Mural Endocarditis Caused by Corynebacterium mustelae in a Dog With a VSD

A Comprehensive Review of Canine and Feline Ventricular Septal Defects-From Pathogenesis to Long-Term Follow-Up

Congenital heart defects (CHDs) in dogs and cats represent a definite minority of cardiac patients. One of the most commonly diagnosed is ventricular septal defects (VSDs). These are associated with abnormal ventricular septation during the prenatal period; however, the mutations of the genes responsible for this phenomenon are not fully understood. VSDs pose a significant diagnostic challenge due to the multitude of locations in the ventricular septum where they are likely to occur. Therefore, there are many phenotypes of the defect causing many problems in terms of a common nomenclature. Among the various classifications, the latest terminology issued by The International Society for Nomenclature of Paediatric and Congenital Heart Disease (ISNPCHD) considers both electrical conduction pathways and adjacent structures to standardize nomenclature. Further, defects located at different sites can alter both prognosis and subsequent management for the patient; thus, taking accurate measurements is crucial. Among these, the Qp:Qs and VSD:Ao ratios, the direction of blood flow through the defect, its location, the diameter and maximum flow velocity, and the pressure difference between the RV and LV are indicated. Emerging technologies such as 3D echocardiography and cardiac magnetic resonance may provide additional diagnostic value. Altogether, along with clinical symptoms, we should determine further management, involving the monitoring of the patient, the implementation of pharmacological treatment, or referral for surgical closure of the VSD. This review summarizes current knowledge on VSD, where the pathogenesis of the condition, diagnosis, and management, including conventional and surgical methods as well as long-term follow-up, are described, providing a complete overview of the issue.

Candida tropicalis infectious endocarditis in a dog with a patent ductus arteriosus

A 6-month-old male intact miniature Australian Shepherd presented for surgical consultation for a previously diagnosed patent ductus arteriosus. Echocardiogram revealed a patent ductus arteriosus and a hyperechoic oscillating lesion within the main pulmonary artery. Blood cultures and eventual post-mortem examination revealed Candida tropicalis endocarditis. This case report highlights a rare case of fungal endocarditis with both echocardiographic and post-mortem findings.

Mural Endocarditis and Embolic Pneumonia Due to Trueperella pyogenes in an Adult Cow with Ventricular Septal Defect

Bacterial endocarditis represents one of the most frequently acquired cardiac diseases in adult cattle. Congenital heart diseases as a ventricular septal defect can facilitate bacterial endocarditis as a consequence of turbulent blood flow through the defect, causing damage to the endocardium. We describe a case of mural endocarditis associated with a ventricular septal defect in an eight-year-old female Holstein Friesian cow. The cow's history revealed that she had presented dysorexia and a sudden decrease of milk production in the last 10 days prior to the examination. On clinical examination, jugular pulses, tachycardia with irregular heart rate and tachypnea with harsh bronchovesicular sounds were evident. Electrocardiographic examination allowed the diagnosis of an atrial fibrillation with high ventricular response rate. Transthoracic echocardiography revealed a large vegetation originating from the endocardium between the tricuspid and pulmonic valves in the right ventricle outflow. On post-mortem examination, a small muscular septal defect under the right coronary cusp of the aortic valve and a mural vegetative endocarditis were found. An abscess in the chondro-costal junction of the third right rib and metastatic pneumonia were also observed. This case report describes a rare consequence of a small ventricular septal defect that had not been previously diagnosed in an adult cow.

Corynebacterium mustelae Endocarditis in a Dog

A 7-year-old male neutered Labrador Retriever dog presented with acute-onset fever, shifting limb lameness and anorexia, with development of acute respiratory distress. At necropsy, there was vegetative endocarditis, which effaced the aortic valve. Gram staining of impression smears from the aortic valve and kidney revealed numerous gram-positive rods with some coryneform bacteria. Similar coryneform bacteria were isolated on aerobic culture of the aortic valve. Identification was attempted by matrix-assisted laser desorption ionization time-of-flight mass spectrometry and 16S sequencing, the latter of which indicated Corynebacterium mustelae. This is the second reported case of endocarditis in a dog involving C. mustelae and the first with a description of post-mortem pathology. This case is an example of the utility of various modalities to identify facultative anaerobic bacterial pathogens that may be difficult to culture and may be more widespread than previously diagnosed.

Infective aortic valve endocarditis in a cat with patent ductus arteriosus and perimembranous ventricular septal defect

A 3-year-old, male neutered, domestic short-haired cat presented for evaluation of respiratory distress. Transthoracic echocardiography revealed a left-to-right shunting ventricular septal defect, a left-to-right shunting patent ductus arteriosus, and a vegetative growth on the aortic valve leaflet consistent with aortic valve endocarditis. Because of poor response to therapy, the owner elected euthanasia, and a necropsy was performed. Gross necropsy examination confirmed the congenital cardiac defects, and aortic valve endocarditis was noted on the echocardiogram. Histopathological examination revealed diffuse interstitial pneumonia and evidence for systemic septic embolism including renal infarcts and brain microabscesses. To the authors' knowledge, this is the first case report of aortic valve endocarditis in a cat in association with congenital cardiac malformations.

Complete Genome Sequence of the Type Strain Corynebacterium mustelae DSM 45274, Isolated from Various Tissues of a Male Ferret with Lethal Sepsis

The complete genome of Corynebacterium mustelae DSM 45274 comprises 3,474,226 bp and 3,188 genes. Prominent niche and virulence factors are SpaBCA- and SpaDEF-type pili with similarity to pilus proteins of Corynebacterium resistens and Corynebacterium urealyticum and an immunomodulatory EndoS-like endoglycosidase probably catalyzing the removal of distinct glycans from IgG antibodies.