Influence of the observer's level of experience on systolic and diastolic arterial blood pressure measurements using Doppler ultrasonography in healthy conscious cats.

The objective of this study was to determine the influence of the observer's level of experience on within- and between-day variability, and the percentage of successful systolic (SAP) and diastolic arterial blood pressure (DAP) measurements obtained by Doppler ultrasonography (DU) in awake cats. For this purpose, six healthy conscious cats were used and four observers with different levels of training performed 144 SAP and DAP measurements on 4 days using DU. Measurements were recorded five consecutive times, and mean values were used for statistical analysis. Only the two most skilled observers - a PhD student in cardiology and a Dipl ECVIM-CA (cardiology) - had within- and between-day coefficients of variation (CVs) for SAP ⩽16% (13-16%). Conversely, the two less experienced observers - a fifth-year student and an assistant - had high between-day CVs (61% and 73%). For DAP, only the most experienced observer (Dipl ECVIM-CA) succeeded in 100% of the attempts, with within- and between-day CVs of 11% and 4%, respectively. Conversely, DAP could not be measured by the other three observers in 8%, 19% and 56% of attempts (from the highest to the lowest level of experience); therefore, the corresponding CV values could not be calculated. In conclusion, SAP may be assessed using DU in healthy awake cats with good repeatability and reproducibility by a well-trained observer. Measurement of DAP is more difficult than of SAP, and needs a longer training period, which represents one of the limitations of DU in cats.

Basal plasma concentrations of routine variables and packed cell volume in clinically healthy adult small-sized dogs: effect of breed, body weight, age, and gender, and establishment of reference intervals.

BACKGROUND: Plasma variables may be affected by breed or body weight (BW). Small-sized dogs are very common, but no specific reference intervals (RI) are used. OBJECTIVES: The primary objective of this prospective study was to assess the potential effect of breed, BW, age, and sex on routine plasma analytes and packed cell volume (PCV) in small-sized dogs. A secondary objective was to establish RI in this small-sized population. METHODS: Blood was sampled under standardized conditions from healthy dogs. PCV and 15 routine plasma variables were measured at the same laboratory. Effects of breed, BW, age, and sex were tested using a general linear model. The procedure recommended by the Clinical and Laboratory Standards Institute was used to establish RI. RESULTS: In this study, 154 healthy dogs from 7 breeds were prospectively included. Although a significant effect of breed, BW, sex, or age was evidenced for most variables (except plasma sodium, phosphates, and triglycerides), it was considered as clinically irrelevant. More strikingly, the percentage of values in the reference sample group under the lower limit of the laboratory's RI ranged from 3.8% to 76.6% for 9 variables, and those higher than the upper limit of the laboratory's RI ranged from 4.5% to 9.7% for 7 variables. For example, the RI for creatinine in small-sized dogs was 45-90 µmol/L (vs 54-144 µmol/L for the general dog population). CONCLUSION: Specific RI should be considered for PCV and selected plasma variables in small-sized dogs.

Basal plasma concentrations of N-terminal pro-B-type natriuretic peptide in clinically healthy adult small size dogs: effect of body weight, age, gender and breed, and reference intervals.

Plasma NT-proBNP has previously been evaluated in dogs with degenerative mitral valve disease (DMVD). However, reference intervals (RI) established according to the Clinical Laboratory and Standards Institute (CLSI) recommendations have never been provided. The objectives of this prospective study were to assess effects of breed, body weight, age, and sex on plasma NT-proBNP, and to establish RI according to CLSI for this biomarker in a large population of dogs predisposed to DMVD. 183 Healthy small-sized dogs from 7 breeds were included. Assays were performed by ELISA. Effects of covariates were tested using a general linear model. Although a sex effect was demonstrated (P=0.01), no significant effect of breed, body weight or age was shown. The proposed RI was 157-2842 pmol/L. 7% of dogs had plasma NT-proBNP >2617 pmol/L, and were considered as outliers despite normal cardiovascular examination. In conclusion, plasma NT-proBNP may be high in a few healthy small-sized dogs.

Prospective echocardiographic and tissue Doppler screening of a large Sphynx cat population: reference ranges, heart disease prevalence and genetic aspects.

OBJECTIVES: (1) To investigate heart morphology and function using echocardiography and tissue Doppler imaging (TDI), (2) to determine heart disease prevalence and characteristics, and (3) to assess potential genetic features in a population of Sphynx cats presented for cardiovascular screening. ANIMALS: A total of 147 echocardiographic examinations, including 33 follow-ups, were performed by trained observers on 114 Sphynx cats of different ages (2.62 ± 1.93 years [0.5-10.0]) from 2004 to 2011. METHODS: Sphynx cats underwent a physical examination, conventional echocardiography, and, if possible, two-dimensional color TDI. RESULTS: Conventional echocardiographic findings included 75/114 normal (65.8%) and 39/114 (34.2%) abnormal examinations with a diagnosis of either congenital heart diseases (n = 16) or hypertrophic cardiomyopathy (HCM, n = 23). In adult healthy cats, a significant body weight effect was observed for several echocardiographic variables, including end-diastolic left ventricular (LV) free wall (P < 0.01), interventricular septum (P < 0.001), and LV diameter (P < 0.001). Mitral valve dysplasia (MVD) was observed as a single or associated defect in 15/16 cats with congenital heart diseases. A significant increase in HCM prevalence (P < 0.001) was observed according to age. The pedigree analysis of a large family (n = 81) suggested an autosomal dominant mode of inheritance with incomplete penetrance for HCM. CONCLUSIONS: Body weight should be taken into account when interpreting values of diastolic myocardial wall thicknesses in Sphynx cats. Additionally, HCM and MVD are two relatively common heart diseases in this feline breed. More pedigree data are required to confirm the inheritance pattern of HCM at the breed level.

Comparison of pharmacokinetic variables for creatinine and iohexol in dogs with various degrees of renal function.

OBJECTIVE: To compare pharmacokinetics and clearances of creatinine and iohexol as estimates of glomerular filtration rate (GFR) in dogs with various degrees of renal function. ANIMALS: 50 Great Anglo-Francais Tricolor Hounds with various degrees of renal function. PROCEDURES: Boluses of iohexol (40 mg/kg) and creatinine (647 mg/kg) were injected IV. Blood samples were collected before administration and 5 and 10 minutes and 1, 2, 4, 6, and 8 hours after administration. Plasma creatinine and iohexol concentrations were assayed via an enzymatic method and high-performance liquid chromatography, respectively. A noncompartmental approach was used for pharmacokinetic analysis. Pharmacokinetic variables were compared via a Bland-Altman plot and an ANOVA. RESULTS: Compared with results for creatinine, iohexol had a significantly higher mean ± SD plasma clearance (3.4 ± 0.8 mL/min/kg vs 3.0 ± 0.7 mL/min/kg) and a significantly lower mean volume of distribution at steady state (250 ± 37 mL/kg vs 539 ± 73 mL/kg), mean residence time (80 ± 31 minutes vs 195 ± 73 minutes), and mean elimination half-life (74 ± 20 minutes vs 173 ± 53 minutes). Despite discrepancies between clearances, especially for high values, the difference was < 0.6 mL/min/kg for 34 (68%) dogs. Three dogs with a low GFR (< 2 mL/min/kg) were classified similarly by both methods. CONCLUSIONS AND CLINICAL RELEVANCE: Plasma iohexol and creatinine clearances can be used interchangeably for screening patients suspected of having chronic kidney disease (ie, low GFR), but large differences may exist for dogs with a GFR within or above the reference range.