Retrospective Evaluation of Intravenous Enoxaparin Administration in Feline Arterial Thromboembolism.

Induction of a hypocoagulable state is imperative in the treatment of feline arterial thromboembolism. Publications in human medicine report the use of enoxaparin intravenously in selected cases. The aim of our retrospective study was to report the regain of perfusion, short-term outcome, and complications of cats treated with a novel intravenous enoxaparin protocol (1 mg/kg bolus injection followed by 3 mg/kg/day continuous infusion) combined with oral clopidogrel administration. The secondary aim was to report the monitoring of enoxaparin with anti-Xa activity. There were 36 cats included. The probability of reaching limb reperfusion was significantly (p = 0.0148) higher with anti-Xa activity within or above the target range compared to results below the target range (19/21, 90% versus 11/20, 55%). The complications observed were acute kidney injury (15/36, 42%), hemorrhage (2/36, 6%), and neurological signs (6/36, 17%). The most common causes of death/euthanasia were cardiac instability, acute kidney injury, neurological abnormalities, and limb necrosis. The hospital discharge rate was 83% (10/12) for single limb and 29% (7/24) for dual limb thrombosis; the difference was significant (p = 0.0039). The median hospitalization time for the survivors was 119.5 (95-480) h. Our study supports the use of intravenous continuous rate infusion of enoxaparin in combination with oral clopidogrel for cats with aortic thromboembolism. We report similar discharge rates and lower hemorrhage rates than previously reported with thrombolytic treatment.

Transvenous embolization of moderate to large patent ductus arteriosus in dogs using the Amplatzer vascular plug II.

BACKGROUND: Catheter-based occlusion of patent ductus arteriosus (PDA) can be performed using different devices. Transvenous embolization using the Amplatzer vascular plug II (AVP-II) has been studied in humans, but it has not been described in dogs. OBJECTIVE: Evaluate the feasibility and success of transvenous embolization of PDA using the AVP-II in dogs. ANIMALS: Nineteen client-owned dogs with left-to-right shunting PDA, with minimal ductal diameter >2.5 mm. METHODS: Prospective observational study using AVP-II with transvenous access for PDA closure in dogs. RESULTS: Angiography showed a conical ductus with a long (n = 17) or short (n = 2) ampulla. The minimal diameter of the duct was 4.34 ± 1.11 mm, and the maximal diameter of the ampulla was 13.18 ± 3.47 mm. Technical success was achieved in 18 of the 19 (94.7%) patients after the first intervention and in all 19 (100%) patients after the second intervention. Postrelease angiography documented complete occlusion of the PDA in 10 of 19 (52.6%) dogs. Mild flow acceleration or stenosis of the left pulmonary artery was found in 6 and 1 of the 17 analyzed cases, respectively, by Doppler examination. The closure rate 24 hours after intervention was 94.7% (18/19). The remaining dog had a moderate residual shunt, and delayed complete closure after 3 months led to a 100% closure rate. CONCLUSION AND CLINICAL IMPORTANCE: The AVP-II is a safe and effective device for transvenous embolization in dogs with moderate to large PDA.

Correlation of Histopathological Changes in the Left Atrium and Left Atrial Appendage with the Degree of Dilation in Cats.

Although atrial dilation is a common finding in feline cardiac disease, detailed investigations of atrial pathology are rare in cats. The aim of the study was to investigate the correlation between pathohistological findings, morphometric data and the degree of dilation of the left atrial appendage (LAA) in 53 cats. Based on the LAA volume, the samples were grouped into normal/control (group 0, ≤1 ml [n = 9]), mildly dilated (group 1, >1 to ≤2 ml [n = 16]), moderately dilated (group 2, >2 to ≤3 ml [n = 14]) and markedly dilated (group 3, >3 ml [n = 14]) groups, independent of the underlying disease. Samples from the LAA and the left atrium (LA) were histologically evaluated using haematoxylin and eosin- and Picrosirius red-stained sections, and morphometrically analysed using an image analysis system. The degree of endo-, myo- and epicardial fibrosis was directly correlated with increased LAA dilation. Due to cardiomyocyte hyperplasia and hypertrophy, the mean thickness of the atrial wall was significantly greater in groups 1 and 2 than in group 0. Conversely, group 3 had a lower mean atrial wall thickness than groups 1 and 2, which was attributed to increased transmural fibrosis and cardiomyocyte atrophy. These findings reflect intensive dynamic remodelling processes during LA and LAA dilation, indicating that reversibility appears to be limited in cases of severe left atrial dilation.

