Outbreak of sudden death in weaned calves on a New York dairy caused by Strongyloides papillosus

Abstract

S. papillosus are slender hair-like worms that have a predilection for the duodenum and proximal jejunum of ruminants. The third larval stage of S. papillosus penetrates the skin, often in the coronary band region of the limb, and migrates to the gastrointestinal tract where it matures to the parthenogenetic adult stage. Typically S. papillosus infection of calves in North America is associated with clinical signs of diarrhea, dehydration, anorexia, and weight loss or poor weight gain (Thamsborg et al, 2017).

Outbreaks of sudden death associated with heavy S. papillosus burden are rare and have only been reported in 2-5 month old calves in Japan (Taira and Ura, 1991). These Japanese outbreaks occurred in the summer, where common conditions included sawdust bedding, high environmental temperatures, and high humidity. Experimental studies revealed the sudden death of calves with heavy worm burdens to be preceded by cardiac arrhythmias for 1-2 days and ventricular arrhythmias leading to cardiac arrest (Tsuji et al, 1992). These researchers hypothesized that S. papillosus may produce a cardiotoxin that leads to cardiac arrest of infected calves.

S. papillosus has recently been implicated as the novel cause of an outbreak of sudden death in weaned dairy calves on a well-managed farm in New York State. The following report describes this first documented North American outbreak of sudden death in calves caused by S. papillosus.