Successful treatment ofBartonella henselaeendocarditis in a cat

Abstract

This report describes the clinical presentation, diagnosis and treatment of a cat with vegetative valvular endocarditis temporally associated with natural infection with Bartonella henselae. Lethargy, abnormal gait and weakness were the main clinical signs that resulted in referral for diagnostic evaluation. Using a novel and sensitive culture approach, B henselae was isolated from the blood. Following antibiotic therapy there was total resolution of clinical signs, the heart murmur, the valvular lesion by echocardiography, and no Bartonella species was isolated or amplified from a post-treatment blood culture. In conjunction with previous case reports, infective endocarditis can be associated with natural B henselae infection in cats; however, early diagnosis and treatment may result in a better prognosis than previously reported.

Suspected Bartonella-associated myocarditis and supraventricular tachycardia in a cat

“…Serologic testing after therapy may be useful when attempting to document therapeutic elimination of Bartonella species infections, as clinical improvement is usually accompanied by a decrease in antibody titer. 8,12 The four-fold reduction in antibody titer in this case is the same magnitude as that seen in a cat with Bartonella-associated endocarditis of the mitral valve which responded successfully to therapy. 8 SVT refers to a paroxysmal tachyarrhythmia which requires atrial or atrioventricular nodal tissue or both for their initiation and maintenance.…”

“…8,12 The four-fold reduction in antibody titer in this case is the same magnitude as that seen in a cat with Bartonella-associated endocarditis of the mitral valve which responded successfully to therapy. 8 SVT refers to a paroxysmal tachyarrhythmia which requires atrial or atrioventricular nodal tissue or both for their initiation and maintenance. ECG characteristics usually include a narrow QRS complex with a regular ReR interval and the focus of origin may be located in the sinus node, atrial tissue, or the AV junction.…”

“…5,6 There have also been case reports of spontaneous Bartonella-associated endocarditis in cats. 7,8 Options for the diagnosis of Bartonella include measurement of Bartonella antibodies, amplification of Bartonella deoxyribonucleic acid (DNA) by polymerase chain reaction (PCR), or culture of Bartonella organisms from blood or tissues. 2,3 However, definitive diagnosis of Bartonella is difficult as the diagnostic value of each test remains unclear.…”

“…2 stringent quality control to avoid both falsepositive and false-negative results, can be expensive to perform, and are currently not standardized. 2,3,8 True positive PCR assay results document presence of Bartonella DNA but do not prove that the organism was alive or that the cat was clinically ill from the infection. 2,3 False-negative PCR assay results can occur because of intermittent bacteremia, previous use of antibiotics, lack of microbial DNA in the sample tested, or interfering substances in biologic specimens.…”

“…3 Recently, antibiotic resistance genes in B. henselae have been identified, which suggests that alternative treatment options may be required in some cats. 8 Paired serology in this case was used to support the diagnosis and resolution of the suspected Bartonella infection after azithromycin therapy. Serologic testing after therapy may be useful when attempting to document therapeutic elimination of Bartonella species infections, as clinical improvement is usually accompanied by a decrease in antibody titer.…”