Schistosomus reflexus is a birth defect resulting in the malformation of the entire body. Calves with this condition are commonly not able to pass through the birth canal, and must be retrieved by c-section or fetotomy.
Calves which develop this condition are characterized by a failure of the body wall to close, resulting in a calf that is essentially “inside-out” with exposure of the abdominal organs. The skeleton is commonly malformed, with anomalies such as decreased number or fused ribs and vertebrae, crooked and improperly positioned limbs, and inversion of the spinal canal. Any number of gross defects have been described and are highly variable. The calf may be carried to term, and the first sign of a problem may be a dystocia in which the cow fails to make any progress towards delivery. Rectal palpation may detect a disoriented fetus.
No identifiable cause has been described for the condition, which is believed to occur spontaneously as a defect in embryologic development. Some data suggest a genetic susceptibility, but this has not been well defined.
The malformed fetus is not likely to be pulled by conventional methods, and must be removed from the uterus by fetotomy or cesarean section. Current opinions suggest that cows will bred back quicker when the fetus is extracted by fetotomy, however the complicated and irregular anatomy may require c-section to safely remove the fetus. Reports of live calves born twin to a schistosomus reflexus calf do exist, and will call for a c-section if the live calf cannot be delivered vaginally. Due to the suspicion of a genetic component, it may be advisable to remove the dam from the breeding herd.
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(PDF) K.W. Laughton, K.R.S. Fisher, W.G. Halina and G.D. Partlow. Schistosomus Reflexus Syndrome: A Heritable Defect in Ruminants. Anat. Histol. Embryol. 34, 312–318 (2005) Click to see the full PDF file: http://18.104.22.168/library/article/schistosomus-reflexus-syndrome-heritable-defect-ruminants
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(PDF) Whitlock, BK. Heritable Birth Defects of Cattle. Applied Reproductive Strategies Conference Proceedings Nashville, TN. 2010. Pp.146-153. Click the following link to view the full PDF file: http://126.96.36.199/library/article/heritable-birth-defects-cattle