess total protein and acute phase proteins (APP). EtCO2 and RR were significantly higher in MG patients (P<0.001). HR was higher in the CG group for the duration of surgery (P=0.01). Temperature was significantly lower in MG patients (P<0.001). Pain assessment by dynamic interactive visual analogue scale showed no difference between groups or at specific moments of time within groups. Segmented neutrophil counts increased at 24 hours postoperatively and peaked at 48 and 72 hours in MG (P=0.01). The most important result among APPs was haptoglobin, which peaked at 72 hours in MG patients (P=0.001). Patients undergoing minilaparotomy and laparoscopy showed comparable postoperative pain. However, inflammatory changes such as APPs and neutrophil counts were increased in the laparoscopic group.

In vitro assessment of quality of citrate-phosphate-dextrose-adenine-1 preserved feline blood collected by a commercial closed system.

BACKGROUND: Optimal procedure for storage of feline blood is needed. Open-collection systems have been employed in feline medicine, thus limiting the possibility for storage. OBJECTIVES: To evaluate indicators of quality of feline blood stored for 35 days at +4°C in a closed-collection system specifically designed for cats. ANIMALS: Eight healthy adult European domestic shorthair cats with a weight of 5-6.8 kg. METHODS: This is a case series study. A bacteriological test, CBC, blood smear, pH, osmotic fragility, 2,3-diphosphoglycerate (2,3-DPG), and adenosine triphosphate (ATP) measurement were performed weekly on whole blood (WB) units from day 1 to day 35 after donation. The hemolysis index, lactate and potassium concentrations, prothrombin time (PT), activated partial thromboplastin time (aPTT), and fibrinogen were measured on plasma aliquots. RESULTS: One out of eight blood units (BUs) had bacterial growth (Serratia marcescens) at day 35. No significant differences were found regarding CBC, morphology, pH, and osmotic fragility. Despite high inter-individual variability and low starting levels, significant decreases in the mean concentrations of 2,3-DPG (T0 1.99 mmol/g Hb, SD 0.52, T35 1.25 mmol/g Hb, SD 1.43; P = .003) and ATP (T0 1.45 mmol/g Hb, SD 0.71, T35 0.62 mmol/g Hb, SD 0.51; P < .001) were detected during the study, as opposed to an increase in hemolysis (T0 0.11 mmol/L, SD 0.07, T35 0.84 mmol/L, SD 0.19; P < .001), lactate (T0 3.30 mmol/L, SD 0.86, T35 13.36 mmol/L, SD 2.90; P < .001), and potassium (T0 3.10 mmol/L, SD 0.21, T35 4.12 mmol/L, SD 0.35; P < .001) concentrations. CONCLUSIONS AND CLINICAL IMPORTANCE: The commercial BU kit is appropriate for blood collection and conservation of WB in cats. The maintenance of WB quality indicators during storage is essential for future improvements of feline transfusion medicine.

Assessment of platelet function in healthy cats in response to commonly prescribed antiplatelet drugs using three point-of-care platelet function tests.

Objectives The objective was to determine if decreased platelet function could be detected after treatment with aspirin and/or clopidogrel in healthy cats using three point-of-care platelet function tests that evaluate platelet function by different methods: Multiplate (by impedance), Platelet Function Analyzer 100 (by mechanical aperture closure) and Plateletworks (by platelet counting). Methods Thirty-six healthy cats were randomly assigned to receive one of three oral treatments over an 8 day period: (1) aspirin 5 mg q72h; (2) aspirin 20.25 mg q72h; or (3) clopidogrel 18.75 mg q24h. Cats treated with 5 and 20.25 mg aspirin also received clopidogrel on days 4-8. Platelet aggregation in response to adenosine diphosphate and collagen ± arachidonic acid was assessed on days 1 (baseline), 4 and 8. Aspirin and clopidogrel metabolites were measured by high-performance liquid chromatography. Platelet function in response to treatment was analyzed by ANCOVA, linear regression and Spearman correlation. Results The only solitary aspirin effect was detected using Plateletworks with collagen in cats treated with 20.25 mg. The only effect detected by Multiplate was using arachidonic acid in cats treated with both aspirin 20.25 mg and clopidogrel. All clopidogrel treatment effects were detected by Platelet Function Analyzer 100, Plateletworks (adenosine diphosphate) and Plateletworks (collagen). Drug metabolites were present in all cats, but concentrations were minimally correlated to platelet function test results. Conclusions and relevance Platelet Function Analyzer 100 and Plateletworks using adenosine diphosphate ± collagen agonists may be used to detect decreased platelet function in response to clopidogrel treatment. Either aspirin is not as effective an antiplatelet drug as clopidogrel, or the tests used were not optimal to measure aspirin effect. Cats with heart disease are commonly prescribed antiplatelet drugs to decrease the risk of aortic thromboembolism. Platelet Function Analyzer 100 and Plateletworks may be useful for confirming clopidogrel treatment in these cats.

