CASE NOTES
A series of AWKD events — chronic glomerulopathies in Australian White Lambs
Emily Winkenwerder and Pedro Pinczowski, Elizabeth Macarthur Agricultural Institute, Menangle, NSW
Posted Flock and Herd November 2024
Last year, the Elizabeth Macarthur Agricultural Institute (EMAI) received a two-month-old Australian White lamb for post-mortem investigation after a brief clinical history of getting sick, lethargy, moving away from the flock, and death within 12 hours of the onset of clinical signs. This case became the latest addition to a collection of cases with suspected inherited congenital renal disease in Australian White lambs, colloquially referred to as Australian White Kidney Disease (AWKD).
Since 2021, there have been multiple reports of rapid to sudden death cases in two-week to two-month-old Australian White lambs on six unrelated properties in various locations around NSW. Mortality rates of 1.07-10% were reported with lambs presenting with a variety of signs including general unwellness, recumbency, lethargy, drooping ears, respiratory distress, inappetence, bruising, and neurological signs (blindness, trouble swallowing, head pressing, shaking, seizures, stargazing). In total, 10 lambs were necropsied with findings affecting predominantly the kidneys, including miliary renal cortical haemorrhages, enlarged kidneys and variable degrees of bilateral hydronephrosis without signs of obstruction. In addition, some cases reported pulmonary changes and intracavity effusions. When conducted, haemogram and biochemical results showed changes consistent with renal failure.
Histopathology consistently revealed severe, chronic crescentic glomerulonephritis with glomerular haemorrhages, without significant changes in other tissues. These findings suggest a primary glomerulopathy. A variety of ancillary testing (e.g. bacterial culture, PCR, mineral profile) were performed excluding infectious and nutritional causes. AWKD is a suspected emerging inherited or congenital renal disease. Further investigation is currently underway to determine the pathogenesis.