pericarditis

• The majority of cases are idiopathic but the possible causative agents include…

  • Viruses
  • Equine viral arteritis, equine influenza
  • (Secondary to) Bacteria
  • Strep. pneumoniae, E.coli and Actinobacillus (sensitive to penicillin)
• Penicillin is the drug of choice initially (even if a bacterial cause is not identified as not treating a bacterial infection can be detrimental) but these cases tend to develop fibrinous effusions which can cause further complications.
• Clinical signs vary but include..

  • Venous distension (Secondary to right sided CHF)
  • Ventral oedema (Secondary to right sided CHF)
  • Muffled heart sounds (due to the presence of fluid around the heart)
  • Pericardial friction rubs (triphasic sounds in time with heart)
  • Pleural effusion
• Diagnosis can be made via…

  • Echocardiography
  • Fluid and fibrin in pericardial sac
  • Compression of cardiac chambers
  • Electrocardiography
  • Small complexes are often seen
  • The main differential is obesity when small complexes are seen
  • Cytology of pericardial fluid (+/- culture) collected via pericardiocentesis
• Treatment involves pericardial drainage and lavage if the right atrium is collapsing (i.e. cardiac tamponade is present due to the pressure from the fluid preventing adequate filling of the heart reducing cardiac output). Some cases require the placement of an indwelling drain and twice daily lavage with antibiotic containing fluids (this greatly improves prognosis). In general, prognosis is good provided treatment is early and aggressive with horses returning to full performance.
• Constrictive disease may occur in chronic cases and this is the potential consequence of the fibrin and fibrous tissue development. This often means that treatment was not provided early enough