Ultrasonographic study of ovary in agoutis (Dasyprocta prymnolopha) bred in captivity, during the estrous cycle

The use of native wild animals has been an alternative activity for producer income and subsistence in regions that presents many difficulties to have traditional livestock. The agouti is a rodent that has shown efficiency on captivity production, so deeper technics and studies about its reproductive physiology are tools to amplify and optimize its productive scale. The objective of this paper was characterizing ovarian morphological changes in agouti (Dasyprocta primnolopha) species bred in captivity on Patos city, Paraiba, Brazil, by Ultrasonograpy study. The experiment has done in Morphologic Sciences Lab of Veterinary Medicine Academic Unit (UAMV), Federal University of Campina Grande (UFCG). The animals were obtained in partnership with NEPAS (Wild Animals Center of Studies and Preservation), in Federal University of Piaui, Teresina-PI. The methodologic protocols were approved by Environment Ministry, SISBIO No 47944-1, and by the UFCG’s Ethic Committee on Animals Use, CEP No 237 - 2014. Ultrasonography was realized during every experiment phase when ovarian cycle change was detected through vaginal cytology aiming evaluate ovaries morphological changes. The animals were caught using a dip nets, they were mechanically held with leather gloves help and sent to Veterinary Anatomy Lab of Rural Health and Technology Center in Campus – Patos – PB. With the animals mechanically held and previously trichotomized on abdomen’s side region (right and left flanks) until sublumbar muscles high. We used 5 females of Dasyprocta prymnolopha species and a vasectomised male for stimulate females’ cycle. It was followed all phases of females’ estrous cycle through vaginal colpocytology, as reference for ultrasonography evaluations realized by a portable Ultrasound equipment, with coler doppler of MINDRAY® brand, linked to a multifrequency linear transducer to identify morphologic changes of both ovaries to each phase of estrous cycle. We observed that the length of estrous cycle was 28.2±12.6 days, with 3.5±2.4 days for proestrus, 1.75±0.5 days for estrus, 5±0.8 days for metestrus and 18±9.4 days for diestrus. The left ovary is dorsally located, next to upper abdominal cavity, caudally to left kidney, attached to up side by the suspensory ligament of the ovary; the right ovary was more caudoventral to right kidney, suspended in the cavity by the suspensory ligament of the ovary. From ultrasound exam was possible stablish access through right and left flank, generating a constant window delimited for the kidneys right and left as well, cranially from dosrsally suspensory ligament of the ovary and from ovary’s arteries and veins ventrally, forming a triangle of caudal vertex with the ovary located on this vertex. Measurements were made getting the ovaries length and width, as length average of 0.78 ± 0.09cm and as width average of 0.32±0.05cm to left ovaries and a length average of 0.76±0.09cm and a width average of 0.31±0.05cm to right ovaries. No differences were observed in the ovary size at different estrous cycle phase (P<0,05). The follicular phase was well characterized by the appearance of one or two follicles well seen on sonography exam. Neither the corpus luteum nor atreitic follicles was possible to be observed by ultrasound exam. Despite the ultrasonography has shown its efficiency on follicular phase identification, other complementary exams must be realized to other phases distinction.