Comparative Development of Embryonic Age by Organogenesis in Domestic Dogs and Cats

Abstract

The precise determination of the embryonic chronology is very important in reproductive biotechnologies, especially in estimating embryonic age. Thus, there is a need for greater knowledge and standardization for determining the chronology of embryonic development and functional morphology. We describe aspects of embryonic development in two domestic carnivores to add knowledge about organ peculiarities and for application in veterinary practice, in prenatal development and in the biotechnology fields. We found that the development of differential characteristics of embryonic organs occurs in the first trimester of pregnancy for both species. Thus, using the combination of the crown-rump length, macroscopic analysis and optical microscopy, it is possible to predict gestational age more precisely in animals that lack a defined breed and establish an embryonic pattern.

Buffalo (Bubalus bubali) Late Embryo and Foetus Development: A Morphological Analysis

“…Embryos with 1.2-1.5 cm (AE26/30 days) had pigmented optic placode as observed in equine (1.5 cm) and bovine (1.4 cm) (Assis-Neto et al 2009;Franciolli et al 2011); cranial neuropore opened showing the fourth ventricle and nasal cavity, midbrain, cervical curvature and tail; the pharyngeal arches were distinct and limbs were developed; Pieri et al (2015) showed in dog and cats (1.7 cm) similar results in limbs, and Roballo et al (2013) described the pharyngeal arches development at the same days. Large vessels ventrally to the midgut was visible, these vessels connect the yolk sac with the primitive gut; in human embryos, this phenomenon happens at the beginning of the fourth week (Moore and Persaud 2008).…”

“…); cranial neuropore opened showing the fourth ventricle and nasal cavity, midbrain, cervical curvature and tail; the pharyngeal arches were distinct and limbs were developed; Pieri et al. () showed in dog and cats (1.7 cm) similar results in limbs, and Roballo et al. () described the pharyngeal arches development at the same days.…”

“…), and organogenesis and crown–rump together described by Pieri et al. () in domestic carnivores. They used common criteria such as length, weight, developmental time, pharyngeal arches numbers, extremities development and skin derivations to determinate mammal age.…”

“…The embryos and foetus were fixed in paraformaldehyde 4% (pH 7.4–0.1 m ) and routinely processed through paraffin and frozen embedding techniques as described by Pieri et al. () in dogs and cat embryos. The slides were analysed using microscope Zeiss KS400 (Carl Zeiss, Oberkochen, Germany), and images were captured by software axiovision LE (version 4.7.7, Carl Zeiss MicroImaging GmbH, Jena, Deutschland).…”

“…The gestation period can be estimated by many methods such as ultrasonography (Ali and Fahmy 2008), established the fetometry, crown-rump (Evans and Sack 1973), method already used in bovine (Assis-Neto et al 2009), dog and cats (Abreu et al 2011;Roballo et al 2013), and organogenesis and crownrump together described by Pieri et al (2015) in domestic carnivores. They used common criteria such as length, weight, developmental time, pharyngeal arches numbers, extremities development and skin derivations to determinate mammal age.…”