Microbiology of diarrhoea in young beef and dairy calves in Argentina.

Rotavirus, Cryptosporidium sp, and Salmonella spp. were investigated in the faeces of 452 diarrhoeic calves from 36 beef and 33 dairy herds. Animals surveyed were from a few days of age up to approximately 1 month of life. Enterotoxigenic Escherichia coli (ETEC) was studied in 212 calves, aged 15 days or less. The animals were from the Provinces of Buenos Aires (59% of the calves), Córdoba (18%), Santa Fe (16%), Entre Ríos (5%) and La Pampa (2%). A minimum of 4 calves were sampled on each farm. In beef calves rotavirus was excreted by 45.1% of the animals. Cryptosporidium by 30.5% and Sàlmonella serovars Arechabaleta, Livingstone, Panama and Typhimurium by 1.9%. In dairy calves Cryptosporidium was excreted by 29.6%, rotavirus by 23% and Salmonella serovar Dublin by 1.6%, ETEC was not detected in any calf. Rotavirus was the most widespread agent, detected in 32 (88.9%) beef herds and excreted by more than 50% of the calves in half of these herds. In contrast, rotavirus was only detected in 19 (57.5%) dairy herds and was excreted by more than 50% of the calves in 6 of these herds. Crytosporidium oocysts were identified in 27 (75%) beef and in 23 (69.7%) dairy farms. Salmonellosis due to serovar Dublin was associated with diarrhoea in 2 dairy herds. Concurrent infection with two or three agents occurred in 36 (8%) calves and 38 (55.1%) farms; the combination rotavirus-Cryptosporidium was found in 32 (6.9%) calves an in 33 (47.8) farms.