Needle aspiration technique as a supportive tool for clinical diagnosis of anorectal atresia in calves.

Background: Early diagnosis and treatment of anorectal atresia, a common congenital abnormality in calves, are crucial for preventing complications and ensuring the animal's survival. Typically, newly born calves with this condition are present with an inability to defecate due to an absence of or an obstructed anal opening, often accompanied by abdominal pain and distension. History, physical examination, and radiographic imaging are frequently utilized diagnostic tools. This study aimed to evaluate the effectiveness of needle aspiration as a supportive diagnostic technique for anorectal atresia in bovine calves under field conditions and to assess its role in decision-making to proceed with surgical intervention.

Results: A total of 116 male calves, aged six hours to five days, were examined through clinical inspection, needle aspiration, and plain radiography. Clinical findings indicated that 62 cases had atresia ani, while 54 calves were diagnosed with atresia ani et recti. In cases without detectable swelling under the base of the tail, even with manually applied pressure on the abdomen, needle aspiration and radiographic findings showed positive results in 46.30% of calves. These cases were characterized by a radiolucent, distended rectal end close to the perineal skin surface (≤ 5 cm). Conversely, 53.70% of animals had negative aspiration results, with radiographic evidence of gas accumulation at the rectal end located > 5 cm from the perineal surface. Additionally, successful creation of an artificial anus at the perineum was achieved in cases with a rectal end near the skin surface. Whereas cases with a far rectal end more than 5 cm were subjected successfully to right flank laparo-typhlostomy.

Conclusions: Needle aspiration is a straightforward, non-invasive technique that proves highly valuable in facilitating diagnosis and guiding surgical decisions in calves with anorectal atresia, particularly in cases where bulging is not observed upon manual abdominal pressure. It is most effective when the rectal end is within five centimeters proximal to the perineal skin surface.