Veterinary echocardiographers' preferences for left atrial size assessment in cats: the BENEFIT project.

INTRODUCTION/OBJECTIVES: Veterinary echocardiographers' preferences for left atrial (LA) size assessment in cats have not been systematically investigated. The primary aim of this prospective exploratory study was to investigate echocardiographers' preferences concerning LA size assessment in cats. A secondary aim was to investigate echocardiographers' preferences for assessing LA size in subgroups based on geographic, demographic, and professional profiles. ANIMALS, MATERIALS, AND METHODS: An online survey instrument was designed, verified, and distributed globally to veterinary echocardiographers. RESULTS: A total of 655 veterinary echocardiographers from six continents and 54 countries, working in specialty practice (56%) and in general practice (38%), provided data. Linear two-dimensional (2D) technique was favored by most echocardiographers (n = 612) for LA size assessment. Most commonly, respondents combined linear 2D with subjective assessment (n = 227), while 209 used linear 2D-based methods alone. Most echocardiographers using linear 2D-based methods preferred the right parasternal short-axis view and to index the LA to the aorta (Ao). Approximately 10% of the respondents obtained LA dimensions from a right parasternal long-axis four-chamber view. Approximately one-third of echocardiographers that made linear measurements from 2D echocardiograms shared the same preferences regarding cat position, acquisition view, indexing method and time point identification for the LA measurement. The responses were comparably homogeneous across geographic location, level of training, years performing echocardiography, and type of practice. DISCUSSION/CONCLUSION: Most veterinary echocardiographers assessed LA size in cats using linear 2D echocardiography from a right parasternal short-axis view, and indexed LA to Ao. Respondents' preferences were similar over geographic, demographic, and professional backgrounds.

Veterinary echocardiographers' preferences for left atrial size assessment in dogs: the BENEFIT project.

INTRODUCTION/OBJECTIVES: Veterinary echocardiographers' preferences for left atrial (LA) size assessment in dogs have never been systematically investigated. The primary aim of this international survey study was to investigate echocardiographers' preferences for LA size assessment in dogs. The secondary aim was to investigate echocardiographers' preferences for assessing LA size in subgroups based on geographic, demographic, and professional profiles. ANIMALS, MATERIALS, AND METHODS: An online survey instrument was designed, verified, and distributed globally to the veterinary echocardiographers. RESULTS: A total of 670 echocardiographers from 54 countries on six continents completed the survey. Most echocardiographers (n = 621) used linear two-dimensional (2D)-based methods to assess LA size, 379 used subjective assessment, and 151 used M-mode-based methods. Most commonly, echocardiographers combined linear 2D-based methods with subjective assessment (n = 222), whereas 191 used linear 2D-based methods alone. Most echocardiographers (n = 436) using linear 2D-based methods preferred the right parasternal short-axis view and indexed the LA to the aorta. Approximately 30% (n = 191) of the echocardiographers who performed linear measurements from 2D echocardiograms shared the same preferences regarding dog position, acquisition view, indexing method, and identification of the time-point used for the measurement. The responses were comparably homogeneous across geographic location, training level, years of performing echocardiography, and type of practice. DISCUSSION/CONCLUSION: Most veterinary echocardiographers assessed LA size in dogs using linear 2D echocardiography from a right parasternal short-axis view, and by indexing the LA to the aorta. The respondents' preferences were similar across geographic, demographic, and professional backgrounds.

Use of physical examination, electrocardiography, radiography, and biomarkers to predict echocardiographic stage B2 myxomatous mitral valve disease in preclinical Cavalier King Charles Spaniels.

