Individual glycoside therapy using serum concentration determination in heart insufficiency of horses

23 horses and one donkey with congestive heart failure are treated with a standardized methyldigoxin dose (0.0032 mg/kg of body weight). The therapy is controlled by the serum concentration of the cardiac glycoside. 4 horses have a higher and 13 horses a lower serum concentration as necessary for therapeutic approach. The influence of additional diseases and medications is demonstrated. Finally a rule for the evaluation of the individual therapeutic glycoside-dose is given.     

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.     

Biological variation of canine serum thyrotropin (TSH) concentration

The aim of the present study was to estimate the between-dog, within-dog and analytical components of variance for serum thyrotropin (TSH) in healthy dogs, and to use these components of variance to 1) estimate the critical difference for significance between serial results; 2) assess the utility of the conventional population-based reference interval; 3) set a desirable performance standard for analytical imprecision; and 4) estimate the number of samples required for determination of the true mean value for an individual dog. Using the Immulite test system, TSH was measured in serum samples collected weekly for five weeks from eight clinically healthy dogs. Results were subjected to nested analysis of variance. Between-dog variation was 43.6%, within-dog variation was 13.6%, analytical variation was 8.8%, the one-sided critical difference was 37.8%, the index of individuality was 0.4, the maximum allowable analytical imprecision was 6.8%, and the number of samples required to determine the true mean value in a single dog was 40. In practical terms, the present study indicated that the analytical imprecision of canine serum TSH measurement should be < 7%, and that comparing a single serum TSH measurement from an individual dog to the conventional population-based reference range may be too insensitive to detect small but important changes in the serum TSH level of that particular dog. In addition, when treating a hypothyroid dog, serum TSH, measured on a weekly basis, should decrease by at least one-third before any effect of exogenous thyroxine supplementation can be said to have influenced the serum TSH level.     

Quantitative determination of progesterone (P4) in canine blood serum using an enzyme-linked fluorescence assay

Progesterone (P4) measurement in the peripheral blood is an objective parameter for determination of reproductive functions in the bitch. This study evaluates an enzyme-linked fluorescence assay (ELFA) (Biomerieux, France) for the determination of progesterone validated for use in human. The ELFA is to be performed on the MiniVidas automated analyser which provides quantitative results within 45 min. Blood samples from a total of 27 female dogs of different breeds were used. To test the correctness of the ELFA 15 blood samples with a range of 0.3-40.0 ng/ml were compared to a radioimmunoassay (RIA) validated in the dog. The values obtained with the MiniVidas showed a high agreement (mean deviation 15%), deviations were in both directions and the correlation coefficient was 0.989. The coefficient of correlation according to Passing-Bablok test was 0.995. The intra-assay reproducibility in the MiniVidas system was tested on five samples (mean values 61.8, 6.8, 51.4, 43.7 and 1.1 ng/ml). The coefficients of variation (CV; 10-12 replicates) were 3.4%, 6.7%, 2.6%, 3.1% and 25.4%, respectively. Four serum samples (mean value 47.0, 15.1, 49.1 and 4.0 ng/ml) from different bitches were assayed singly in 10 separate series to test the inter-assay variability. The corresponding CV was 2.1%, 2.2%, 3.1% and 4.3% respectively. Samples from three dogs were used to test the accuracy of the assay. These samples were diluted (1/2, 1/4, 1/8 and 1/16) with charcoal-stripped human serum (Biomerieux, France) and tested in three runs. The expected values were met in a range of 60-75%. Measurement of progesterone for the detection of ovulation as well as prediction of parturition provided meaningful results. As a conclusion the use of the MiniVidas system for determination of P4 in peripheral blood of the bitch provides rapid and reliable results.     