Assessment of five formulae to predict post-transfusion packed cell volume in cats.

This retrospective study aimed to identify the most accurate formula for estimating the increase in packed cell volume (PCV) after whole blood transfusion of cats, as several formulae have been reported but not validated. Forty cats, of varying breeds and gender, were included from two referral institutions after database searches over a 13 year period. Five formulae were used to calculate an estimated post-transfusion PCV based on the re-working of formulae for determining the volume of donor blood to be transfused; three formulae were derived from those previously reported in the feline literature and two from human paediatric medicine, where a similar mean blood volume has been described. Cats were subdivided into two groups, the first consisting of 17 cats with non-regenerative anaemia and the second consisting of 23 cats with ongoing losses such as haemolysis and haemorrhage; it was hypothesised that formulae could be more accurate for group 1 cats, whereas formulae applied to group 2 cats could have overestimated the post-transfusion PCV. Bland-Altman analysis was performed for all cats to compare the actual increase in PCV with the calculated increase for the five formulae. Formula 1 (PCV % increase = volume of blood transfused in ml/2 × bodyweight in kg) performed best overall and is easy to calculate; however, no single formula was highly accurate at predicting the PCV increase after whole blood transfusion in cats and, owing to the wide confidence intervals, these formulae should be applied judiciously in the clinical setting.

Assessment of blood types of Ragdoll cats for transfusion purposes.

BACKGROUND: Transfusion of compatible blood types ensures the vitality of transfused erythrocytes and avoids transfusion reactions. Cats with types A, B, and AB blood should receive transfusions of the same blood type. In a feline blood donor program, it is therefore essential to have blood donors of all blood types available. OBJECTIVES: The objectives of this study were the identification of the 3 feline blood types in Ragdoll cats, the comparison of their frequencies with those of Domestic Shorthair (DSH) cats, and the determination of whether Ragdolls are suitable donors in a feline blood donor program. METHODS: The blood type was determined by gel column agglutination from Ragdoll cats. The relationships between phenotypic traits, the origin of the cats, and the different blood types were examined. The frequencies for potential transfusion reactions and the risk for neonatal isoerythrolysis (NI) were estimated. RESULTS: Of 61 typed Ragdolls, 77.1% had type A, 4.9% type B, and 18% type AB blood. The frequency of blood type A in Ragdolls was lower than in DSH cats (P = .02), while the frequency of blood type AB in Ragdolls was higher than in DSH cats (P = .0002). No relationship was found between blood type and origin of the cat or phenotypic traits. The estimated frequencies of major and minor transfusion reactions following an unmatched transfusion between Ragdolls (donors and recipients), Ragdoll donors and DSH recipients, and DSH donors and Ragdoll recipients were 4.7%, 6.7%, 4.6%, and 18.5%, 20.8%, 7.6%, respectively. The frequency of kittens at risk for NI was 5%. CONCLUSION: The presence of all 3 feline blood types and a relatively high incidence of AB type cats make Ragdolls an ideal donor breed to include in feline blood transfusion programs.

Assessment of the Accutrend GCT and PTS CardioChek meters to measure blood triglyceride concentrations in cats.

Point-of-care (POC) meters that determine whole blood triglyceride (TG) concentrations are used in human medicine to monitor both fasting and post-prandial TG concentrations. The aim of this study was to evaluate their performance for determining feline TG concentrations. A total of 116 venous blood samples were collected from 55 cats. TG concentrations were measured in whole blood using two meters: the Accutrend glucose cholesterol triglyceride (GCT) (GCT: Roche Diagnostics) and PTS CardioChek (PTS - Polymer Technology Systems), and results compared to those determined by a National Association of Testing Authorities (NATA) accredited veterinary laboratory. The GCT was not suitable for use in cats with normal TG concentrations (<0.9 mmol/l), as it overestimated almost 80% of the values; however, this device performed better with TG concentrations between 0.9 and 2.0 mmol/l. The PTS meter performed well in cats with normal TG concentrations, correctly classifying 90% of values as 'normal', and fairly well with TG concentrations <2.0 mmol/l. The PTS meter could be used to determine whether cats have normal fasting TG concentrations or predict mild elevations in serum TG, whereas the GCT meter can only be used to predict cats with elevated TG concentrations. Although both meters have limitations in determining some TG concentrations, the PTS in particular, could be used as a screening tool to distinguish normal cats to those with hypertriglyceridaemia.

