Top-down effects of raptor predation on northern bobwhite.

Understanding how predators affect prey species is a central endeavor in applied ecology. Game birds are a culturally and economically important group of birds throughout the world. Specifically, northern bobwhite (Colinus virginianus) is an imperiled game bird native to North America that has declined precipitously over the past 65 years. Concurrently, raptor populations increased substantially as a result of pesticide bans and legal protections. However, relationships between raptors and bobwhites are not well-understood because of limited long-term data. We analyzed long-term raptor survey and bobwhite survival datasets from 2008 to 2018 to determine if oscillations in raptor abundance affected bobwhite survival. We used a novel open multi-species dynamics hierarchical distance sampling model to estimate the abundance of raptors. We used a known-fate survival model to determine if variation in raptor abundance affected bobwhite survival. We had multiple working hypotheses regarding biological relationships between raptor abundance and bobwhite survival. Raptors affected bobwhites in every biological season but were more influential in the breeding season and late winter supporting the notion of bobwhite behavior and raptor migration were driving observed patterns. Our results suggest that even in areas with abundant habitat, predators exert top-down influences on vital rates suggesting similar or greater influences on populations under poor habitat conditions.

Evaluation of the NuCLEUS-X™ balloon valvuloplasty catheter for severe pulmonic stenosis in dogs.

INTRODUCTION/OBJECTIVES: Balloon instability is commonly encountered during balloon pulmonary valvuloplasty (BPV) and may result in an unsuccessful procedure. The NuCLEUS-X™ catheter is a recently developed BPV catheter with a unique barbell shape and an ordered pattern of inflation that stabilizes the balloon to span the valve annulus before expansion of the balloon center. ANIMALS: Ten client-owned dogs with severe valvular pulmonic stenosis (PS). MATERIALS AND METHODS: Prospective observational study. The BPV procedure was performed by standard technique with use of NuCLEUS-X™ catheters targeting a balloon-to-annulus ratio between 1.2 and 1.5. Balloon stability, safety, and procedural success were assessed. Procedural success was defined as either a reduction in the Doppler transpulmonic PG by at least 50% of the pre-procedural PG or <80 mmHg one month post procedure. RESULTS: Balloon stability centered at the pulmonic valve on the first inflation was achieved in 10/10 cases. The mean PG before BPV was 141 mmHg ±41 mmHg, and the PG after BPV at one month was 83 mmHg ±41 mmHg. Procedural success was achieved in 56% of patients. All dogs survived the BPV, and no major procedural complications were encountered using the NuCLEUS-X™ catheter. CONCLUSIONS: The use of the NuCLEUS-X™ catheter is feasible for BPV in dogs with severe PS. The unique balloon shape provided catheter stability on the first inflation in all dogs, which may be beneficial when stabilization of a conventional BPV catheter cannot be achieved.

Prevalence of major complications and procedural mortality in 336 dogs undergoing interventional cardiology procedures in a single academic center.

INTRODUCTION: Overall complication rates associated with a wide range of diagnostic and therapeutic interventional cardiac procedures in a contemporary academic setting have not been reported. ANIMALS, MATERIALS AND METHODS: Consecutive interventional procedures performed for client-owned dogs were retrospectively analyzed to characterize procedural complications and mortality. RESULTS: Three hundred sixty-four procedures were performed on 336 dogs. Interventions included attempted or completed transvenous pacemaker (PM) implantation (n = 134) with subsequent pacing system revision (n = 8), pulmonic balloon valvuloplasty (BVP) (n = 117) with a subset of patients undergoing an additional BVP (n = 14), transarterial closure of left-to-right shunting patent ductus arteriosus (PDA) (n = 66), diagnostic angiography and/or cardiovascular pressure measurement (n = 9), transvenous temporary pacing (n = 7), septal defect occlusion (n = 5), heartworm extraction (n = 3), and BVP catheter fragment retrieval (n = 1). The prevalence of major perioperative and postoperative complications for all procedures was 5% and 6%, respectively, and the procedural mortality rate was 2%. The overall rate of major complications was 12% for the PM group, 11% for the BVP group, and 2% for the PDA occlusion group. Both PM implantation and BVP have higher rates of major complications overall compared with PDA occlusion (p=0.0151). CONCLUSIONS: The results of this study indicate that the prevalence of major complications and mortality associated with interventional cardiac procedures is low; however, significant differences exist in complication rates between procedures.

Assessment of left ventricular volume and function in healthy dogs by use of one-, two-, and three-dimensional echocardiography versus multidetector computed tomography.