Cortisol and free thyroxine determination by time-resolved fluorometry in canine serum

Validation for canine serum of 2 commercially available time-resolved fluoroimmunoassays (TR-FIAs) designed for analysis of cortisol and free thyroxine (fT4) in human serum was carried out. Included was the study of interference by hemolysis, lipemia, and bilirubinemia. With the dissociation enhancement lanthanide fluoroimmunoassay kits, the intra-assay coefficient of variation (CV) ranged from 6.4% to 8.7% for cortisol and from 5.3% to 9.8% for fT4; the interassay CVs ranged from 5.8% to 10.8% and from 3.9% to 14.1%, respectively. Accuracy was evaluated by comparing cortisol and fT4 results obtained with TR-FIA and those obtained with a validated enzyme-linked immunosorbent assay (ELISA) and an equilibrium dialysis (ED) assay, respectively. The regression equations obtained were y = 0.57x + 1.18 (r2 = 0.90) for cortisol and y = 0.87x + 0.82 (r2 = 0.93) for fT4. The limits of detection for cortisol and fT4 were 4.84 nmol/L and 2.68 pmol/L, respectively. The results of adrenocorticotropin-stimulation and dexamethasone-suppression tests were similar to those published previously; likewise, serial dilution of a canine serum sample with a high cortisol content demonstrated that the TR-FIA was immunologically specific. Serial dilution of a serum sample with a high fT4 concentration showed a methodologic bias, a dependence on serum binding capacity, which indicates that the results obtained with this method should be interpreted with caution. Finally, hemolysis and lipemia significantly interfered with cortisol and fT4 measurements, whereas bilirubinemia did not affect the results.     

Brain natriuretic peptide concentration in dogs with heart disease and congestive heart failure

Plasma brain natriuretic peptide concentration ([BNP]) is high in humans with cardiac disease and is further increased with congestive heart failure (CHF). The hypotheses of this study were that dogs with moderate to severe mitral regurgitation due to myxomatous mitral valve disease (MVD) would have increased plasma [BNP] compared to normal dogs, that plasma [BNP] would be higher in dogs with CHP, and that plasma [BNP] would predict premature death from cardiovascular disease. The study population consisted of 34 dogs: 9 normal dogs and 25 dogs with MVD. Patients were divided into 4 groups: group 1-10 dogs with moderate to severe MVD and no radiographic evidence of CHF; group II--6 dogs with severe MVD and mild CHF; group III--7 dogs with severe MVD and moderate CHF; and group IV--2 dogs with severe MVD and severe CHF. Diagnostic tests included thoracic radiographs, an echocardiogram, a serum chemistry profile, and the measurement of plasma [BNP] by a canine-specific radioimmunoassay. There was a significant positive correlation between the plasma [BNP] and heart disease/failure groups (P = .0036). Plasma [BNP] increased with progressively increasing severity of MVD and CHE Group I dogs had higher plasma [BNP] than did control dogs (P < .0001), and plasma [BNP] was higher in dogs with CHF (groups II-IV versus group I; P = .012). Plasma [BNP] was also weakly positively correlated with left atrial size (r = 0.43, P = .04). For every 10-pg/mL increase in plasma [BNP], the mortality rate over 4 months' time increased approximately 44%.     

Evaluation of a spectrophotometric method for canine serum lipase determination

The British antilewisite butyrate-dithionitrobenzoate (BALB-DTNB) spectrophotometric serum lipase assay was evaluated for precision, accuracy, and diagnostic usefulness in analyzing canine sera. Sera samples from clinically healthy dogs, dogs with experimentally induced pancreatitis, and dogs with spontaneous pancreatitis were analyzed. A titrimetric method of serum lipase determination was used for comparison. Although the BALB-DTNB method was not found to be precise or accurate for determining the lipase activity of canine serum samples, it seemed to be at least as diagnostically useful as the titrimetric procedure. The small sample size requirement and the speed of analysis of the BALB-DTNB procedure are advantages of this method over the titrimetric method, and thus, its use in place of the titrimetric method is justified. A laboratory reference range of 3 to 37 IU/L was determined for canine serum.     

参芪益心方在犬心力衰竭治疗中的应用前景

犬心力衰竭是指心脏不能泵出足够血液以满足全身组织代谢需要的一种病理生理状态及临床综合征。参芪益心方由黄芪、人参、桂枝、丹参等组成,具有益气温阳、活血利水的功效,可用于治疗心力衰竭。笔者从参芪益心方治疗心力衰竭的药效研究、作用机制以及治疗犬心力衰竭的研究现状等方面进行综述,为参芪益心方在犬心力衰竭的临床应用提供参考。     

Evaluation of a commercially available human C-reactive protein (CRP) turbidometric immunoassay for determination of canine serum CRP concentration

