Page 166 - Small Animal Internal Medicine, 6th Edition

138 PART I Cardiovascular System Disorders

effectiveness of aspirin in reducing vegetative lesion growth animals with an implanted pacemaker or other device, or
and incidence of embolic events is questionable. with a history of endocarditis; it should be considered in
VetBooks.ir repeated cultures 1 to 2 weeks after starting antibiotic therapy immunocompromised animals as well. Recommendations
For animals with positive blood (or urine) cultures,
have included high-dose ampicillin, amoxicillin, or a cepha-
and also 1 to 2 weeks after completion of antibiotic therapy
ratory procedures; clindamycin before dental procedures;
are recommended. Patients with a positive Bartonella anti- losporin 1 hour before and 6 hours after oral or upper respi-
body titer can be retested in 4 weeks after starting antibiotic ampicillin with an aminoglycoside (given IV) one half hour
therapy to verify that titers are decreasing. Persistently ele- before and 8 hours after GI or urogenital procedures; and
vated titers suggest that antibiotic strategy should be changed. ticarcillin or a first-generation cephalosporin (IV) 1 hour
Animals testing positive for Bartonella via serologic and before and 6 hours after a procedure.
BAPGM enrichment blood culture techniques before begin-
ning antibiotic therapy should have these tests repeated at 2
and 6 weeks after therapy has been discontinued to evaluate Suggested Readings
treatment efficacy. Other tests or monitoring may be indi- Degenerative AV Valve Disease
cated depending on the type and severity of concurrent Atkins C, et al. Guidelines for the diagnosis and treatment of canine
disease and secondary complications in the individual chronic valvular heart disease (ACVIM Consensus Statement). J
patient. Recheck echocardiograms during (for example, at 2 Vet Intern Med. 2009;23:1142–1150.
and 8 weeks after starting therapy) and a few weeks following Atkins CE, Haggstrom J. Pharmacologic management of myxoma-
tous mitral valve disease in dogs. J Vet Cardiol. 2012;14:165–184.
the treatment period are indicated to monitor changes in Atkins CE, et al. Results of the veterinary enalapril trial to prove
vegetation size, valve function, chamber dimensions, and LV reduction in onset of heart failure in dogs chronically treated
function. Even if antibiotic therapy is successful in resolving with enalapril alone for compensated, naturally occurring
the infection, progressive cardiac enlargement and myocar- mitral valve insufficiency. J Am Vet Med Assoc. 2007;231:1061–
dial dysfunction are common because of residual valve 1069.
damage and insufficiency. So continued cardiac monitoring Atkinson KJ, et al. Evaluation of pimobendan and N-terminal pro-
is recommended. Radiographs, complete blood count (CBC) brain natriuretic peptide in the treatment of pulmonary hyper-
and serum biochemistry tests, and other tests are repeated tension secondary to degenerative mitral valve disease in dogs. J
as indicated for the individual patient. Vet Intern Med. 2009;23:1190–1196.
Aupperle H, Disatian A. Pathology, protein expression and signal-
Prognosis ling in myxomatous mitral valve degeneration: comparison of
dogs and humans. J Vet Cardiol. 2012;14:59–71.
Long-term prognosis generally is guarded to poor. Some Bernay F, et al. Efficacy of spironolactone on survival in dogs with
dogs die within days to weeks; others that survive the acute naturally occurring mitral regurgitation caused by myxomatous
stages are likely to die later from progressive CHF. Echocar- mitral valve disease. J Vet Intern Med. 2010;24:331–341.
diographic evidence of vegetations (especially of the aortic Birkegard AC, et al. Breeding restrictions decrease the prevalence
valve) and volume overload suggests a poor prognosis. Other of myxomatous mitral valve disease in Cavalier King Charles
negative prognostic indicators include Bartonella or gram- Spaniels over an 8- to 10-year period. J Vet Intern Med. 2016;30:
negative infections, renal or cardiac complications that 63–68.
respond poorly to treatment, septic embolization, and Borgarelli M, et al. Prevalence and prognostic importance of pul-
thrombocytopenia. Glucocorticoid therapy and inadequate monary hypertension in dogs with myxomatous mitral valve
antibiotic therapy can contribute to a poor outcome. Aggres- disease. J Vet Intern Med. 2015;29:569–574.
sive therapy may be successful if valve dysfunction is not Borgarelli M, Buchanan JW. Historical review, epidemiology and
natural history of degenerative mitral valve disease. J Vet Cardiol.
severe and large vegetations are absent. CHF is the most 2012;14:93–101.
common cause of death, although sepsis, systemic emboliza- Borgarelli M, et al. Survival characteristics and prognostic variables
tion, arrhythmias, or renal failure may be the proximate of dogs with preclinical chronic degenerative mitral valve disease
cause. attributable to myxomatous valve disease. J Vet Intern Med.
2012;26:69–75.
Antibiotic Prophylaxis Boswood A, et al. Effect of pimobendan in dogs with preclinical
The use of prophylactic antibiotics is controversial. Experi- myxomatous mitral valve disease and cardiomegaly: the EPIC
ence in people suggests that most cases of infective endocar- study—a randomized clinical trial. J Vet Intern Med. 2016;30:
ditis are not preventable. The risk of endocarditis from a 1765–1779.
specific (e.g., dental) procedure in humans is low compared Chetboul V, et al. Association of plasma N-terminal Pro-B-type
with the cumulative risk associated with normal daily activi- natriuretic peptide concentration with mitral regurgitation
severity and outcome in dogs with asymptomatic degenerative
ties. However, in view of the increased occurrence of endo- mitral valve disease. J Vet Intern Med. 2009;23:984–994.
carditis with certain cardiovascular malformations (especially Chetboul V, Tissier R. Echocardiographic assessment of canine
SAS), antimicrobial prophylaxis usually is recommended for degenerative mitral valve disease. J Vet Cardiol. 2012;14:127–148.
these animals before dental or other “dirty” procedures Diana A, et al. Radiographic features of cardiogenic pulmonary
(those involving the oral cavity or intestinal or urogenital edema in dogs with mitral regurgitation: 61 cases (1998-2007). J
systems). Antimicrobial prophylaxis also is advised for Am Vet Med Assoc. 2009;235:1058–1063.