[Echocardiographic measurements in clinically healthy ferrets without sedation]. / Echokardiografische Untersuchung klinisch gesunder Frettchen ohne Sedation.

OBJECTIVE: Cardiac diseases, predominantly acquired diseases such as valvular insufficiency and cardiomyopathies, are a common problem in domestic ferrets. Aim of the present study was to establish body-weight related echocardiographic reference intervals for standard B- and M-mode parameters, especially of the left atrium, in clinically healthy ferrets without sedation. MATERIAL AND METHODS: Eighteen client-owned healthy, non-sedated ferrets underwent echocardiography in right lateral recumbency. Mean values were calculated from the evaluation of 3 cardiac cycles with good wall differentiation within 3 M-mode measurements in the right parasternal long axis view (level of the chordae tendinae, tip of the mitral valve and level of the aortic root and left atrium). Additionally, measurements of the left atrium (LA) and aorta (Ao) were performed in the short axis view at the level of the aorta and the LA/Ao ratio was calculated. RESULTS: The 9 neutered male and 9 neutered female ferrets had a mean age of 2.6 ± 1.3 years and a mean body weight of 1.04 ± 0.31 kg. M-mode measurements of the left ventricle and the aortic root were possible in all animals. Body weight exerted a significant effect on the ventricular dimensions in diastole and systole as well as on the measurements of the left atrium and the aorta. In the B-mode evaluations, measurements of the aorta and the left atrium were frequently only performable on a static image. A significant effect of body weight on the dimensions of both aorta and left atrium were also apparent in the B-mode measurements. Calculated values such as fractional shorting and LA/Ao-ratio proved to be independent of body weight. CONCLUSION AND CLINICAL RELEVANCE: Standard B- and M- parameters may be used in routine examinations in order to evaluate cardiac morphology in the non-sedated ferret. Consideration of the body weight is warranted in this species.

Assessment of a bedside test for N-terminal pro B-type natriuretic peptide (NT-proBNP) to differentiate cardiac from non-cardiac causes of pleural effusion in cats.

BACKGROUND: Cats with pleural effusion represent common emergencies in small animal practice. The aim of this prospective study was to investigate the diagnostic ability of a point-of-care ELISA (POC-ELISA) for the measurement of N-terminal pro B-type natriuretic peptide (NT-proBNP) to differentiate cardiac from non-cardiac disease in cats with pleural effusion. The sample material for use of this rapid test was either plasma or diluted pleural effusion. Twenty cats with moderate to severe pleural effusion were prospectively recruited. The cats were grouped into two groups, with or without congestive heart failure (CHF; N-CHF), after complete work-up. Blood and effusion were collected in EDTA tubes. Plasma and pleural effusion supernatants were transferred into stabilizer tubes and frozen. POC-ELISA for NT-proBNP was performed with plasma and diluted effusion (1:1). Quantitative NT-proBNP measurement was performed in plasma and diluted and undiluted effusions. RESULTS: Six cats were assigned to the CHF group. Of the 14 cats in the N-CHF group, 6 had concurrent cardiac abnormalities that were not responsible for the effusion. For the detection of CHF, the test displayed respective sensitivities and specificities of 100% and 79% in plasma and 100% and 86% in diluted pleural fluid. Receiver operating characteristic (ROC) analysis for quantitative NT-proBNP measurement of plasma and diluted and undiluted pleural effusions displayed areas under the curve of 0.98, sensitivities of 100% and specificities of 86%. The optimum cut-off was calculated at 399 pmol/l in plasma and 229 pmol/l in the diluted effusion and 467 pmol/l in the undiluted effusion. CONCLUSIONS: POC-ELISA for NT-proBNP in both plasma and diluted pleural effusion was suitable to differentiate cardiac from non-cardiac causes of feline pleural effusion. According to our results, use of pleural effusion is feasible, but dilution of the effusion before measurement seems to improve specificity.

[Cyanosis in a calf with a double outlet right ventricle]. / Zyanose bei einem Kalb mit einem Double Outlet Right Ventricle.