Background: Serum C-reactive protein (CRP) is an acute phase marker in dogs that is useful for the diagnosis and monitoring of inflammatory disease. Rapid, reliable, and automated assays are preferable for routine evaluation of canine serum CRP concentration.
Objective: The aim of this study was to evaluate whether canine serum CRP concentration could be measured reliably using an automated turbidometric immunoassay (TIA) designed for use with human serum.
Methods: A commercially available TIA for human serum CRP (Bayer, Newbury, UK) was used to measure canine serum CRP concentration. Cross-reactivity of antigen was evaluated by the Ouchterlony procedure. Intra-and interassay imprecision was investigated by multiple measurements on canine serum samples and serum pools, respectively. Assay inaccuracy was investigated by linearity under dilution and comparison of methodologies (canine CRP ELISA, Tridelta Development Ltd, Kildare, UK). Then the assay was applied to serum samples from 14 clinically healthy dogs, 11 dogs with neoplasia, 13 with infections, 8 with endocrine or metabolic diseases, and 10 with miscellaneous diseases.
Results: Cross-reactivity between canine serum CRP and the anti-human CRP antibody was found. Intra-and interassay imprecision ranged from 5.2% to 10.8% and 3.0% to 10.2%, respectively. Serum CRP concentration was measured in a linear and proportional manner. There was no significant disagreement and there was linear correlation of the results in the comparison of methodologies, except for a slight proportional discrepancy at low CRP concentrations (<10 μg/mL). Dogs with infections had a significantly higher concentration of serum CRP than did all other dogs, and dogs with neoplasia had a significantly higher concentration of serum CRP than did clinically healthy dogs.
Conclusions: Canine serum CRP concentration can be measured reliably using the commercially available TIA designed for human CRP.     

Evaluation of an enzymatic immunoassay for free thyroxine determination in canine serum

Free thyroxine (FT4) and cholesterol were measured in 400 dogs with either suspected hypothyroidism or dermatological signs such that hypothyroidism needed to be ruled out. Hypothyroidism was diagnosed in 68 dogs from the history, physical examination and stated lower reference limit (<7 pmol/L) for FT4 in euthryoid dogs. Dogs with FT4 concentrations in the range 6–9 pmol/L were finally categorized as hypo- or euthyroid either on the basis of retesting after 2 months or on their clinical response to thyroid replacement therapy over at least 2 months.The enzyme immunoassay evaluated in this paper is considered to be of clinical value and offers many advantages compared with radioimmunoassays.Abbreviations FT4 free thyroxine fraction - MEIA microparticle enzyme immunoassay - RIA radioimmunoassays - T4 thyroxine - TBG thyroxine-binding globulin     

Effects of storage on concentration of hydrocortisone (cortisol) in canine serum and plasma

A specific radioimmunoassay was used to measure concentrations of hydrocortisone (cortisol) in the serum and plasma of 4 dogs. Differences (P greater than 0.05) in concentrations of cortisol were not found between serum and plasma (from EDTA-treated and heparinized blood samples). Differences (P greater than 0.05) in serum or plasma concentrations of cortisol were not found between samples stored at 4 C for various times (10 minutes, 10 hours, 40 hours) after collection, but before removal of RBC. In a study designed to determine the stability of cortisol in serum samples stored at room temperature, degradation was dependent on the initial serum concentrations of cortisol. Decreases (P greater than 0.05) did not occur in concentrations of cortisol in serum samples stored up to 15 days when initial concentrations of cortisol were less than 15 ng/ml. However, when initial concentrations of cortisol were approximately 55 ng/ml and 80 ng/ml, significant (P greater than 0.05) degradation occurred after 9 and 5 days of storage, respectively. Results of this investigation indicate that either serum or plasma of dogs is suitable for radioimmunoassay of cortisol and that samples (with and without added coagulants) incubated at 4 C may be left uncentrifuged for up to 40 hours without cortisol degradation. However, prolonged storage of serum at room temperature is detrimental, particularly for samples having large concentrations of cortisol.     

