Real time B-mode ultrasound in pacas pregnancy (Agouti paca, Linnaeus, 1766)

Abstract

The aim of this study was to establish the pregnancy period of paca by means of ultrasound use. Nine pregnant pacas were periodically scanned with a two-frequency sectorial electronic transducer of 5.0 and 7.5 MHz, in B mode, from ultrasound detection of embryo vesicle or fetus until the parturition. Animals were placed in an iron-bar squeeze cage and remained in standing position during sessions. A dark cloth was used to cover the cage and fruits were offered during ultrasound session to avoid aggressive reactions. The more premature occurred detection of pregnancy, the greater the period of ultrasound examination until the birth of the offspring. All gestation delivered only one newborn weighting 796.5 ± 74.36 grams (mean value ± standard error of the sample) and 33.46 ± 0.60 centimeters (mean value ± standard error of the sample) of length (from rostral edge of nose and distal portion of tail). The length of paca pregnancy ranged from 135 to 139 days.