INTRODUCTION: Cavalier King Charles Spaniels (CKCS) are predisposed to developing myxomatous mitral valve disease (MMVD). Dogs with stage B2 MMVD benefit from medication. OBJECTIVES: To develop (1) breed-specific cut-offs for individual screening tests and (2) predictive models utilizing physical examination (PE), ECG, radiograph, and blood-based biomarker variables in combination for identification of echocardiographic stage B2 MMVD in preclinical CKCS. ANIMALS: Adult, preclinical CKCS not receiving cardiac medications (N = 226). MATERIALS AND METHODS: Prospective, cross-sectional study. Enrolled CKCS underwent PE, ECG, radiography, Doppler blood pressure measurement, echocardiography, and biomarker testing. Dogs were grouped by MMVD stage using echocardiography only. The discriminatory ability of individual tests to identify stage B2 was assessed, and prediction models were developed using variables derived from four 'tests' (PE, ECG, radiography, and biomarkers). RESULTS: N-terminal pro-B-type natriuretic peptide (NT-proBNP) and radiographic vertebral heart size (VHS) had the best discriminatory ability of individual diagnostic tests to differentiate stage A/B1 CKCS from stage B2, with an area under the curve (AUC) of 0.855 and 0.843, respectively. An NT-proBNP ≥1138 pmol/L or a VHS ≥11.5 had high specificity for predicting stage B2 (90.1% and 90.6%, respectively). Prediction models incorporating variables from multiple tests had better discriminatory ability than single tests. The four-test prediction model had an AUC of 0.971. Three and two-test models had AUCs ranging between 0.925-0.959 and 0.895-0.949, respectively. CONCLUSIONS: Both NT-proBNP and VHS have good utility for predicting echocardiographic stage B2 MMVD in CKCS as individual tests. Prediction models incorporating multiple test variables have superior discriminatory ability.

Impact of blood tube additives and timing of sampling on blood taurine concentrations in clinically healthy dogs.

INTRODUCTION: Dilated cardiomyopathy can be associated with taurine deficiency in dogs. Blood taurine concentrations can be analyzed in whole blood (WB) and plasma. The study objectives were to investigate agreement between taurine concentrations measured in WB, heparin plasma, and EDTA plasma, determine intraindividual variation in healthy dogs, and evaluate if time from feeding to sampling impacts concentrations. ANIMALS: Ten English Cocker spaniels and 10 dogs of various breeds. MATERIALS AND METHODS: Dogs were fasted 12 h prior to initial blood sampling, and the blood was collected at five occasions over eight h. Food was offered immediately after first and one h after fourth sampling time point. RESULTS: Agreement between taurine concentrations in EDTA plasma and heparinized plasma was good (mean difference 4.5 nmol/mL, 95% confidence interval (CI) 36.8-45.8 nmol/mL). Whole blood concentrations were systematically higher than EDTA and heparin plasma concentrations (mean difference 132.7 nmol/mL, 95% CI 23.6-241.8 nmol/mL, and 127.6 nmol/mL, 95% CI 28.6-226.6 nmol/mL, respectively, all P < 0.001). Intraindividual daily variations in taurine concentration were seen in all additives, with largest variations in plasma (P < 0.001). Taurine concentration in heparinized plasma was higher at first and fifth sampling time points compared to the fourth (P = 0.014). DISCUSSION: Agreement was found between taurine concentrations measured in different additives, with expected higher concentration in WB than plasma. Taurine concentrations measured in heparinized plasma varied with sampling time point. Intraindividual daily variations were observed in all additives, but mainly in plasma samples. CONCLUSION: Taurine concentrations in dogs with suspected deficiency should be interpreted with caution.

The longitudinal outcome of canine (K9) myxomatous mitral valve disease (LOOK-Mitral) registry: Baseline treatment characteristics.

OBJECTIVES: To describe the medical treatment prescribed or modified by veterinary cardiologists at the enrollment visit in dogs included in the longitudinal outcome of canine (K9) myxomatous mitral valve disease (MMVD) registry (LOOK-mitral registry) and to evaluate the influence of the EPIC trial and other selected variables on cardiologist prescription habits. ANIMALS: The medical records of 6,102 dogs enrolled in the LOOK_mitral registry between 2015 and 2018 were retrospectively reviewed and 6,016 dogs were included. RESULTS: A medical treatment was prescribed by a cardiologist to 2,599 dogs (15% Stage-B1, 90% Stage-B2 and to all dogs in Stage-C). Angiotensin converting enzyme inhibitors (Ace-i) were the treatment most commonly prescribed for dogs in Stage-B1 (n = 352, 9%). The combination of pimobendan and an Ace-i was the most common treatment in Stage-B2 dogs (n = 367, 41%). Furosemide, an Ace-i, and pimobendan was the most common cardiac medical treatment prescribed for ACVIM Stage-C dogs (n = 704, 57%). Within each stage, dogs with larger left atrial and left ventricular dimensions were more likely to receive Ace-i, pimobendan or spironolactone. There was a four-fold increase in pimobendan prescription in Stage-B2 dogs after the publication of the EPIC trial. Moreover, a 15% reduction in Ace-i prescription and a 30% reduction in spironolactone prescription occurred after EPIC. In 974 dogs, a medical treatment was prescribed by the referring veterinarian. This was not changed (12%), modified (74%), or discontinued (14%) by the cardiologist. CONCLUSIONS: The EPIC trial and the echocardiographic assessment of left atrial and ventricular dimensions influence cardiologists' prescription habits.

