International Journal of Morphology
On-line version ISSN 0717-9502
ILLANES, Julio et al. Macroscopic and Microscopic Analysis of the Embryonic and Fetal Growth in the Cat (Felis catus), in Relation to Chorionic Vesicle and Placental Development. Int. J. Morphol. [online]. 2007, vol.25, n.3, pp. 467-481. ISSN 0717-9502. doi: 10.4067/S0717-95022007000300002.
The domestic cat (Felis catus) presents a gestation that lasts 62 ± 5 days. However, gestational age determination in a more precise way is difficult, as there are no analysis that correlate chorionic vesicle size; placental development; embryonic and Fetal development during gestation. In this work 12 gravid uteruses from hybrid cats between 8 and 18 months of age were studied; these were fixed in 10% neutral formaldehyde. For each uterus the chorionic vesicles number was determined. The embryos, fetuses and placenta were removed, measured, weighed and photographed for morphologic analysis. The embryonic and Fetal stages of development were determined according to the external characteristics and structures of the embryos or fetuses, from gastrulation to term. At 13 days of gestation a late gastrula was observed; between days 13 and 18, somitic embryos; between days 18 and 28, prefetal embryos; and fetuses from day 28 until birth. The amnion is closed by day 17; differentiation of the facial region occurs between days 16 and 28, while limb development takes place between days 17 and 28. At 15 days of gestation the heart begins to beat and the endocardial tube is observed. Septation of the heart occurs between days 17 and 20 and the neural tube is closed by day 17. All parameters studied in the different developmental stages in the cat are significantly correlated (p < 0.0001)
Keywords : Cat; Felis catus; Embriology; Embryonic development; Fetal development.