Perosomus elumbis, cerebral aplasia, and spina bifida in an aborted thoroughbred foal.

The research article covers a case of perosomus elumbis, a rare congenital disorder, in an aborted thoroughbred foal. This disorder, commonly associated with spinal, urogenital, and intestinal defects, is noted here with additional abnormalities like cerebral aplasia, spina bifida, and fused urogenital and intestinal tracts.

Perosomus Elumbis and its Features

• Perosomus elumbis is a rare birth defect commonly observed to affect the lumbosacral spinal cord and vertebrae.
• Besides these, it often induces malformations in the urogenital and intestinal tract.
• Arthrogryposis, a condition that causes joint contractures, is frequently associated with this anomaly.

The Case Study of the Thoroughbred Foal

• This paper documents the first instance of a Thoroughbred foal developing perosomus elumbis.
• The anomaly manifested numerous unusual conditions.
• These included cerebral aplasia with meningocele (a type of spina bifida where membrane protrudes through the vertebrae), cranioschisis (a condition where the skull doesn’t fully close), spina bifida, and a fused urogenital and intestinal tracts lined by a cutaneous mucosa without uterine glands.
• The foal also presented atresia ani, a condition where the anus is closed or absent, and arthrogryposis of the hind legs.

Investigations and Findings

• Immunohistochemistry tests on the remnants of the brainstem found normal levels of GFAP, S-100, vimentin, NeuN, doublecortin, and neurofilament.
• Pathogenic bacteria or equine herpesviruses one and four, potential causes of such anomalies, were ruled out through microbiological investigation and PCR.
• The study suggests the observed malformations could have resulted from a severe developmental disturbance during the formation of the neural tube, which may have also distorted the surrounding mesoderm.
• However, the specific triggers of this dysorganogenesis remain unclear.

Speculated Causes of the Defect

• Possible causes of the defect could be inherited chromosomal mutations, exposure to various xenobiotics, or metabolic issues in the mother mare.