Prospective evaluation of the combined value of physical examination and biomarker variables in screening for preclinical dilated cardiomyopathy in Doberman Pinschers.

INTRODUCTION: Screening to assess likelihood of preclinical dilated cardiomyopathy (PC-DCM) prior to advanced diagnostic tests in Doberman Pinschers (DP) is desirable. OBJECTIVE: To investigate the combined value of physical examination (PE), N-terminal pro B-type natriuretic peptide (NTproBNP) and cardiac troponin I (cTnI) for identifying PC-DCM in DP. ANIMALS, MATERIALS AND METHODS: All dogs underwent: PE, echocardiogram, 3-min ECG and cardiac biomarker measurement. Asymptomatic DP (414) were classified based on 3-min ECG and echocardiogram as: No-DCM/MMVD or myxomatous mitral valve disease (MMVD), PC-DCM based on echocardiogram (PC-DCM-Echo), PC-DCM based on arrhythmias with a normal echocardiogram (PC-DCM-ECG), equivocal DCM (EQ-DCM), and MMVD. Receiver operator characteristic curves and prediction models were derived. RESULTS: Heart murmurs and arrhythmias were rare and gallop sounds were absent in No-DCM/MMVD DP. Dogs ≥ four years old and males had higher probabilities of PC-DCM-Echo. Prediction models incorporating PE variables with NTproBNP had an area under the curve (AUC) of 0.940 for distinguishing between PC-DCM-Echo and all other groups, which was similar to the AUC for NTproBNP (0.939) or cTnI (0.932) alone. Discrimination between No-DCM/MMVD and all other groups was similar for NTproBNP (0.781) and cTnI (0.742) as individual tests, however, models combining PE variables and NTproBNP increased the AUC to 0.812. An NTproBNP cut-off of ≥548 pmol/L, was 100% sensitive and 77.3% specific for detecting PC-DCM-Echo. CONCLUSIONS: Both NTproBNP and cTnI had good utility as sole tests to discriminate PC-DCM-Echo DP from all others. Models differentiating No-DCM/MMVD DP from all other DP were improved by using PE and NTproBNP together.

Prognostic value of selected one-, two- and three-dimensional and Doppler echocardiographic methods to assess severity in dogs with myxomatous mitral valve disease.

INTRODUCTION: Although challenging, predicting outcomes in dogs with myxomatous mitral valve disease (MMVD) is of importance to owners and veterinarians. Our aim was to compare the prognostic value of selected one-, two-, and three-dimensional and Doppler echocardiographic methods to predict cardiac-related and all-cause mortality in MMVD dogs. We hypothesize that three-dimensional methods would better predict prognosis than one- and two-dimensional methods. ANIMALS: One-hundred thirty-eight privately-owned dogs with MMVD. MATERIALS AND METHODS: Cox proportional Hazard analyses and Kaplan-Meier curves were used to investigate the predictive value of 14 variables; left atrial (LA) volume indexed to body weight (BW) measured by real-time three-dimensional echocardiography (RT3DE) and calculated using Simpson's modified method of discs (SMOD) and the area-length method; LA diameter in short-axis and long-axis to aortic in short-axis ratio, effective regurgitant orifice area indexed to body surface area measured in RT3DE en face view and calculated using four-chamber (4Ch) and two-chamber views alone or in combination; percentage increase in left ventricular end-diastolic and systolic internal diameters; fractional shortening; E wave velocity; regurgitant jet area/LA area. RESULTS: All 14 variables were significantly predictive of cardiac-related mortality, and 11 were predictive of all-cause mortality. The prognosis was best predicted by LA volume/BW estimated by SMOD or RT3DE, consistently showing the highest predictive value in all analyses. CONCLUSIONS: Left atrial volume calculated by SMOD showed a similar predictive value compared to RT3DE. Performing SMOD from apical 4Ch images should be considered an alternative to RT3DE for echocardiographic examinations where prognostication of disease outcome is sought.

Prediction of clinically important acquired cardiac disease without an echocardiogram in large breed dogs using a combination of clinical, radiographic and electrocardiographic variables.

