Pregnancy in Hystricomorpha: Gestational age and embryonic-fetal development of agouti (Dasyprocta prymnolopha, Wagler 1831) estimated by ultrasonography

Abstract

Thirty-one pregnant agoutis, between Days 9 and 103 of gestation (Day 1 = day of detection of sperm in the vaginal smear), underwent B-mode ultrasonography; gestational sac diameter (GSD), crown-rump length (CRL), embryonic-fetal diameter (EFD), and placenta diameter (PD) were measured. There were positive correlations (P < 0.05) between GSD and CRL (r = 0.98), GSD and PD (r = 0.88), CRL and PD (r = 0.86), days of gestation (DG) and CRL (r = 0.85), and DG and PD (r = 0.73). The gestational sac was first observed on Day 14. The embryo was first seen on Day 18 in 9/31 of pregnant agoutis and on Day 22 in 20/31 of pregnant agoutis. Heartbeats were detected from the Day 25 and placentas were observed in 100% of the animals from Day 25. Early limb bud and ossification of the fetal skull were identified on Days 27 (15/31) and 45 (24/31), respectively. Fetal orientation (head and body) was evident from Day 40, the stomach, liver and lungs were identified on Day 50, the kidneys were reliably seen only on Day 55, and the aorta and vena cava were seen on Day 70. The fetal bowel and the urinary bladder were the last structures to be observed (Day 85). Ultrasonography was effective for early pregnancy diagnosis in agouti and for obtaining information on embryonic and fetal structures that could be used to predict gestational age and birth, thereby contributing to their reproductive management in captivity.

Monitoramento do ciclo estral de cutias (Dasyprocta leporina Lichtenstein, 1823) através de citologia esfoliativa vaginal e ultrassonografia

“…Nos últimos anos, diversos conhecimentos têm sido gerados no tocante à biologia reprodutiva das cutias, como a caracterização morfológica dos ovários (Almeida et al 2003), tubas uterinas (Fortes et al 2005), placentação (Rodrigues et al 2003) e criopreservação de folículos pré-antrais (Wanderley et al 2012) em D. leporina, bem como o diagnóstico de gestação por ultrassonografia em D. prymnolopha (Sousa et al 2012). Das 11 diferentes espécies de cutias catalogadas, genericamente conhecidas como D. aguti, apenas sete habitam o território brasileiro (Woods & Kilpatrick 2005), no entanto, diferentes aspectos reprodutivos entre as diferentes espécies permanecem não elucidados.…”

“…Em roedores silvestres, estudos relacionados à aplicação da técnica de ultrassonografia à reprodução são escassos. Existem apenas relatos da sua utilização para estimar a previsão do parto em pacas (Agouti paca) (Oliveira et al2003) e para o acompanhamento gestacional em cutias D. prymnolopha (Sousa et al 2012).…”

Use of Real-Time Ultrasonography as an Alternative Method for Early Detection, Confirmation and Evaluation of Rat Pregnancy

“…Because of advances in ultrasound imaging technology, commercially available ultrasound systems now have the spatial and temporal resolution to obtain accurate images of rat and mouse hearts, kidneys and other organs (Coatney 2001;Golden et al 2012;Kobayashi et al 2001;Srinivasan et al 1998;Stypmann 2007). For this reason, ultrasound is a practical method for the diagnosis of pregnancy in agouti mice (Sousa et al 2012), staging of gestation and monitoring of intrauterine growth in rats (Brown et al 2006;Mu et al 2008;Nguyen et al 2012;Pallares and Gonzalez-Bulnes 2009;Ypsilantis et al 2009).…”

Serum biochemistry in hystricomorpha: agouti (Dasyprocta prymnolopha) during pregnancy

“…This animal is being a rich source of protein and hunting target in the region, but is not on the list of endangered animals (BRASIL, 2016). In this way, its production in captivity is expanding, since several research groups are developing studies on its morphology, ultrasonographic and echocardiographic evaluation, as well as a biological model for alternative treatments of chronic diseases (CABRAL et al, 2012 ;CARVALHO et al, 2015 ;DINIZ et al, 2013 ;FORTES et al, 2013;SILVA et al 2014 ;SOUSA et al, 2013). Blood is responsible for transporting and micronutrient elements related to metabolism and thus its analysis reflects the physiological situation of individual.…”