Journal Article

Electrocardiographic and echocardiographic profiles of white-lipped peccaries ( Tayassu pecari ) under ketamine-dexmedetomidine or ketamine-midazolam anesthesia

Valandro, Marilia Avila, Barbosa, Helena Bulhões, Gorczak, Rochelle, Niella, Raquel Vieira, de Lavor, Mário Sérgio Lima

2026

Overview

White-lipped peccaries ( ) are key frugivores in Neotropical ecosystems and are classified as a vulnerable species, highlighting the need for safe, evidence-based anesthetic protocols for clinical management and conservation actions. To the best of our knowledge, this is the first study to investigate the effects of different dissociative anesthetic protocols on electrocardiographic and echocardiographic parameters in white-lipped peccaries, as well as to establish preliminary cardiovascular reference values for the species. Sixteen clinically healthy adult males, with a mean body weight of 30.7 kg, were evaluated and subjected to anesthesia with ketamine combined with midazolam administered intramuscularly (IM) or ketamine combined with dexmedetomidine administered either IM or intravenously (IV). Electrocardiographic (ECG) monitoring was performed for 30 min to assess mean heart rate (HR), waveform morphology, and the duration of waves and intervals. Echocardiography (ECHO) was used to measure ventricular dimensions, interventricular septal and myocardial wall thicknesses, as well as left atrial and aortic dimensions. The IM dexmedetomidine protocol resulted in a significant reduction in P wave amplitude compared to the midazolam protocol (  = 0.016), whereas IV administration was associated with a lower T wave amplitude compared to IM dexmedetomidine (  = 0.01) and a lower mean HR when compared to the midazolam group (  = 0.03), in addition to the occurrence of supraventricular and ventricular arrhythmias and second-degree atrioventricular block. No morphological cardiac abnormalities were detected on ECHO; however, a significant reduction in interventricular septal thickness during diastole was observed in the IM dexmedetomidine group (  = 0.01), without statistically significant changes in quantitative parameters. These findings provide the first integrated ECG and ECHO reference values for , supporting safer anesthetic decision-making, improved clinical management, and evidence-based conservation strategies.

• Publisher: Frontiers Media SA,Frontiers Media S.A
• Subject: Abnormalities / Agonists / Amplitudes / Anesthesia / Animals / Body weight / cardiology / Conservation / Decision making / Diastole / dissociative anesthesia / Drug dosages / Echocardiography / EKG / Electrocardiography / Frugivores / heart / Heart rate / hemodynamics / Ketamine / Midazolam / Morphology / Original Research / P waves / Parameters / Physical restraints / Statistical analysis / Tayassu / Tayassu pecari / Tayassuidae / Thickness / Threatened species / Ultrasonic imaging / Variance analysis / Ventricle / Veterinary medicine / Waveforms / wild mammal / Wildlife