Consensus Statements of the American College of Veterinary Internal Medicine (ACVIM) provide veterinarians with guidelines regarding the pathophysiology, diagnosis, or treatment of animal diseases. The foundation of the Consensus Statement is evidence-based medicine, but if such evidence is conflicting or lacking, the panel provides interpretive recommendations on the basis of their collective expertise. The Consensus Statement is intended to be a guide for veterinarians, but it is not a statement of standard of care or a substitute for clinical judgment. Topics of statements and panel members to draft the statements are selected by the Board of Regents with input from the general membership. A draft prepared and input from Diplomates is solicited at the ACVIM Forum and via the ACVIM Web site and incorporated in a final version. This Consensus Statement was approved by the Board of Regents of the ACVIM before publication.

Consensus Statements of the American College of Veterinary Internal Medicine (ACVIM) provide veterinarians with guidelines regarding the pathophysiology, diagnosis, or treatment of animal diseases. The foundation of the Consensus Statement is evidence‐based medicine, but if such evidence is conflicting or lacking, the panel provides interpretive recommendations on the basis of their collective expertise. The Consensus Statement is intended to be a guide for veterinarians, but it is not a statement of standard of care or a substitute for clinical judgment. Topics of statements and panel members to draft the statements are selected by the Board of Regents with input from the general membership. A draft prepared and input from Diplomates is solicited at the ACVIM Forum and via the ACVIM Web site and incorporated in a final version. This Consensus Statement was approved by the Board of Regents of the ACVIM before publication.

Cardiac arrhythmias, endocarditis, or myocarditis was identified in 12 dogs, of which 11 were seroreactive to Bartonella vinsonii subspecies berkhoffii antigens. Historical abnormalities were highly variable but frequently included substantial weight loss, syncope, collapse, or sudden death. Fever was an infrequently detected abnormality. Cardiac disease was diagnosed following an illness of short duration in most dogs, but a protracted illness of at least 6 months' duration was reported for four dogs. Valvular endocarditis was diagnosed echocardiographically or histologically in eight dogs, two of which also had moderate to severe multifocal myocarditis. Four dogs lacking definitive evidence of endocarditis were included because of seroreactivity to B. vinsonii antigens and uncharacterized heart murmurs and/or arrhythmias. Alpha proteobacteria were not isolated from the blood by either conventional or lysis centrifugation blood culture techniques. Using PCR amplification and DNA sequencing of a portion of the 16S rRNA gene, B. vinsonii was identified in the blood or heart valves of three dogs. DNA sequence alignment of PCR amplicons derived from blood or tissue samples from seven dogs clustered among members of the alpha subdivision of the Proteobacteria and suggested the possibility of involvement of one or more alpha proteobacteria; however, because of the limited quantity of sequence, the genus could not be identified. Serologic or molecular evidence of coinfection with tick-transmitted pathogens, including Ehrlichia canis,Babesia canis, Babesia gibsonii, or spotted fever group rickettsiae, was obtained for seven dogs. We conclude thatB. vinsonii subsp. berkhoffii and closely related species of alpha proteobacteria are an important, previously unrecognized cause of arrhythmias, endocarditis, myocarditis, syncope, and sudden death in dogs.

Left ventricular hypertrophy signals a poor prognosis in hypertensive humans. Cardiac disease is common in cats with systemic hypertension. The aims of this study were to characterize the echocardiographic findings of cats with systemic hypertension and to determine if reducing the degree of hypertension is associated with resolution of cardiac hypertrophy. Echocardiographic examinations were performed on 19 cats with naturally occurring systemic hypertension. Fourteen of these cats were subsequently studied after a minimum of 3 months of treatment with the antihypertensive agent amlodipine. Hypertensive cats had a significantly thicker interventricular septum in both systole and diastole, thicker left ventricular free wall in both systole and diastole, and larger left atrium compared to the published normal values and 74% (14/19) of the cats met criteria for left ventricular hypertrophy (diastolic septal or free-wall thickness Ͼ 0.60 cm). Systolic blood pressure was lower after treatment (217 Ϯ 25 mm Hg, range: 180-275 mm Hg; and 142 Ϯ 27 mm Hg, range: 90-200 mm Hg). No difference was found in any of the echocardiographic measurements between the untreated and treated cats, although more cats had ventricular hypertrophy before treatment (11/14) than after initiating amlodipine (6/14; P ϭ .006). Ventricular hypertrophy is common in hypertensive cats and may resolve after the initiation of amlodipine.Key words: Calcium channel blocker; Hypertensive heart disease; Ventricular hypertrophy. Heart disease associated with hypertension, characterized primarily by ventricular hypertrophy, is caused in part by the response of the heart to the greater afterload imposed on it by abnormally high arterial pressure.1 Ventricular hypertrophy may lead to myocardial ischemia, impaired diastolic filling, and decreased coronary artery reserve.1 In hypertensive humans, left ventricular (LV) hypertrophy (LVH) is a sign of a poor prognosis and is an independent risk factor for sudden death.1,2 Because of this, reversal of LVH is an important subject of investigation in hypertension research; however, whether reduction of LVH confers protection beyond that created by reducing blood pressure alone is uncertain.3 Apparently, other nonhemodynamic mechanisms also contribute to LVH in hypertensive humans. 3LVH is thought to exist in up to 20% of mildly hypertensive humans and this percentage increases with the severity of hypertension.4,5 Almost 90% of humans that are hospitalized because of hypertension have LVH.6 The primary cardiac response to hypertension is concentric and symmetrical ventricular hypertrophy; however, septal (asymmetric) hypertrophy is also found in hypertensive humans and this is a common variant of hypertrophy in borderline hypertensive adults and hypertensive children. 7-10Cardiac abnormalities are frequently recognized in cats with systemic hypertension. Gainesville, FL 32610; e-mail: snyderp@mail.vetmed.ufl.edu. Submitted March 23, 2000; Revised July 19, 2000; Accepted September 5, 2000 In the reports mentioned ...

Amlodipine besylate, a calcium channel blocker, was used to treat (mean +/- standard deviation [SD], 127 +/- 68 days) 12 cats with systemic hypertension. Amlodipine was administered orally at a dosage of 0.625 mg per cat (range, 0.08 to 0.23 mg/kg body weight; mean dose +/- SD, 0.17 +/- 0.04 mg/kg body weight) once daily as a single agent. Average indirect systolic blood pressure measurements in the 12 cases decreased significantly from 198 to 155 mmHg during amlodipine treatment. Significant changes in body weight and serum creatinine and potassium concentrations were not detected. Amlodipine appears to be a safe and effective oral treatment for systemic hypertension in cats when used chronically once daily as a single agent.