INTRODUCTION: Large breed (LB) dogs develop dilated cardiomyopathy (DCM) and myxomatous mitral valve disease (MMVD). Echocardiography is required for a definitive diagnosis but is not always available. Our objective was to assess the clinical utility of thoracic radiographs alone and in combination with physical examination and electrocardiography findings for the prediction of clinically important DCM or MMVD in LB dogs. ANIMALS: Four hundred fifty-five client-owned dogs ≥20 kg with concurrent thoracic radiographs and echocardiogram. MATERIALS AND METHODS: Medical records were reviewed and stored thoracic radiographs and echocardiographic images were measured to classify dogs as normal heart size (NHS), preclinical DCM, clinical DCM, preclinical MMVD (with cardiomegaly), clinical MMVD, or equivocal. Dogs with preclinical MMVD, without cardiomegaly, were classified as NHS. Vertebral heart size (VHS) and vertebral left atrial size (VLAS) were measured. Receiver operating characteristic curves and prediction models were derived. RESULTS: Prevalence of MMVD (39.3%) was higher than the prevalence of DCM (24.8%), though most MMVD dogs (67.0%) lacked cardiomegaly and were classified as NHS for analysis. The area under the curve for VHS to discriminate between NHS and clinical DCM/MMVD or preclinical DCM/MMVD was 0.861 and 0.712, respectively, while for VLAS, it was 0.891 and 0.722, respectively. Predictive models incorporating physical examination and electrocardiography findings in addition to VHS/VLAS increased area under the curve to 0.978 (NHS vs. clinical DCM/MMVD) and 0.829 (NHS vs. preclinical DCM/MMVD). CONCLUSIONS: Thoracic radiographs were useful for predicting clinically important DCM or MMVD in LB dogs, with improved discriminatory ability when physical examination abnormalities and arrhythmias were accounted for.

Permanent stoma rates after anterior resection for rectal cancer: risk prediction scoring using preoperative variables.

BACKGROUND: A permanent stoma after anterior resection for rectal cancer is common. Preoperative counselling could be improved by providing individualized accurate prediction modelling. METHODS: Patients who underwent anterior resection between 2007 and 2015 were identified from the Swedish Colorectal Cancer Registry. National Patient Registry data were added to determine presence of a stoma 2 years after surgery. A training set based on the years 2007-2013 was employed in an ensemble of prediction models. Judged by the area under the receiving operating characteristic curve (AUROC), data from the years 2014-2015 were used to evaluate the predictive ability of all models. The best performing model was subsequently implemented in typical clinical scenarios and in an online calculator to predict the permanent stoma risk. RESULTS: Patients in the training set (n = 3512) and the test set (n = 1136) had similar permanent stoma rates (13.6 and 15.2 per cent). The logistic regression model with a forward/backward procedure was the most parsimonious among several similarly performing models (AUROC 0.67, 95 per cent c.i. 0.63 to 0.72). Key predictors included co-morbidity, local tumour category, presence of metastasis, neoadjuvant therapy, defunctioning stoma use, tumour height, and hospital volume; the interaction between age and metastasis was also predictive. CONCLUSION: Using routinely available preoperative data, the stoma outcome at 2 years after anterior resection for rectal cancer can be predicted fairly accurately.

Usually, the goal of rectal cancer surgery is to remove the tumour and construct a bowel join. Sometimes, it is necessary to construct a stoma, which may become permanent. Swedish registry data were used to develop and test a statistical model to forecast the risk of a stoma 2 years after surgery. In addition, an online calculator was developed. The model performed reasonably well, and can be used to inform the patient and surgeon before surgery of the risk of a permanent stoma.

The Longitudinal Outcome Of Canine (K9) myxomatous mitral valve disease (LOOK-Mitral registry): Baseline characteristics.