Efficacy and safet of pimobendan in canine heart failure caused by myxomatous mitral valve disease

OBJECTIVES: To evaluate the clinical efficacy and safety of pimobendan by comparing it with ramipril over a six-month period in dogs with mild to moderate heart failure (HF) caused by myxomatous mitral valve disease (MMVD). METHODS: This was a prospective randomised, single-blind, parallel-group trial. Client-owned dogs (n = 43) with mild to moderate HF caused by MMVD were randomly assigned to one of two groups, which received either pimobendan (P dogs) or ramipril (R dogs) for six months. The outcome measures studied were: adverse HF outcome, defined as failure to complete the trial as a direct consequence of HF; maximum furosemide dose (mg/kg/day) administered during the study period; and any requirement for additional visits to the clinic as a direct consequence of HF. RESULTS: Treatment with pimobendan was well tolerated compared with treatment with ramipril. P dogs were 25 per cent as likely as R dogs to have an adverse HF outcome (odds ratio 4.09, 95 per cent confidence interval 1.03 to 16.3, P = 0.046). CLINICAL SIGNIFICANCE: R dogs had a higher overall score and thus may have had more advanced disease than P dogs at baseline (P = 0.04). These results should be interpreted cautiously but such a high odds ratio warrants further investigation.     

Validation of 2 commercially available enzyme-linked immunosorbent assays for adiponectin determination in canine serum samples

The aim of this study was to validate 2 commercially available enzyme-linked immunosorbent assays (ELISAs) for adiponectin in dogs, 1 canine-specific and 1 originally designed for measurements in humans. Intra-assay and interassay precision was evaluated by multiple measurements in canine serum samples, and assay accuracy was indirectly determined by linearity under dilution. Interference caused by hemolysis and lipemia was also studied. Both assays were subsequently used for measuring adiponectin concentrations in clinically healthy dogs and those with different grades of obesity. The intra-assay and inter-assay precision was less than 7.5% and 13.5% in serum samples with low and high adiponectin concentrations, respectively. Lipemia and hemolysis did not affect the results of any of the assays. Both assays were able to differentiate lean dogs from those that were overweight or obese on the basis of the measured adiponectin concentrations. From these results it can be concluded that canine adiponectin concentrations can be measured reliably by means of the 2 ELISAs evaluated in this study.     

Atrial natriuretic peptide concentration in dogs with congestive heart failure, chronic renal failure, and hyperadrenocorticism.

The function of atrial natriuretic peptide (ANP) is claimed to be control of salt and water homeostasis, and thus, the hormone may be involved in the pathogenesis of certain diseases with impaired volume regulation. We, therefore, studied plasma ANP concentration in dogs with chronic renal failure, congestive heart failure, and hyperadrenocorticism. Dogs with chronic renal failure had twofold higher plasma ANP concentration (16.2 +/- 5.8 fmol/ml), compared with healthy dogs (8.3 +/- 3.5 fmol/ml). An even more distinct increase (sixfold) of plasma ANP concentration was found in dogs with congestive heart failure (52.9 +/- 29.7 fmol/ml). In contrast, dogs with hyperadrenocorticism did not have high ANP plasma concentration (5.5 +/- 2.0 fmol/ml). High-performance liquid chromatographic analysis of plasma from dogs with congestive heart failure indicated that, in addition to the normal circulating form of ANP (99-126), the unprocessed precursor ANP (1-126) is detectable in the circulation. These qualitative and quantitative alterations of plasma ANP concentration in dogs further suggest involvement of this peptide in the development and/or maintenance of diseases associated with impaired volume regulation.     

Evaluation of canine congenital heart disease using an echocardiographic algorithm.

Evaluation of canine congenital heart disease presents a diagnostic challenge to many ultrasonographers. To assist clinicians attempting to examine these patients, an echocardiographic algorithm containing the six most common canine congenital heart diseases (i.e., patent ductus arteriosus, subaortic stenosis, pulmonic stenosis, ventricular septal defect, tricuspid dysplasia, and tetralogy of Fallot) is presented. The algorithm focuses on the underlying disease pathogenesis and the resultant changes in cardiac structure and function that can be readily identified during echocardiographic examination. Use of this algorithm provides a framework from which the ultrasonographer gains both experience and confidence in diagnosing congenital heart disease via echocardiography. This algorithm is supported by a number of still figures within the article as well as real-time echocardiographic images available for viewing at AAHA's website, www.aahanet.org.