OBJECTIVE To compare left ventricle (LV) volume and function variables obtained by use of 1-D, 2-D, and real-time 3-D echocardiography versus ECG-gated multidetector row CT (MDCT) angiography, which was considered the criterion-referenced standard. ANIMALS 6 healthy, purpose-bred dogs. PROCEDURES Dogs were anesthetized and administered a constant rate infusion of esmolol, and 1-D, 2-D, and 3-D echocardiography and ECG-gated, contrast-enhanced MDCT were performed. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume, and ejection fraction (EF) were calculated by use of the Teichholz method for 1-D echocardiography, single-plane and biplane modified Simpson method of disks (MOD) and area-length method for 2-D echocardiography, and real-time biplane echocardiography (RTBPE) and real-time 3-D echocardiography (RT3DE) for 3-D echocardiography. Volumes were indexed to body surface area and body weight. Median values, correlations, and limits of agreement were compared between echocardiographic modalities and MDCT. RESULTS EDV and ESV measured by use of RTBPE and RT3DE had the strongest correlations with results for MDCT. Values obtained for EDV, ESV, stroke volume, and EF did not differ significantly between echocardiographic methods and MDCT. Use of RT3DE and RTBPE slightly underestimated EDV, ESV, and EF, compared with values for MDCT, as determined with Bland-Altman analysis. CONCLUSIONS AND CLINICAL RELEVANCE Values for EDV and ESV obtained by use of 3-D echocardiography, including RTBPE and RT3DE, had the highest correlation with slight underestimation, compared with values obtained by use of MDCT. This was similar to results for 3-D echocardiography in human medicine.

Quantitative evaluation of left atrial volume and function by one-dimensional, two-dimensional, and three-dimensional echocardiography in a population of normal dogs.

OBJECTIVES: The primary goal of this study was to compare left atrial (LA) volume and functional indices in a population of normal dogs using transthoracic one-dimensional M-mode, two-dimensional (2D), and three-dimensional (3D) echocardiography. ANIMALS: Forty clinically normal dogs of various breeds were stratified into four groups based on weight. METHODS: Left atrial volume (LAV) was estimated by converting single linear measurements derived from M-mode and 2D images into volumes via the cube and sphere formulas. 2D echocardiography was employed to estimate LAV using linear measures and rectangular and ellipsoid formulas, as well as area-length and the monoplane method of disks. LAV was estimated using the biplane area-length method on 4- and 2-chamber 2D images. LAV was directly measured using 3D volume data obtained over four consecutive cardiac cycles. LAV estimates were compared amongst methods, correlated to body size, and evaluated for reproducibility. Functional indices derived from these various echocardiographic methods were compared to identify any systematic differences based on imaging modality. LA functional indices included LA ejection fraction (LAEF), total LA emptying volume, passive LA emptying volume/fraction, active LA emptying volume/fraction, and LA expansion index. RESULTS: The M-mode derived estimates of LAV were significantly smaller than all 2D- and 3D-derived LAV (p<0.0001). The left-sided 3D LAV had the highest correlation with body weight (r2 = 0.8806) for all phases of the LA cycle with acceptable interobserver variability (CV 11%). CONCLUSIONS: 3D echocardiography is a feasible, non-invasive method to measure LAV in a population of normal dogs.

Complete transposition of the great arteries with double outlet right ventricle in a dog.

A 2-year old intact male Collie dog presented to the cardiology service at Oregon State University for evaluation of cyanosis and suspected congenital cardiac disease. Echocardiography revealed a constellation of cardiac abnormalities including a single large vessel exiting the right ventricle with a diminutive left ventricular outflow tract, a ventricular septal defect, and marked concentric right ventricular hypertrophy with moderate right atrial dilation. Cardiac-gated computed tomography confirmed the previous anomalies in addition to supporting a diagnosis of complete transposition of the great arteries, double outlet right ventricle, and pulmonic hypoplasia with a single coronary ostium. Prominent bronchoesophageal collateral vessels were concurrently identified. Clinically, the dog was stable despite mild cyanosis that worsened with exercise; no intervention was elected at the time. This case report describes a rare combination of congenital cardiac defects and the usefulness of cardiac-gated cross-sectional imaging in the anatomic diagnosis.

Cardiac-gated computed tomography angiography in three alpacas with complex congenital heart disease.