INTRODUCTION: The Longitudinal Outcome Of Canine (K9) myxomatous mitral valve disease (MMVD) registry (LOOK-Mitral registry) was established to describe the natural history and predictors of outcome in dogs affected by MMVD. This study was intended to describe the baseline characteristics of dogs in the LOOK-mitral registry. ANIMALS: Dogs with echocardiographic evidence of MMVD were prospectively enrolled by thirteen referral centers. RESULTS: A total of 6102 dogs with MMVD were included. The median age was 10 years (1-19 years), and mixed breed was the most common breed (n = 1,360, 22%). Concomitant diseases were reported in 2459 dogs with chronic respiratory diseases occurring most frequently (14%), followed by the presence of azotemia (6%) and orthopedic diseases (5%). Regarding disease severity, 65% of dogs were in ACVIM Stage-B1, 15% in Stage-B2, and 20% in Stage-C. Dogs in Stage-B1 were younger (p<0.001) than dogs in other stages. Murmur intensity, heart rate during physical examination, and radiographic vertebral heart score were positively associated with the stage. Dogs in Stage-C were more likely to have tachypnea (p<0.001), dyspnea (p<0.001), cough (p<0.001), syncopal episodes (p<0.001), and tachyarrhythmias (p<0.001) compared to dogs in Stage-B1 and B2. Echocardiographic indices of left atrial and ventricular size were positively correlated with the ACVIM stage. Interestingly, 4% of dogs that weighed <20 kg had an increased normalized end-systolic left ventricle internal diameter (>1.26). CONCLUSIONS: This study contributes to a better understanding of the clinical characteristics of dogs affected by MMVD and provides new findings that may be of clinical relevance.

Predictors of reoccurrence of congestive signs within 180 days after successful treatment of the first episode of congestive heart failure in dogs with myxomatous mitral valve disease.

INTRODUCTION: Myxomatous mitral valve disease (MMVD) is the most common cause of left-sided congestive heart failure in dogs. We sought to identify predictors of first reoccurrence of congestive signs (CS) within 180 days in dogs with MMVD and clinically stable heart failure. ANIMALS: A total of 445 dogs affected by stable American College of Veterinary Internal Medicine (ACVIM)-Stage-C MMVD were included, 106 in the reoccurrence group (RG) and 339 in no reoccurrence group (NRG). Patients were considered "stable" if medical treatment had been unchanged for at least 4 weeks since the first identification of CS. METHODS: Medical records of dogs with stable ACVIM-Stage-C MMVD included in a registry of dogs affected by MMVD were reviewed. Follow-up was required for inclusion in this investigation. Logistic regression was used to identify clinical and echocardiographic variables that independently predict first reoccurrence of CS. RESULTS: Baseline left atrial-aortic ratio (p=0.022, OR: 1.89, 90% CI: 1.20-2.98), left ventricular internal diameter at end-diastole (LVIDd_N) (p=0.014, OR: 2.84, 90% CI: 1.41-5.77), peak velocity of early diastolic transmitral flow (p=0.049, OR: 1.81, 90% CI: 1.10-3.00) and furosemide daily dosage (p=0.039, OR: 1.19, 90% CI: 1.04-1.37) were associated with reoccurrence of CS in univariable analyses. The LVIDd_N (p=0.014) remained significant in the multivariable analysis, but the area under the receiver operator characteristic curve was 0.57. CONCLUSION: This study failed to identify accurate predictors of reoccurrence of CS. However, dogs with larger value of LVIDd_N are more likely to have reoccurrence of CS within 180 days.

Intermittent mitral regurgitation in Cavalier King Charles spaniels: Short-term progression and influence of stress tests.

In young Cavalier King Charles spaniels (CKCS), intermittent mitral regurgitation (iMR; defined as moderate to severe mitral regurgitation [MR] in a small proportion of heartbeats), has been associated with an increased risk of cardiac death due to myxomatous mitral valve disease (MMVD). It is associated with increased R-R interval variability. Little is known about response to physiological factors and whether iMR is a precursor for developing significant MR. The aim of this study was to determine the effect of stress testing on the presence of iMR and heart rate, and short-term (1-2 year) progression of MR in CKCS with and without iMR. In total, 52 CKCS were included. Substudy 1 enrolled six dogs with iMR and 11 dogs without iMR. Substudy 2 enrolled 14 dogs with iMR and 28 dogs without iMR. Substudy 1 prospectively assessed the influence of stress testing on the presence of iMR and heart rate. Substudy 2 retrospectively evaluated short-term progression of iMR. During stress testing, iMR disappeared in 50% of CKCS and no iMR was recorded at mean heart rates >150 beats/min. Heart rate response did not differ between CKCS with or without iMR. CKCS with iMR did not have a higher odds (odds ratio = 5.2; 95% confidence interval, 0.7-38.2) of MR progression compared to controls (P = 0.1). In conclusion, physical stress influenced the occurrence of iMR in CKCS, but heart rate response was not different from CKCS without iMR. Intermittent mitral regurgitation did not significantly predict short-term MR progression. In stressed CKCS with early disease, iMR may be overlooked.

