Aortic valvular endocarditis associated with Pasteurella haemolytica in a tiger (Panthera tigris)

Infective vegetative endocarditis of the mitral, aortic, and pulmonary valves due to Enterococcus hirae in a cat with a ventricular septal defect

A 2.5-year-old female intact British Shorthair was presented for progressive complaints of abdominal distention, increased respiratory effort, lethargy and hyporexia. Based on the clinical presentation and a loud heart murmur, a cardiac cause was suspected. An echocardiogram was performed and the presumptive diagnosis of infective endocarditis of the aortic, mitral and pulmonic valves was made. Antemortem blood culture and postmortem valve biopsy confirmed bacterial endocarditis with Enterococcus hirae as etiological agent. To the authors' best knowledge, this case report is the first to describe an infective endocarditis with vegetative lesions on three cardiac valves associated with a ventricular septal defect in a cat, and Enterococcus hirae as causative agent for endocarditis in small animals.

ECHOCARDIOGRAPHIC PARAMETERS IN EIGHT ADULT TIGERS ( PANTHERA TIGRIS) DURING TWO PHASES OF AN ANESTHETIC PROTOCOL

Eight adult tigers ( Panthera tigris) underwent a complete echocardiographic examination following sedation with medetomidine, midazolam, and induction of general anesthesia using ketamine and isoflurane (phase 1). Atipamezole was used to antagonize medetomidine (phase 2) and a second echocardiographic examination was performed. Physiologic tricuspid and pulmonic regurgitations were common findings in the sample population and one tiger was excluded from final analyses due to the finding of a ventricular septal defect. Measurements and mean arterial pressure were assessed for statistically significant differences between the two examination phases as well as gender and weight. There was a statistically significant difference between interventricular septum thickness at end systole, ejection fraction, and mean arterial pressure between anesthetic phases while fractional shortening and left ventricular internal dimension at end-systole approached, but did not reach, statistical significance between phases. Weight was found to be a statistically significant predictor of stroke volume and left ventricular internal dimension at end-diastole. The echocardiographic measurements obtained during this study can be used as guidelines for future examinations in adult tigers. The effects of medetomidine on these measurements and systolic function should be taken into account when performing echocardiograms and monitoring anesthetic events.

Bartonella spp. as a Possible Cause or Cofactor of Feline Endomyocarditis-Left Ventricular Endocardial Fibrosis Complex

Endomyocarditis is a commonly detected post-mortem finding in domestic cats presenting for sudden onset cardiovascular death, yet the aetiology remains unresolved. Cats are documented reservoir hosts for Bartonella henselae, the infectious cause of cat scratch disease in man. Various Bartonella spp. have been associated with culture-negative endocarditis, myocarditis and sudden death in man and animals. We hypothesized that Bartonella spp. DNA could be amplified more often from the hearts of cats with feline endomyocarditis-left ventricular endocardial fibrosis (FEMC-LVEF) complex compared with cats with hypertrophic cardiomyopathy (HCM) or cats with grossly and microscopically unremarkable hearts (designated non-cardiac disease controls). Formalin-fixed and paraffin wax-embedded, cardiac tissues from 60 domestic and purebred cats aged 3 months to 18 years were examined, and histological features were recorded. Cardiac tissue sections were tested for Bartonella DNA using multiple 16-23S intergenic transcribed spacer region polymerase chain reaction (PCR) primer sets, including two Bartonella genera, a Bartonella koehlerae species-specific and a Bartonella vinsonii subsp. berkhoffii-specific assay, followed by DNA sequence confirmation of the species or genotype. Special precautions were taken to avoid DNA cross-contamination between tissues. Bartonella spp. DNA was amplified by PCR and sequenced from 18 of 36 cats (50%) with FEMC-LVEF and 1/12 (8.3%) cats with HCM. Bartonella spp. DNA was not amplified from any non-cardiac disease control hearts. Based on PCR/DNA sequencing, one Bartonella spp. was amplified from 10 cats, while the remaining eight were coinfected with more than one Bartonella spp. To our knowledge, this study represents the first documentation of B. vinsonii subsp. berkhoffii genotype I infection in cats (n = 11). Fluorescence in-situ hybridization testing facilitated visualization of Bartonella bacteria within the myocardium of four of seven PCR-positive FEMC-LVEF hearts. Collectively, these findings support the hypothesis that Bartonella spp. may play a primary role or act as a cofactor in the pathogenesis of FEMC-LVEF. Studies involving cats from other geographical regions and definitive demonstration of Bartonella spp. within regions of inflammation are needed to confirm an association between Bartonella spp. and FEMC-LVEF induced morbidity and mortality in cats.

Current diagnosis and treatment of infective endocarditis

The incidence of infective endocarditis continues to rise with a yearly incidence of around 15,000 to 20,000 new cases in the USA. As a result, rapid diagnosis, effective treatment and prompt recognition of complications are essential to desirable clinical outcomes. Recent guidelines such as the Duke criteria have incorporated echocardiography for diagnosis of infective endocarditis, making this diagnostic test mandatory for patients with suspected infective endocarditis. The diversity of pathogens that can cause infective endocarditis, some of which cannot be cultured easily, makes diagnosis even more difficult. Coagulase-negative staphylococci and viridans streptococci groups continue to be the major causative microorganisms of infective endocarditis. In the case of culture-negative endocarditis or infective endocarditis caused by fastidious microorganisms, the polymerase chain reaction and probe-based diagnostic methods are available to clinical reference laboratories.

Infectious Endocarditis and Chylothorax in a Cat

A 6 yr old domestic longhair cat was evaluated for progressive weight loss, weakness, and dyspnea. Results of a physical examination and electrocardiogram were suggestive of cardiac disease. Thoracic radiographs revealed pleural effusion, which thoracocentesis revealed was consistent with chyle. An echocardiogram was performed, and aortic valve endocarditis with secondary aortic insufficiency was presumptively diagnosed. The cat was treated with broad-spectrum oral antibiotics and palliative cardiac medications. Two days after discharge, the cat's dyspnea returned, and it died suddenly. Histopathology and culture confirmed Pseudomonas bacterial endocarditis of the aortic valve. Bacterial endocarditis in the cat has rarely been reported in the literature. This case described heart failure and chylothorax resulting from bacterial endocarditis.