Electrocardiographic parameters of chemically immobilized giant anteaters (Myrmecophaga tridactyla)

The giant anteater (Myrmecophaga tridactyla) is a vulnerable species that is threatened mostly due to anthropogenic pressure. The anteater is a highly specialized insectivore, challenging the species' ex situ maintenance and conservation efforts. Several dietary-associated health issues have been reported in captive anteaters, including heart conditions such as dilated cardiomyopathy. On the other hand, cardiopathy is mainly diagnosed only on necropsy, and lack of clinical reference is one of the constraints. This work describes electrocardiographic parameters in twelve zoo-kept giant anteaters (Myrmecophaga tridactyla). The giant anteaters were evaluated after chemical immobilization. Surface electrocardiography using a digital electrocardiograph was performed to acquire data on the six frontal plane leads. Four animals were placed in both left and right recumbencies to assess changes in waveforms. Nine anteaters were considered healthy and included in the statistics. The mean heart rate and electrical axis were 37.8 bpm ± 3.45 and 75.6º ± 11.43, respectively. ECG parameters results were P wave duration (ms) 89.7 ± 9.2, P wave amplitude (mV) 0.14 ± 0.05, PR segment duration (ms) 148.6 ± 23, R wave amplitude (mV) 1.55 ± 0.56, QRS complex duration (ms) 88.6 ± 12.0, QT interval duration (ms) 529.6 ± 71.2, and T wave amplitude (mV) 0.76 ± 0.21. There was no difference between left or right recumbency. Heart parameters of giant anteaters are similar to other mammals and seem to be influenced both by size and metabolic rate when comparing with other species. This is the first description of ECG parameters in giant anteaters.