BACKGROUND: The prevalence of congenital heart disease is higher in camelids than in other domestic species and complex defects, often involving the great vessels, are more frequently encountered in llamas and alpacas than in other species. Some of these complex defects can be difficult to accurately characterize via echocardiography, the most commonly used diagnostic imaging technique to evaluate the heart in veterinary patients. Contrast-enhanced, electrocardiogram (ECG)-gated computed tomography (CT) has proven utility for the evaluation of human patients with certain congenital heart defects, including those with conotruncal septation defects and other abnormalities involving the formation of the great vessels. METHODS: Three alpaca crias, 4 days, 5 weeks and 14 months of age were clinically evaluated and subjected to a complete color-flow Doppler echocardiogram and a contrast-enhanced ECG-gated CT. RESULTS: These alpacas exhibited a variety of clinical findings including lethargy, failure to thrive, exercise intolerance, heart murmur, and/or respiratory difficulty. All three crias were subsequently diagnosed with complex cardiac defects including pulmonary atresia with a ventricular septal defect (VSD), a truncus arteriosus with a large VSD, and a double outlet right ventricle with a large VSD and aortic hypoplasia. In each case, the diagnosis was confirmed by postmortem examination. CONCLUSION: Color flow echocardiographic evaluation identified all of the intra-cardiac lesions and associated flow anomalies but contrast-enhanced ECG-gated CT permitted more accurate assessment of the morphology of the extracardiac structures and permitted a more precise determination of the exact nature and anatomy of the great vessels.

Detection by ELISA of C-terminal proBNP in plasma from cats with cardiomyopathy.

The B-type natriuretic peptide prohormone (proBNP) is enzymatically cleaved into an inactive N-terminal peptide and a biologically active C-terminal peptide with many beneficial cardiorenal effects. The purpose of this study was to develop and test in cats with cardiomyopathy an immunoassay to quantify the concentrations of C-terminal proBNP in feline plasma. An anti-canine proBNP monoclonal antibody (UI-1021) was shown to have adequate binding affinity to proBNP 80-106 for use in a solid-phase immunoassay, and by epitope mapping to bind within positions 84-87 of feline proBNP. UI-1021 was paired with an affinity-purified rabbit polyclonal detection antibody to feline proBNP 100-106, in a sandwich ELISA with feline proBNP 80-106 standard. The linearity and analytical range and sensitivity of the assay were confirmed from 1.4 to 85 pmol/L. Spike recovery averaged 106.5% (95% confidence interval 78-135%). Within run and intra-assay coefficients of variation were <12%. A protease inhibitor mixture preserved proBNP 80-106 immunoreactivity for at least 5 days in plasma. Clinical verification of the ELISA was done using plasma from 13 cats with cardiomyopathy, whose C-terminal proBNP concentrations ranged from 1.7 to 78.8 pmol/L vs. <1.4-1.8 pmol/L in plasma from 18 healthy cats. Concentrations were found to be substantially lower than reported N-terminal proBNP concentrations, and similar to those of human heart failure patients where relative C-terminal BNP deficiencies have been proposed as contributory to the progression of the disease.

Biologic variability in NT-proBNP and cardiac troponin-I in healthy dogs and dogs with mitral valve degeneration.

BACKGROUND: The N-terminal fragment of the prohormone B-type natriuretic peptide (NT-proBNP) and cardiac troponin-I are candidate biomarkers for cardiac disease in dogs. The degree of biologic variation in these biomarkers has not previously been reported in healthy dogs or dogs with mitral regurgitation. OBJECTIVES: The purpose of the study was to derive estimates of intrinsic biologic variability and reference change values for NT-proBNP and cardiac troponin-I in healthy dogs and dogs with mitral regurgitation grade IB and II according to the International Small Animal Cardiac Health Council (ISACHC) grading system. METHODS: Plasma and sera were collected weekly for up to 7 weeks from 12 control dogs and 9 dogs with mitral regurgitation. NT-proBNP and troponin-I (C-TnI) concentrations were determined. Indices of biologic variation such as reciprocal index of individuality (r-IoI) and reference change values (RCV) were calculated in both the groups. RESULTS: Individuality was high in control dogs and dogs with grade IB and II mitral valve regurgitation for both C-TnI (r-IoI 1.6 and 2) and NT-proBNP (1.5 and 2.7), while the 2-sided RCV for NT-proBNP was significantly lower in dogs with mitral regurgitation (52.5% vs 99.4%, P<0.01.). CONCLUSIONS: High individuality of these cardiac biomarkers suggests that, following diagnosis, these assays are best interpreted by serial determination in individual canine patients rather than by comparison to a population-based reference interval. The smaller RCV values for dogs with mitral regurgitation suggest that smaller relative changes in NT-proBNP are clinically meaningful in these patients.

Long-term outcome of physiologic VDD pacing versus non-physiologic VVI pacing in dogs with high-grade atrioventricular block.