Urine 5-hydroxyindoleacetic acid in Cavalier King Charles spaniels with preclinical myxomatous mitral valve disease.

Higher concentrations of circulating serotonin have been reported in Cavalier King Charles spaniels (CKCS) compared to other dog breeds. The CKCS is also a breed highly predisposed to myxomatous mitral valve disease (MMVD). The aim of this study was to determine urine concentrations of 5-hydroxyindoleacetic acid (5-HIAA), the major metabolite and excretion product of serotonin, in a population of CKCS with preclinical MMVD, and to evaluate whether urine 5-HIAA concentrations were associated with MMVD severity, dog characteristics, setting for urine sampling, platelet count, and serotonin concentration in serum and platelet-poor plasma (PPP). The study population consisted of 40 privately-owned CKCS (23 females; 17 males) with and without preclinical MMVD as follows: American College of Veterinary Internal Medicine (ACVIM) group A (n = 11), ACVIM group B1 (n = 21) and ACVIM group B2 (n = 8). Urine 5-HIAA concentrations were not significantly associated with preclinical MMVD disease, platelet count or circulating concentrations of serotonin (in serum and PPP; P > 0.05). Females had higher 5-HIAA concentrations than males in morning urine collected at home (females, 3.1 [2.9-3.7] µmol/mmol creatinine [median and quartiles]; males, 1.7 [1.2-2.2] µmol/mmol creatinine; P = 0.0002) and urine collected at the clinic (females, 3.5 [3.1-3.9] µmol/mmol creatinine; males, 1.6 [1.3-2.1] µmol/mmol creatinine; P < 0.0001). Five-HIAA concentrations in urine collected at home and at the clinic were significantly associated (P = 0.0004; r = 0.73), and higher concentrations were found in urine collected at the clinic (P = 0.013). Urine 5-HIAA concentration was influenced by sex and setting of urine sampling. Urine 5-HIAA concentration was not associated with MMVD severity or circulating concentrations of serotonin in CKCS with preclinical disease.

Urinary peptidome analyses for the diagnosis of chronic kidney disease in dogs.

Chronic kidney disease (CKD) is clinically important in canine medicine. Current diagnostic tools lack sensitivity for detection of subclinical CKD. The aim of the present study was to evaluate urinary peptidome analysis for diagnosis of CKD in dogs. Capillary electrophoresis coupled to mass spectrometry analysis demonstrated presence of approximately 5400 peptides in dog urine. Comparison of urinary peptide abundance of dogs with and without CKD led to the identification of 133 differentially excreted peptides (adjusted P for each peptide <0.05). Sequence information was obtained for 35 of these peptides. This 35 peptide subset and the total group of 133 peptides were used to construct two predictive models of CKD which were subsequently validated by researchers masked to results in an independent cohort of 20 dogs. Both models diagnosed CKD with an area under the receiver operating characteristic (ROC) curve of 0.88 (95% confidence intervals [CI], 0.72-1.0). Most differentially excreted peptides represented fragments of collagen I, indicating possible association with fibrotic processes in CKD (similar to the equivalent human urinary peptide CKD model, CKD273). This first study of the urinary peptidome in dogs identified peptides that were associated with presence of CKD. Future studies are needed to validate the utility of this model for diagnosis and prediction of progression of canine CKD in a clinical setting.

Breed-specific reference ranges for standard echocardiographic measurements in salukis.

OBJECTIVES: To establish normal reference ranges for standard echocardiographic measurements in Salukis and to examine whether bodyweight, age, gender and heart rate had an influence on the echocardiographic variables. MATERIALS AND METHODS: Seventy-five privately owned healthy purebred Salukis, aged 2 to 10 years were included. Case history was obtained and dogs were examined by physical examination, complete blood cell count, serum biochemistry and echocardiography. Associations between bodyweight, gender, sex and heart rate and echocardiographic variables were examined using multiple linear regression analysis and allometric scaling. Reference values with 95% prediction intervals were calculated from regression equations. RESULTS: Bodyweight was a significant predictor of left ventricular diameters, left ventricular volumes and E-point-to-septal-separation. Associations between bodyweight and the echocardiographic variables were best described by multiple linear regression models, providing bodyweight-based reference values. Age, gender and heart rate had significant effect on some of the echocardiographic variables and were included in the final models. When the equation included heart rate or age, reference values were calculated using mean heart rate value (80 bpm) and median age value (73 months). CLINICAL SIGNIFICANCE: This study provides detailed bodyweight-based echocardiographic values in normal Salukis which can be used as reference values.

