Evaluation of Echocardiographic, Conventional Electrocardiographic, and Holter Variables in Jaguars (Panthera Onca) Anesthetized with Medetomidine and Ketamine: Implications for Management and Conservation

Abstract

Jaguars play a crucial role in population control across multiple biomes. They are endangered and protected by in situ and ex situ conservation mechanisms to ensure their conservation. Cardiovascular diseases in wild mammals, including jaguars, often have unclear etiopathogenies, underscoring the need for research into novel hemodynamic parameters. This study evaluates the cardiovascular health of fifteen clinically healthy jaguars using conventional and Holter electrocardiography, non-invasive systemic blood pressure measurement, and echocardiography. Chemical restraint was achieved with medetomidine (0.08–0.1 mg/kg) and ketamine (5 mg/kg), with anesthesia reversed using atipamezole (0.25 mg/kg). The average heart rate was 72 ± 18 bpm, with sinus rhythm in ten animals and sinus arrhythmia in five. Six animals exhibited first and second-degree atrioventricular blocks, one had supraventricular complexes, and another had premature ventricular complexes. Non-invasive systolic blood pressure remained stable at 163 ± 29 mmHg during anesthesia. Echocardiographic examination revealed mitral, tricuspid, pulmonary, and aortic valve insufficiencies via color Doppler. The transmitral flow showed a normal E/A ratio and E` < A`, suggesting a pseudonormal ventricular filling pattern. No significant anesthetic complications were observed, affirming the protocol’s safety. This study provides valuable data, validating the anesthetic protocol and establishing reference cardiovascular values for jaguars, thus paving the way for future research in other veterinary species.