Assessment of oxidative stress in leukocytes and granulocyte function following oral administration of a silibinin-phosphatidylcholine complex in cats.

OBJECTIVE: To determine the effect of oral administration of a silibinin-phosphatidylcholine complex (SPC) on oxidative stress in leukocytes and granulocyte function in healthy cats. ANIMALS: 10 purpose-bred adult cats. PROCEDURES: Cats were administered SPC (10 mg/kg/d) orally for 5 days; blood samples were collected prior to and immediately after the 5-day treatment period. Leukocytes were incubated with monochlorobimane for detection of reduced glutathione (GSH) via flow cytometry. Leukocytes were also incubated with dihydrorhodamine 123 and mixed with Escherichia coli conjugated to a fluorescent marker to measure E coli phagocytosis and the subsequent oxidative burst via flow cytometry. Activities of the antioxidant enzymes superoxide dismutase and glutathione peroxidase, along with the reduced glutathione-to-oxidized glutathione (GSH:GSSG) ratio and a measure of lipid peroxidation (malondialdehyde concentration [micromol/L of blood]), were measured spectrophotometrically. RESULTS: The mean fluorescence intensity (MFI), representing GSH content, increased significantly in feline lymphocytes and granulocytes following 5 days of oral administration of SPC. Mean +/- SD lymphocyte MFI significantly increased from 27.8 +/- 9.0 to 39.6 +/- 6.7, and the granulocyte MFI increased from 508.6 +/- 135.6 to 612.1 +/- 122.9. Following 5 days of SPC administration, the percentage of phagocytic cells that were responding optimally significantly increased (from 37 +/- 11.8% to 45 +/- 17.5%). Other measures of oxidative stress did not change significantly. CONCLUSIONS AND CLINICAL RELEVANCE: In cats, oral administration of supplemental SPC appears to increase granulocyte GSH content and phagocytic function, both of which would be potentially beneficial in cats with diseases associated with oxidative stress.

Clinical assessment of repeated propofol-associated anesthesia in cats.

OBJECTIVE: To assess the effects of repeated episodes of propofol-associated anesthesia on quality of recovery from anesthesia, clinical status, and erythrocyte physiology in cats. DESIGN: Original study. ANIMALS: 37 cats undergoing short-duration anesthesia for radiotherapy. PROCEDURES: Twice daily on 5 consecutive days, 13 cats with squamous cell carcinoma of the nasal planum (group 1) underwent anesthesia: first via administration of propofol or a midazolam (0.2 mg/kg [0.09 mg/lb])-propofol combination and then via administration of ketamine and midazolam each day (latter data were not analyzed). During a 19-day period, 24 cats with vaccine associated sarcoma (group 2) were anesthetized 12 times with propofol or a midazolam-propofol combination. Anesthesia was maintained with propofol in both groups. Hematologic analysis was performed before, during, and on completion of radiotherapy; changes in Hct and hemoglobin concentration between groups were compared. RESULTS: Mean duration of anesthesia was 8.1 minutes (range, 5 to 20 minutes); no adverse events were detected during recovery. Total dose of propofol administered did not differ between groups 1 (6.34 mg/kg [2.88 mg/lb]) and 2 (4.71 mg/kg [2.14 mg/lb]). Midazolam administration decreased the propofol dose by 26%. Overall decreases from baseline in Hct and hemoglobin concentration were not significantly different between the 2 groups, nor clinically important; however, compared with baseline, values in group 2 were significantly lower after 6 and 12 anesthetic episodes for both protocols. Heinz bodies were identified in low numbers in both groups during radiotherapy. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that repeated propofol-associated short-duration anesthesia does not lead to clinically relevant hematologic changes in cats undergoing short-duration radiotherapy.

Comparison of a new device for blood sampling in cats with a vacuum tube collection system - plasma biochemistry, haematology and practical usage assessment.

Using paediatric devices to collect venous blood from a cephalic vein in cats offers numerous practical advantages over traditional jugular venepuncture and vacuum closed systems: minimal restraint is required; there is minimal risk of serious injury to the cat; the discomfort associated with venepuncture is reduced by the use of small diameter (25 gauge) needles; very small volumes (200 microl) of blood are extracted; and the risk of vein collapse or haematoma is low. The aim of this study was to compare the haematological and plasma chemistry results obtained from six healthy cats using the two sampling techniques. Five plasma biochemical analytes were measured and a complete haematological examination was performed on each specimen. No clinically relevant difference between the two blood sampling techniques was observed for any variable, indicating that paediatric devices provide a useful alternative to vacuum tubes for venous blood collection in the cat.