OBJECTIVE: To compare the long-term outcome associated with physiologic VDD and non-physiologic VVI or VVIR pacing in dogs with high-grade atrioventricular block. ANIMALS: Forty-nine paced dogs with high-grade atrioventricular block were included. METHODS: Retrospective review of medical records, thoracic radiographs and echocardiograms for all dogs. Patient owners and referring veterinarians were contacted for survival times and a satisfaction questionnaire was submitted to the owners. Survival times, complication rates, resolution of clinical signs, and owner satisfaction were compared between the pacing modalities. RESULTS: A single lead VDD pacemaker was implanted in 19 dogs (39%) whereas 30 dogs (61%) were treated with VVI pacing. The median survival time for all dogs post-pacemaker implantation was 24.5 months. Survival time was significantly decreased in dogs that were older at the time of presentation or that presented with ventricular tachycardia or reduced left ventricular fractional shortening. Median survival times after implantation were not significantly different between pacing modalities (P = 0.29). Major complication rates were 11% within the VDD group and 20% within the VVI group and were not significantly different (P = 0.46). Minor complications were significantly higher within the VDD group than within the VVI group (47% versus 7% respectively; P < 0.01) due to a higher number of dogs in the VDD group experiencing transient ventricular premature contractions in the immediate post-implantation time period. Resolution of clinical signs, owner satisfaction, and quality of life perception were considered excellent in both groups. CONCLUSIONS: No long-term clinical benefit of VDD over VVI pacing could be identified in the present study.

Use of multidetector computed tomography in the assessment of dogs with pericardial effusion.

BACKGROUND: Contrast-enhanced multidetector computed tomography (MDCT) allows high spatial and temporal resolution imaging of cardiac, thoracic, and abdominal structures. Accurate determination of the cause of pericardial effusion (PE) is essential to providing appropriate treatment and prognosis. Echocardiography and pericardial fluid analysis may not differentiate between causes of PE and cannot identify extracardiac metastasis. HYPOTHESIS/OBJECTIVES: Describe the thoracic and abdominal MDCT findings and evaluate the utility of MDCT to differentiate between neoplastic and nonneoplastic causes of PE in dogs. ANIMALS: Eleven client-owned dogs with PE diagnosed by echocardiography. METHODS: Prospective observational study. Transthoracic echocardiography (TTE), 3-view thoracic radiography, and contrast-enhanced thoracic and abdominal MDCT images were evaluated for the presence of cardiac masses, pulmonary metastases, and abdominal masses. Histopathology in 5 dogs and survival analysis in all dogs were evaluated. RESULTS: A neoplastic cause was identified in 6/11 dogs and a nonneoplastic cause was identified in 5/11. Cardiac MDCT findings were consistent with TTE findings in all dogs with right atrial (5/5) and heart base masses (1/1). Pulmonary metastases were identified in 1/11 dogs by thoracic radiography and in 2/11 dogs by MDCT. MDCT identified splenic or hepatic lesions consistent with neoplasia in 6/11 and 5/11 dogs, respectively. Focal MDCT pericardial changes at the pericardiocentesis site were noted in 3/11 dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Multidetector computed tomography did not improve the detection of cardiac masses in dogs with PE over echocardiography. The benefit of MDCT was primarily in the detection of pulmonary metastases and extracardiac lesions using a single imaging modality.

Management of incidentally detected heart murmurs in dogs and cats.

A dog or a cat has an incidentally detected heart murmur if the murmuris an unexpected discovery during a veterinary consultation that was not initially focused on the cardiovascular system. This document presents approaches for managing dogs and cats that have incidentally-detected heart murmurs, with an emphasis on murmur characteristics, signalment profiling, and multifactorial decision-making to choose an optimal course for a given patient.

A chemical burn from a garlic poultice applied to the face to treat toothache: a case report.

This case report is of a significant chemical burn to the face resulting from the use of an external garlic poultice for toothache. The patient used internet search engines to seek a toothache remedy and did not identify any reports of this complication. This report aims to inform all dentists of the risks of raw garlic application to the skin and also to ensure that in the future any patient using the internet for a toothache remedy will be made aware of the potential risk and how to avoid it.

Association of dilated cardiomyopathy with the striatin mutation genotype in boxer dogs.

