endocarditis Flashcards
What is endocarditis?
- infection and subsequent inflammation and necrosis of endocardium
- infection often spreads to adjacent myocardium
What is the most common cause of endocarditis in most animals?
usually bacterial
What are the most common bacteria in endocarditis in dogs?
- staph
- e. coli
- strep
What is the pathogenesis of endocarditis?
- formation of vegetation resulting in a large, proliferative mass
- pre-existing endocardial damage often necessary
- direct endocardial damage from vegetations
Which statement on endocarditis in the dog is correct?
A. Bacteria directly invade valvular tissue
B. Platelets bind following bacterial colonization
C. Endothelial injury is the initial step leading to endocarditis
D. Bacteremia results in endothelial injury
E. All statements are correct
C. Endothelial injury is the initial step leading to endocarditis
Which valves are most affected in small animals with endocarditis?
mitral > aortic
Which valves are most affected in equine endocarditis?
aortic > mitral
Which valve is most affected in cattle with endocarditis?
tricuspid
What can cause the vegetations that are seen in endocarditis?
- septic emboli
- continuous formation of circulating immune complexes secondary to immune-mediated disease
What predisposing events can cause endocarditis?
- surgery
- septic focus (ex: abscess)
- ruminitis
- thrombophlebitis
- immunosuppressive therapy
What predisposing CV disease can cause endocarditis in dogs?
subaortic stenosis
Which animal is predisposed to endocarditis?
A. Heifer out on grass pasture
B. Poodle with severe mitral regurgitation
C. Cat with HCM
D. Horse with an infected incision site
E. Bichon frise with teeth falling out
D. Horse with infected incision site
What are the clinical signs of endocarditis?
- fever of unknown origin
- anorexia
- lethargy
- lameness
- CHF
- collapse/syncope
- signs of organ infarction
- signs related to immune-complex diseases
(i.e. diverse and vague)
What are some common PE findings of endocarditis?
- murmur
- bounding pulses
- arrhythmias
- injected MM
- lameness
Which abnormality is consistent with endocarditis? A. Thrombocytopenia B. Hypoglobulinemia C. Regenerative anemia D. Eosinophilia
A. Thrombocytopenia
Which statement is correct?
A. The vegetation of endocarditis appears very different from DVD
B. The vegetation tends to grow on the higher pressure side of the valve
C. The vegetation may result in valvular stenosis
D. Valvular insufficiency is an infrequent finding with endocarditis
C. The vegetation may result in valvular stenosis
What test is critical for confirming endocarditis?
blood culture
need 3-4 samples, at least one hour apart, from two different sites
What are the major criteria for diagnosing endocarditis?
- positive blood cultures (2) from typical bug
- positive blood cultures (3) from atypical bug
- evidence of endocardial involvement
What is involved in a definitive diagnosis of endocarditis?
- 2 major bugs
- 1 major and 3 minor
- or 5 minor
What is difficult to culture from blood in endocarditis?
bartonella, a fastidious intracellular bacterium from ticks and fleas
What should antimicrobial therapy consist of for endocarditis?
- bactericidal
- higher serum concentration of drug
- prolonged therapeutic course
How do you treat bartonella sp. in endocarditis?
doxycycline or azithromycin
What is the prognosis for endocarditis?
guarded to grave because valvular damage is permanent, there may be systemic disease, and re-infection can occur
When are prophylactic antibiotics recommended for preventing endocarditis?
- subaortic stenosis
- intracardiac implants
- catheterization procedure
(not recommended for DVD)
