Canine infective endocarditis

Abstract

Canine infective endocarditis is defined as an infection of the endocardium, commonly involving one or more heart valves and leading to proliferative (vegetative) or erosive lesions. Prerequisites for development of infective endocarditis include endocardial damage, formation of a sterile vegetative lesion or coagulum, presence of bacteraemia and microorganism adherence to the coagulum. Predisposing factors include any that may facilitate meeting the prerequisites, including congenital heart disease, extra-oral infections and immunosuppression, amongst others. Large, male, middle-aged and purebred dogs may be overrepresented, in particular Labrador Retrievers, Golden Retrievers, Boxers and German Shepherd Dogs. Typically caused by bacteria, the most common isolates include Streptococcus spp., Staphylococcus spp., Gram-negative rods (particularly Escherichia coli) and Bartonella spp. Blood culture can have low sensitivity, with up to 70% of cultures being negative. Bartonella spp. are increasingly being recognised as a cause of culture-negative aortic infective endocarditis. The preferred method of diagnosis in vivo is echocardiography, with a reported sensitivity of 87.5%. The prognosis is guarded despite appropriate treatment, and some negative prognostic factors have been identified.

Infective endocarditis in dogs in theUK: 77 cases (2009‐2019)

“…Congenital and acquired cardiac diseases were previously shown to predispose dogs to endocarditis (Romero‐Fernandez & Palermo 2019 ). Only two dogs had acquired cardiac disease (MMVD), thus this was not considered to be a major predisposition to IE in this referral population.…”

“… 2004 , Romero‐Fernandez & Palermo 2019 ). Valvular endocardiosis appears to be a predisposing factor for IE in humans; however, this does not appear to be the case in dogs (Kiefer & Bashore 2012 , Romero‐Fernandez & Palermo 2019 ).…”

“…Some suggest small breed dogs are more predisposed due to their predisposition to congenital heart defects, while others suggest medium to large breed dogs are overrepresented (Sisson & Thomas 1984, Miller et al 2004, Romero-Fernandez & Palermo 2019. Valvular endocardiosis appears to be a predisposing factor for IE in humans; however, this does not appear to be the case in dogs (Kiefer & Bashore 2012, Romero-Fernandez & Palermo 2019. IE can be difficult to diagnose ante-mortem due to the nonspecific and variable clinical signs and limited diagnostic capabilities in general practice (Häggström 2010).…”

“…Other Gram-negative bacteria showed a predilection to infect the mitral valve (Sykes et al 2006a). A bacteraemia is required for the development of IE; however, many cases have no clinically detectable source of infection, possibly because many dogs are already receiving antibiotic therapy before the start of a diagnostic work-up (Romero-Fernandez & Palermo 2019). The use of antithrombotics has been shown to increase survival time in IE patients (Reagan et al 2022).…”