BACKGROUND: Myocardial disease in the Boxer dog is characterized by 1 of 2 clinical presentations, dilated cardiomyopathy (DCM) characterized by ventricular systolic dysfunction, dilatation and tachyarrhythmias, and arrhythmogenic right ventricular cardiomyopathy (ARVC) characterized by ventricular tachyarrhythmias, syncope, and sudden death. Boxer ARVC has been associated with a deletion in the striatin gene in some families. HYPOTHESIS/OBJECTIVES: We hypothesized that both presentations represent a single disease, and the development of DCM in the Boxer is associated with the striatin deletion. ANIMALS: Thirty-three adult Boxer dogs with DCM, 29 adult Boxer dogs with the striatin deletion and ARVC, and 16 Boxers without cardiac disease. METHODS: DNA samples were evaluated for the striatin deletion. Association of the deletion with the DCM phenotype was tested by a Fisher's exact test. T-tests were used to evaluate potential differences between the positive heterozygous and positive homozygous groups with DCM with regard to age, LVIDD, LVIDS, and FS%. RESULTS: Thirty of 33 dogs with DCM were positive for the striatin deletion. The striatin mutation and the homozygous genotype were strongly associated with the DCM phenotype (P < .001 and P = .005). There was no statistical difference between the heterozygous and homozygous groups with regard to age and echocardiographic measurements. CONCLUSIONS AND CLINICAL IMPORTANCE: This study demonstrates an association between DCM in the Boxer dog and the striatin mutation, particularly with the homozygous genotype. The observation that 3/33 dogs developed DCM and lacked the striatin mutation suggests that there is at least 1 other cause of DCM in the Boxer dog.

Validation of a commercially available enzyme immunoassay for measurement of plasma antidiuretic hormone concentration in healthy dogs and assessment of plasma antidiuretic hormone concentration in dogs with congestive heart failure.

OBJECTIVE: To validate the use of a human enzyme immunoassay (EIA) kit for measurement of plasma antidiuretic hormone (ADH) concentration in dogs and evaluate plasma ADH concentrations in dogs with congestive heart failure (CHF) attributable to acquired cardiac disease, compared with findings in healthy dogs. ANIMALS: 6 healthy dogs and 12 dogs with CHF as a result of chronic degenerative valve disease or dilated cardiomyopathy. PROCEDURES: Plasma samples from the 6 healthy dogs were pooled and used to validate the EIA kit for measurement of plasma ADH concentration in dogs by assessing intra-assay precision, dilutional linearity, and spiking recovery. Following validation, plasma ADH concentrations were measured in the 6 healthy dogs and in the 12 dogs with CHF for comparison. RESULTS: The EIA kit measured ADH concentrations in canine plasma samples with acceptable intra-assay precision, dilutional linearity, and spiking recovery. The intra-assay coefficient of variation was 11%. By use of this assay, the median plasma concentration of ADH in dogs with CHF was 6.15 pg/mL (SD, 3.2 pg/mL; range, 4.18 to 15.47 pg/mL), which was significantly higher than the median concentration in healthy dogs (3.67 pg/mL [SD, 0.93 pg/mL; range, 3.49 to 5.45 pg/mL]). CONCLUSIONS AND CLINICAL RELEVANCE: Plasma ADH concentrations in dogs can be measured with the tested EIA kit. Plasma ADH concentrations were higher in dogs with CHF induced by acquired cardiac disease than in healthy dogs. This observation provides a basis for future studies evaluating circulating ADH concentrations in dogs with developing heart failure.

Hypoplastic aberrant left subclavian artery in a dog with a persistent right aortic arch.

Vascular ring anomalies (VRA) are relatively uncommon cardiovascular disorders in canine patients. The most common VRA is a persistent right aortic arch (PRAA) with a left ligamentum arteriosum, however various other vascular anomalies resulting in tracheoesophageal compression have also been reported. We report a case of a dog with a PRAA and left ligamentum arteriosum with a hypoplastic aberrant left subclavian artery resulting in asymmetric cervicobrachial circulation. Selective angiography and ECG-gated multi-detector computed tomography were utilized in the evaluation of these defects. The case presented represents a unique vascular anomaly of the aortic arch not previously described in veterinary medicine.

Anomalous left-to-right shunting communication between the ascending aorta and right pulmonary artery in a dog.

Anomalies of conotruncal septation are rare in dogs and uncommon in humans. Congenital conotruncal defects most commonly reported in veterinary medicine include aorto-pulmonary window and persistent truncus arteriosus. We report a case of an anomalous vessel connecting the ascending aorta to the right pulmonary artery causing left-to-right shunting, left-sided volume overload, and pulmonary overcirculation. Transesophageal echocardiography, cardiac catheterization, and contrast-enhanced computed tomography assisted in the diagnosis and facilitated the surgical correction of the anomalous vessel. The authors hypothesize this defect represents an unusual anomalous vessel connecting the ascending aorta to the right pulmonary artery.