Bayesian inference in a hidden stochastic two-compartment model for feline hematopoiesis.

In this paper, we describe a hidden two-compartment stochastic process used to model the kinetics of feline hematopoietic stem cells (HSCs) in continuous time. Because of the experimental design and data collection scheme, the inferential task presents numerous challenges. While the hematopoietic process evolves in continuous time, the observations are collected only at discrete irregular times and are a probabilistic function of the state of the process. In addition, the animals go through an experimental procedure such that their reserve of HSCs is severely depleted at the start of the observation period. This impedes any approximation of the hematopoietic process with a continuous state-space process (normal approximation of the transition probabilities would be inaccurate when the state of the process, i.e. the number of stem cells, is small). We implement a Markov chain Monte Carlo algorithm that allows us to estimate the posterior distribution of the parameters of the hematopoietic process while maintaining its state-space discrete (i.e. without using any approximation). We show the performance of the algorithm on simulated data. Finally, we apply the algorithm to data on multiple experimental cats and provide estimates of the rates of the fates of feline HSCs. The obtained estimates are in agreement with the estimates obtained with different methods published in the medical literature. However, the proposed approach makes a more efficient use of the data and hence the parameter estimates are much more accurate than the one obtained with the methods previously proposed.

Basal plasma insulin and homeostasis model assessment (HOMA) are indicators of insulin sensitivity in cats.

The objective of this study was to compare simpler indices of insulin sensitivity with the minimal model-derived insulin sensitivity index to identify a simple and reliable alternative method for assessing insulin sensitivity in cats. In addition, we aimed to determine whether this simpler measure or measures showed consistency of association across differing body weights and glucose tolerance levels. Data from glucose tolerance and insulin sensitivity tests performed in 32 cats with varying body weights (underweight to obese), including seven cats with impaired glucose tolerance, were used to assess the relationship between Bergman's minimal model-derived insulin sensitivity index (S(I)), and various simpler measures of insulin sensitivity. The most useful overall predictors of insulin sensitivity were basal plasma insulin concentrations and the homeostasis model assessment (HOMA), which is the product of basal glucose and insulin concentrations divided by 22.5. It is concluded that measurement of plasma insulin concentrations in cats with food withheld for 24 h, in conjunction with HOMA, could be used in clinical research projects and by practicing veterinarians to screen for reduced insulin sensitivity in cats. Such cats may be at increased risk of developing impaired glucose tolerance and type 2 diabetes mellitus. Early detection of these cats would enable preventative intervention programs such as weight reduction, increased physical activity and dietary modifications to be instigated.

Assessment of the hemodynamic effects of lidocaine administered IV in isoflurane-anesthetized cats.

OBJECTIVE: To determine the hemodynamic effects of lidocaine (administered IV to achieve 6 plasma concentrations) in isoflurane-anesthetized cats. ANIMALS: 6 cats. PROCEDURE: Cats were anesthetized with isoflurane in oxygen (end-tidal isoflurane concentration set at 1.25 times the predetermined individual minimum alveolar concentration). Lidocaine was administered IV to each cat to achieve target pseudo-steady-state plasma concentrations of 0, 3, 5, 7 9, and 11 microg/mL, and isoflurane concentration was reduced to an equipotent concentration. At each plasma lidocaine concentration, cardiovascular and blood gas variables; PCV; and plasma total protein, lactate, lidocaine, and monoethylglycinexylidide concentrations were measured in cats before and during noxious stimulation. Derived variables were calculated. RESULTS: n isoflurane-anesthetized cats, heart rate, cardiac index, stroke index, right ventricular stroke work index, plasma total protein concentration, mixed-venous PO2 and hemoglobin oxygen saturation, arterial and mixed-venous bicarbonate concentrations, and oxygen delivery were significantly lower during lidocaine administration, compared with values determined without lidocaine administration. Mean arterial pressure, central venous pressure, pulmonary artery pressure, systemic and pulmonary vascular resistance indices, PCV, arterial and mixed-venous hemoglobin concentrations, plasma lactate concentration, arterial oxygen concentration, and oxygen extraction ratio were significantly higher during administration of lidocaine, compared with values determined without lidocaine administration. Noxious stimulation did not significantly affect most variables. CONCLUSIONS AND CLINICAL RELEVANCE: In isoflurane-anesthetized cats, although IV administration of lidocaine significantly decreased inhalant requirements, it appeared to be associated with greater cardiovascular depression than an equipotent dose of isoflurane alone. Administration of lidocaine to reduce isoflurane requirements is not recommended in cats.

