Objective—To evaluate the anatomic distribution and electrophysiologic properties of accessory pathways (APs) in dogs.
Animals—10 dogs with tachyarrhythmias associated with an AP.
Procedures—Each dog underwent electrophysiologic testing to determine the inducibility of documented and undocumented arrhythmias and to identify location, conduction properties, and antegrade and retrograde effective refractory periods of the APs. Radiofrequency catheter ablation was then performed.
Results—15 APs were identified; 7 dogs each had a single AP, and 3 had multiple APs. Fourteen of the 15 APs were right-sided (6 right free wall, 4 posteroseptal, 3 midseptal, and 1 anteroseptal), and 1 was left-sided (left free wall). All APs conducted in an all-or-none fashion. Unidirectional retrograde conduction was observed in 11 APs, and bidirectional conduction was observed in 4. All documented tachyarrhythmias could be induced during electrophysiologic testing; atrial fibrillation was also inducible in 2 dogs. Mean ± SD cycle duration of orthodromic atrioventricular reciprocating tachycardia was 215.80 ± 44.87 milliseconds. Mean shortest R-R interval during atrial fibrillation was 247.33 ± 83.17 milliseconds.
Conclusions and Clinical Relevance—Results suggested that in dogs, most APs are right-sided, had unidirectional retrograde conduction, and are associated with various arrhythmias, including orthodromic atrioventricular reciprocating tachycardia and atrial fibrillation without evidence of pre-excitation.
Objective—To histologically identify glomerular
lesions in dogs infected with Leishmania organisms.
Animals—41 dogs (17 sexually intact males and 14
sexually intact and 10 ovariohysterectomized females)
that had positive results when tested for leishmaniosis
as determined by use of serologic evaluation (indirect
fluorescent antibody test, titers of 1:80 to 1:640)
and direct microscopic identification of the protozoal
Procedure—Urine samples were collected by use of
cystocentesis and examined by qualitative SDSagarose
gel electrophoresis (AGE). All dogs had nonselective
(glomerular) or mixed (glomerular and tubular)
proteinemia. Specimens were obtained from each
dog during ultrasound-assisted renal biopsy and used
for histologic examination. Each specimen was
stained with H&E, periodic acid–Schiff, Goldner's
trichrome, methenamine silver, and Congo Red
stains. Specimens were adequate for evaluation
when they contained at least 5 glomeruli/section,
except for specimens stained with Congo Red in
which 1 glomerulus/section was adequate.
Results—Examination of renal biopsy specimens
revealed various glomerular lesions in all dogs and
interstitial or tubular (or both) lesions in 23 of 41
Conclusions and Clinical Relevance—Glomerular
lesions that develop in dogs during infection with
Leishmania organisms can be classified histologically
as mesangial glomerulonephritis, membranous
glomerulonephritis, membranoproliferative glomerulonephritis,
and focal segmental glomerulonephritis.
Tubulointerstitial histopathologic conditions were not
observed as the primary lesion, despite being evident
in 23 of 41 (55%) dogs. Use of SDS-AGE for qualitative
evaluation of proteinuria and successive collection
of specimens during renal biopsies following
diagnosis of nonselective glomerular proteinuria provides
the possibility for early identification of renal
lesions. (Am J Vet Res 2003;64:558–561)
Objective—To evaluate reproducibility of ejection fraction (EF), myocardial perfusion (MP), and pulmonary transit time (PTT) measured in a group of dogs by use of contrast echocardiography and to examine safety of this method by evaluating cardiac troponin I concentrations.
Animals—6 healthy dogs.
Procedures—2 bolus injections and a constant rate infusion of contrast agent were administered IV. Echocardiographic EF was determined by use of the area-length method and was calculated without and with contrast agent. The PTT and normalized PTT (PTT/mean R-R interval) were measured for each bolus. Constant rate infusion was used for global MP evaluation, and regional MP was calculated by use of a real-time method in 4 regions of interest of the left ventricle. Cardiac troponin I concentration was analyzed before and after contrast agent administration. Intraoberserver and interobserver variability was calculated.
Results—EF was easier to determine with the ultrasonographic contrast agent. For the first and second bolus, mean ± SD PTT was 1.8 ± 0.2 seconds and 2.1 ± 0.3 seconds and normalized PTT was 3.4 ± 0.3 seconds and 3.5 ± 0.3 seconds, respectively. A coefficient of variation < 15% was obtained for global MP but not for the regional MPs. No differences were detected between precontrast and postcontrast cardiac troponin I concentrations.
Conclusions and Clinical Relevance—Contrast echocardiography appeared to be a repeat-able and safe technique for use in the evaluation of global MP and PTT in healthy dogs, and it improved delineation of the endocardial border in dogs.