A 4-day-old female Holstein Friesian calf was presented for evaluation of cyanosis and dyspnea. On auscultation, severe bronchovesicular sounds and a systolic heart murmur of grade IV/VI above the tricuspid valve were found. On echocardiography, a marked dextroposition of the aorta (> 50% originating from the right ventricle), leading to both great arteries arising from the right ventricle - a so-called double-outlet right ventricle - was detected. Two ventricular septal defects were present, one in the perimembranous, subpulmonary region, the other non-committed in the muscular region. The subpulmonary ventricular septal defect was responsible for the shunting of unoxygenated blood into the aorta. Additionally, an aneurysma-like atrial septal defect (type secundum) and a large patent ductus arteriosus were visualized. The main pulmonary artery was severely enlarged without the presence of a stenotic defect. The findings could be verified by angiography. Additionally, a diffuse hypoplastic ascending aorta was visualized. Necropsy confirmed the echocardiographic and angiographic findings.

Follow-up of troponin I concentration in dogs with atrioventricular block and dual-chamber pacing in a case-matched study.

BACKGROUND: Increased cardiac troponin I (cTnI) concentration has been reported in dogs with atrioventricular (AV) block before and shortly following pacemaker implantation. The role of AV dyssynchrony, age, or concurrent cardiac disease on cTnI concentration remains unknown. OBJECTIVES: To investigate change in cTnI concentration following dual-chamber pacemaker implantation on short- and long-term follow-up and to compare cTnI values to a case-matched control group. ANIMALS: Thirty-eight client-owned dogs with permanent AV block and 38 matched control dogs. METHODS: Retrospective review of medical records. Pacemaker group consisted of dogs with AV block and dual-chamber pacing. Control group matched the study population in age and cardiac disease. cTnI was compared between pacemaker and control group on short- and long-term follow-up. Different lead types and influence of arrhythmia on cTnI were tested. RESULTS: cTnI was high at presentation (median 0.66 ng/ml; range 0.03-18.6) and showed a significant reduction over time after pacemaker implantation (p < 0.0001). Median cTnI values were significantly different between pacemaker and control group on short-term (p = 0.0004; 0.11 ng/ml, range 0.03-1.36 versus 0.06 ng/ml, range 0.03-0.46), but not on long-term follow-up (p = 0.0547; 0.14 ng/ml, range 0.03-0.73 versus 0.07 ng/ml, range 0.03-0.46). Lead type and severity of arrhythmia did not show a significant correlation to cTnI concentration. CONCLUSIONS: On long-term follow-up, cTnI remained mildly elevated in some of the pacemaker dogs but was not significantly different to the matched control group.

Assessment of circulating N-terminal pro B-type natriuretic peptide concentration to differentiate between cardiac from noncardiac causes of pleural effusion in cats.

OBJECTIVE: To determine the diagnostic ability of blood N-terminal pro B-type natriuretic peptide (NT-proBNP) measurement to differentiate between congestive heart failure (CHF) and noncardiogenic causes for moderate to severe pleural effusion in cats. DESIGN: Prospective observational study. SETTING: University teaching hospital. ANIMALS: Twenty-one cats with moderate to severe pleural effusion. INTERVENTIONS: Venous blood sampling for NT-proBNP measurement. MEASUREMENT AND RESULTS: According to the results of echocardiographic examination, cats were classified in a group with CHF (n = 11) or noncongestive heart failure (N-CHF, n = 10). NT-proBNP was measured via a feline-specific test in EDTA plasma with protease inhibitor. NT-proBNP was significantly (P < 0.0001) higher in the CHF group ( median 982 pmol/L, 355-1,286 pmol/L) than in the N-CHF group (median 69 pmol/L, 26 - 160 pmol/L) and discriminated exactly (area under the curve = 1.0, 95% confidence interval 1.0-1.0) between both groups. Optimum cut-off value considering all samples was 258 pmol/L. CONCLUSION: In this small population of cats with pleural effusion, NT-proBNP was able to differentiate between cats with cardiogenic and noncardiogenic causes of effusion. With the currently recommended method of measurement (ie, EDTA plasma with protease inhibitor), a cut-off value of 258 pmol/L discriminates effectively between cats with and without CHF.