Intestinal atresia and stenosis: a review comparing its etiopathogenesis

Two theories were proposed originally to describe the development of congenital intestinal atresia. The theory of imperfect recanalization, the theory of vascular insufficiency, and studies which have been performed to validate each of these theories were reviewed. Specific causes of the development of vascular insufficiencies in different species were reviewed if literature was available. In utero vascular accidents have been incriminated as the major cause of congenital intestinal atresia distal to the duodenum. There was relatively little evidence to show that intestinal atresia is inherited in any species. Duodenal atresia may be caused by either an embryologic defect for which there is some evidence of inheritance or by a vascular accident. The pathogenic mechanism for intestinal atresia may be similar in most species.     

Intestinal atresia and stenosis: a review comparing its morphology

A review of the literature on intestinal atresia of domestic animal species and humans was done. The 5 types of intestinal occlusions described in human infants are atresia type 1, atresia type 2, atresia type 3, stenosis, and the "apple peel" or "Christmas tree" deformity. The intestinal defects described in domestic animal species such as the bovine, equine and porcine are similar to those of human infants. The "T-formation", an intestinal defect of the bovine resembling atresia type 3, and rectal stricture, an acquired intestinal defect of the porcine resembling stenosis, were described recently. Intestinal atresia is similar in several species and these similarities raise the questions as to whether the pathogenic mechanism and possibly etiologies of intestinal atresia are similar in these species.     

Fetal bladder outlet obstruction in a stillborn bovine fetus

A stillborn bovine male fetus with abdominal distention, arthrogryposis and atresia ani was presented for diagnostic evaluation. At necropsy, this fetus had a large amount of ascites, urachal obstruction and marked bladder distention. The ventral surface of the bladder had ruptured and attached to the abdominal wall by fibrinous adhesions. There was bilateral hydronephrosis with moderate pelvic dilatation and cortical attenuation. The rectum was filled with meconium but the anus was imperforate. The right forelimb was contracted. The cause(s) of these abnormalities could not be determined; however, we believe that developmental abnormalities during embryogenesis may be the result of chromosomal abnormalities.     

Sarcocystosis in an aborted bovine fetus

Sarcocystosis was diagnosed in an aborted bovine fetus. Immature and mature schizonts of Sarcocystis were disseminated in the vascular endothelium of all organs, but especially the brain. Microscopic granulomas, focal gliosis, and petechial hemorrhages in the neuropil were scattered in the brain. Multifocal collections of mononuclear cells were observed in the kidney, liver and heart. Organisms in sections of frozen tissues were demonstrated by immunofluorescent techniques to be Sarcocystis.     

Muscular pseudohypertrophy (steatosis) in a bovine fetus.

Muscular pseudohypertrophy was diagnosed in the cervical musculature of a full-term crossbred Simmental fetus delivered by fetotomy. Only head and cervical regions were submitted for pathologic examination; the rest of the fetal body was reportedly normal. The neck musculature of the fetus was markedly deformed by 23 cm and 18 cm in diameter, firm, spherical masses that consisted of enlarged and pale left splenius and right serratus ventralis cervicis muscle, respectively, covered by intact skin. Additionally, lipomatous masses were present within the cervical vertebral canal, compressing the spinal cord. Microscopically, the prominent muscular enlargement was due to massive adipose and fibrous connective tissue replacement of atrophic muscle. Focal myelodysplasia and astrocytosis affecting the grey matter was detected in the mid-cervical region of the spinal cord, accompanied by degeneration in the ascending and descending tracts of the remaining cord segments. Abnormal spinal cord development as a result of severe spinal cord compression by the lipomatous masses within the spinal canal leading to replacement of muscle by fat and fibrous tissue was considered to be the cause of the muscular malformation in this fetus.     

Chromosomal trisomy in an anormalous bovine fetus

This case report describes an anomalous male fetus of approximately six months gestation with abnormal karyotype containing an extra metacentric chromosome of medium size. The fetus had severe phenotypic abnormalities including anasarca, eye malformations, cardiac hypertrophy, pulmonary hypoplasia, adrenal dysplasia, and an umbilical hernia.     

Schistosoma reflexum in a female bovine fetus with synaptonemal complex abnormalities

In this study we present mitotic- and meiotic investigations in an anatomical abnormal bovine fetus. The abnormality could be classified as "schistosoma reflexum", which was never described in fetuses in the literature. In the mitotical chromosome preparations from fibroblast cultures the examined fetus showed no chromosomal difference in comparison to the standard synaptonemal complexes (SC) which were prepared from the fetus at the age of 92 days post coitum. In the SCs from the abnormal fetus 43.75% of the investigated cells showed abnormalities such as "loop," "nonhomologue pairing" and "multivalency" in the pairing behavior of the chromosomes. In comparison, less than 5% of the cells in normal embryos showed such abnormalities.