Presence of thoracic and lumbar vertebral malformations in pugs with and without chronic neurological deficits.

Congenital vertebral malformations (CVMs) are common in brachycephalic dogs such as the pug, and are often considered incidental findings. However, specific CVMs have been suggested to be associated with neurological deficits in pugs. The objective of this study was to investigate the clinical importance of CVMs in the pug by comparing computed tomography studies of the thoracolumbar spine from pugs without neurological deficits with those from pugs with a confirmed T3-L3 spinal cord lesion and neurological deficits consistent with a chronic T3-L3 myelopathy. A total of 57 pugs were recruited into the study from Sweden (n=33), United Kingdom (n=21) and Norway (n=3); 30 with neurological deficits and 27 without. Focal T3-L3 pathology was confirmed in all pugs with neurological deficits by magnetic resonance imaging (n=29) and/or pathology (n=15). Computed tomography studies of the thoracolumbar spine from pugs with and without neurological deficits were compared to investigate possible associations between presentation of neurological deficits consistent with chronic T3-L3 pathology and signalment variables, presence of CVMs and type of CVMs. Congenital vertebral malformations were as common in pugs with, as in pugs without, neurological deficits. Regardless of neurological status, the majority of pugs (96%) presented with one or more CVM. An association between presence, or type of CVM in the T1-L3 vertebral column, and neurological deficits consistent with T3-L3 pathology could not be confirmed.

Interbreed variation in serum serotonin (5-hydroxytryptamine) concentration in healthy dogs.

INTRODUCTION: Serotonin (5-hydroxytryptamine [5-HT]) has several biological functions. In different species, excessive 5-HT has been linked to valvular lesions, similar to those seen in dogs with myxomatous mitral valve disease. Previous studies suggest higher 5-HT in healthy Cavalier King Charles Spaniels (CKCSs), a breed highly affected by myxomatous mitral valve disease, compared to other breeds. OBJECTIVE: To investigate potential interbreed variation in serum 5-HT in healthy dogs. ANIMALS: 483 healthy dogs of nine breeds aged 1-7 years. METHODS: Dogs were examined at five European centers. Absence of cardiovascular, organ-related, or systemic diseases was ensured by thorough clinical investigations including echocardiography. Serum was frozen and later analyzed by enzyme-linked immunosorbent assay (ELISA). RESULTS: Median 5-HT concentration was 252.5 (interquartile range = 145.5-390.6) ng/mL. Overall breed difference was found (p<0.0001), and 42% of pairwise breed comparisons were significant. Univariate regression analysis showed association between serum 5-HT concentration and breed, center of examination, storage time, and sex, with higher 5-HT in females. In multiple regression analysis, the final model had an adjusted R2 of 0.27 with breed (p<0.0001), center (p<0.0001), and storage time (p=0.014) remaining significant. Within centers, overall breed differences were found at 3/5 centers (p≤0.028), and pairwise comparisons within those centers showed breed differences in 42% of comparisons. Among the included breeds, Newfoundlands, Belgian Shepherds and CKCSs had highest 5-HT concentrations. CONCLUSIONS: Interbreed variation in serum 5-HT concentration was found in healthy dogs aged 1-7 years. These differences should be taken into account when designing clinical studies.

Longitudinal Analysis of Quality of Life, Clinical, Radiographic, Echocardiographic, and Laboratory Variables in Dogs with Preclinical Myxomatous Mitral Valve Disease Receiving Pimobendan or Placebo: The EPIC Study.

