Abstract

Five sonic thermistors (14x57 mm, weighing 9.1 g) were inserted into the gastrointestinal tract of 3 captive manatees (Trichechus manatus) to monitor core body temperature during metabolic studies. Preliminary attempts at oral passage using an equine balling gun were met with vigorous resistance by the manatees and damage to one thermistor. Subsequent nasal passage of a stomach tube (19 mm OD x 12 mm ID) was accepted without a struggle by the manatee. A thermistor, held in the tip of the tube, was passed through a nostril into the esophagus (total distance 40 cm). The thermistor was gently forced from the tube by passing a probe through the lumen of the tube. Thermistors were swallowed and passed through the gastrointestinal tract in 6 to 20 days. Manatees appeared to have normal respiration while the tube was in place.

Stomach tube passage through a nostril is preferred to the oral route for introducing materials (thermistors, drugs, etc) into the gastrointestinal tract of manatees.

Notes

The manatee has vestigial turbinate bones, therefore there is little chance of hemorrhage on passing of a stomach tube.