Assessment of five portable blood glucose meters for use in cats.

OBJECTIVE: To evaluate the clinical and analytic accuracy of 5 portable blood glucose meters (PBGM) in cats, with emphasis on the detection of potential sources of error. ANIMALS: 200 cats. PROCEDURE: Venous blood glucose readings from 5 PBGM were compared with the results of a hexokinase reference method. Agreement among methods was determined by error grid analysis and statistical methods. RESULTS: A total of 2,975 PBGM readings and 513 reference values were analyzed. The accuracy of the PBGM varied in different glycemic ranges. The largest differences between PBGM readings and reference values were in the high glycemic range; 4 PBGM underestimated and 1 PBGM overestimated the reference values in most instances. In the low and reference glycemic ranges, the absolute differences between PBGM readings and reference values were small. Despite the analytic differences in accuracy, 4 PBGM had 100% and 1 PBGM had 98.7% of readings in the clinically acceptable values of the error grid analysis. Within- and between-day precisions were good for all PBGM. Significant differences were not detected between readings of EDTA and lithium-heparinized blood and fresh blood without anticoagulant. Compared with these blood types, 1 PBGM had significantly different readings with fluoride anticoagulated blood. In blood samples with a low Hct, all PBGM overestimated glucose concentrations. Sample volumes < 3 microl resulted in inaccurate measurements in 3 PBGM. CONCLUSIONS AND CLINICAL RELEVANCE: Performance varied among the 5 PBGM analyzed; however, all PBGM were deemed acceptable for clinical use in cats.

Glycosylated hemoglobin concentration for assessment of glycemic control in diabetic cats.

Blood glycosylated hemoglobin (GHb) concentration was quantified in 84 healthy cats, 9 cats with stress-induced hyperglycemia, 37 cats with newly diagnosed diabetes mellitus, and 122 diabetic cats treated with insulin or glipizide. Diabetic control was classified as good or poor in insulin-treated or glipizide-treated cats based on review of history, physical examination findings, changes in body weight, and measurement of blood glucose concentrations. Blood GHb concentration was determined using an affinity chromatography assay. Mean blood GHb concentration was similar for healthy normoglycemic cats and cats with transient, stress-induced hyperglycemia, but was significantly (P < .001) higher in untreated diabetic cats when compared with healthy normoglycemic cats. Mean blood GHb concentration was significantly (P < .001) higher in 84 cats with poorly controlled diabetes mellitus when compared with 38 cats in which the disease was well controlled. Mean blood GHb concentration decreased significantly (P < .01) in 6 cats with untreated diabetes mellitus after insulin and dietary treatment. A similar significant (P < .01) decrease in mean blood GHb concentration occurred in 7 cats with poorly controlled diabetes mellitus after diabetic control was improved by an increase in insulin dosage from 1.1 +/- 0.9 to 1.4 +/- 0.6 U/kg/ 24 h and by feeding a diet containing increased fiber content and in 6 cats with transient diabetes mellitus 8.2 +/- 0.6 weeks after discontinuing insulin treatment. There was a significant (P < .01) stress-induced increase in mean fasting blood glucose concentration and mean blood glucose concentration for 12 hours after administration of insulin or glipizide but no change in mean blood GHb concentration in 5 docile diabetic cats 12.2 +/- 0.4 weeks after the cats became fractious as a result of frequent hospitalizations and blood samplings. Results of this study suggest that evaluation of blood GHb concentration may be a clinically useful tool for monitoring glycemic control of diabetes in cats.

A study of the use of a transdermal fentanyl patch in cats.

A transdermal therapeutic system (TTS) has been developed for the continuous delivery of fentanyl citrate to provide ongoing analgesia in human patients with chronic pain. Several researchers believe that fentanyl transdermal patches have a place in postoperative pain control. The purpose of this study was to determine whether transdermal technology is an effective way of administering fentanyl to feline patients. Fentanyl patches were applied to the skin of six cats, and blood samples for fentanyl analysis were collected over 104 hours. This study establishes that the transdermal patch technology is an effective, long-lasting, cost-effective, noninvasive, and well-tolerated mode of deliverying fentanyl to cats.