Introduction

Canine monocytic ehrlichiosis is a highly prevalent disease worldwide, which can lead to death if not treated correctly. It is known that this disease has a high potential to cause myocarditis in sick animals, so a more detailed cardiac evaluation is extremely important.

Objective

The objective of this study was to evaluate the electrical activity and an analysis of the autonomic balance by the indexes of heart rate variability (HRV) of the heart during 24 hours, using the Holter method, of dogs with chronic monocytic ehrlichiosis.

Methods

We used 11 dogs, seven males and four females of varied breed and an average age and weight of 2.4 years and 10.2 kg, respectively, diagnosed with chronic monocytic ehrlichiosis using clinical/hematologic parameters and attesting the bacteria Ehrlichia canis in blood by PCR. In these animals was conducted conventional and ambulatory electrocardiogram (Holter), HRV analysis by the main values of SDNN (ms) and pnn50 (%), blood pressure measurement and analysis of renal and hepatic function.

Results

Three of the 11 animals (27%), presented more than 25 arrhythmic events during the 24 hours, as 203 ventricular premature complexes (VPCs) and 291 supraventricular premature complexes, 12 episodes of supraventricular tachycardia and 7578 VPCs. HRV values showed high prevalence of the sympathetic system, with low values of SDNN (ms) and pnn50 (%) (68.72±44.8±10 and 12, respectively).

Conclusions

Chronic monocytic ehrlichiosis has an important arrhythmogenic factor. Also intensively activates the sympathetic nervous system in the heart of these dogs.