Titya abstersa-associated gastrointestinal disease in calves: A report of a natural outbreak

In the summer of 2023 in southern Brazil, there was a fatal outbreak of acute gastrointestinal disease in calves that ingested Titya abstersa caterpillars. The outbreak affected 6 of the 40 calves raised in an extensive system, with a mortality rate of 15%. The clinical signs included anorexia, hypersalivation, ruminal bloat, fever (39.8-40.5°C), polydipsia, and gastric reflux. Death occurred within 24 to 48 hours after the onset of the clinical signs. Macroscopic and microscopic findings revealed necrotic rumenitis, reticulitis, esophagitis, and longitudinal and transverse sections of golden structures with backward-facing barbs, consistent with intralesional caterpillar setae. This study aimed to characterize the clinical, epidemiological, and pathological aspects from the necropsies of 3 affected calves. To date, there have been no similar reports regarding the ingestion of T. abstersa caterpillars.