BACKGROUND: Changes in clinical variables associated with the administration of pimobendan to dogs with preclinical myxomatous mitral valve disease (MMVD) and cardiomegaly have not been described. OBJECTIVES: To investigate the effect of pimobendan on clinical variables and the relationship between a change in heart size and the time to congestive heart failure (CHF) or cardiac-related death (CRD) in dogs with MMVD and cardiomegaly. To determine whether pimobendan-treated dogs differ from dogs receiving placebo at onset of CHF. ANIMALS: Three hundred and fifty-four dogs with MMVD and cardiomegaly. MATERIALS AND METHODS: Prospective, blinded study with dogs randomized (ratio 1:1) to pimobendan (0.4-0.6 mg/kg/d) or placebo. Clinical, laboratory, and heart-size variables in both groups were measured and compared at different time points (day 35 and onset of CHF) and over the study duration. Relationships between short-term changes in echocardiographic variables and time to CHF or CRD were explored. RESULTS: At day 35, heart size had reduced in the pimobendan group: median change in (Δ) LVIDDN -0.06 (IQR: -0.15 to +0.02), P < 0.0001, and LA:Ao -0.08 (IQR: -0.23 to +0.03), P < 0.0001. Reduction in heart size was associated with increased time to CHF or CRD. Hazard ratio for a 0.1 increase in ΔLVIDDN was 1.26, P = 0.0003. Hazard ratio for a 0.1 increase in ΔLA:Ao was 1.14, P = 0.0002. At onset of CHF, groups were similar. CONCLUSIONS AND CLINICAL IMPORTANCE: Pimobendan treatment reduces heart size. Reduced heart size is associated with improved outcome. At the onset of CHF, dogs treated with pimobendan were indistinguishable from those receiving placebo.

European Society of Veterinary Cardiology screening guidelines for dilated cardiomyopathy in Doberman Pinschers.

BACKGROUND: Dilated cardiomyopathy (DCM) is the most common cardiac disease in large breed dogs and is inherited in Doberman Pinschers with a high prevalence (58%). OBJECTIVE: The European Society for Veterinary Cardiology convened a task force to formulate screening guidelines for DCM in Dobermans. RECOMMENDATIONS: Screening for occult DCM in Dobermans should start at three years of age and use both Holter monitoring and echocardiography. Yearly screening over the life of the dog is recommended, as a one-time screening is not sufficient to rule out future development of DCM. The preferred echocardiographic method is the measurement of the left ventricular volume by Simpson's method of discs (SMOD). Less than 50 single ventricular premature complexes (VPCs) in 24 h are considered to be normal in Dobermans, although detection of any number of VPCs is cause for concern. Greater than 300 VPCs in 24 h or two subsequent recordings within a year showing between 50 and 300 VPCs in 24 h is considered diagnostic of occult DCM in Dobermans regardless of the concurrent echocardiographic findings. The guidelines also provide recommendations concerning ancillary tests, that are not included in the standard screening protocol, but which may have some utility when recommended tests are not available or financially untenable on an annual basis. These tests include assay of cardiac biomarkers (Troponin I and N-Terminal pro-B-type Natriuretic Peptide) as well as a 5-min resting electrocardiogram (ECG). CONCLUSION: The current guidelines should help to establish an early diagnosis of DCM in Dobermans.

Mitral Regurgitation Severity and Left Ventricular Systolic Dimension Predict Survival in Young Cavalier King Charles Spaniels.

BACKGROUND: Development and progression of myxomatous mitral valve disease (MMVD) in dogs are difficult to predict. Identification at a young age of dogs at high risk of adverse outcome in the future is desirable. HYPOTHESIS/OBJECTIVES: To study the predictive value of selected clinical and echocardiographic characteristics associated with MMVD obtained at a young age for prediction of long-term cardiac and all-cause mortality in Cavalier King Charles Spaniels (CKCS). ANIMALS: 1125 privately owned CKCS. METHODS: A retrospective study including CKCS examined at the age of 1-3 years. Long-term outcome was assessed by telephone interview with owners. The value of variables for predicting mortality was investigated by Cox proportional hazard and Kaplan-Meier analyses. RESULTS: Presence of moderate to severe mitral regurgitation (MR) (hazard ratio (HR) = 3.03, 95% confidence interval (95% CI) = 1.48-6.23, P = 0.0025) even intermittent moderate to severe MR (HR = 2.23, 95% CI = 1.48-6.23, P = 0.039) on color flow Doppler echocardiography was significantly associated with increased hazard of cardiac death. An interaction between MR and sex was significant for all-cause mortality (P = 0.035), showing that males with moderate to severe MR had a higher all-cause mortality compared to males with no MR (HR = 2.38, 95% CI = 1.27-4.49, P = 0.0071), whereas no difference was found between female MR groups. The risk of cardiac (HR = 1.37, 95% CI = 1.14-1.63, P < 0.001) and all-cause (HR = 1.13, 95% CI = 1.02-1.24, P = 0.016) mortality increased with increasing left ventricular end-systolic internal dimension normalized for body weight (LVIDSN ). CONCLUSIONS AND CLINICAL IMPORTANCE: Moderate to severe MR, even if intermittent, and increased LVIDSN in dogs <3 years of age were associated with cardiac death later in life in CKCS.