| herd characteristics and cow-level factors associated with prototheca mastitis on dairy farms in ontario, canada. | prototheca spp. are algae that cause incurable acute or chronic mastitis in dairy cows. the aim of this case-control study was the identification of cow- and herd-level risk factors for this unusual mastitis pathogen. aseptically collected composite milk samples from 2,428 milking cows in 23 case and 23 control herds were collected between january and may 2011. a questionnaire was administered to the producers, and cow-level production and demographic data were gathered. in 58 of 64 isolates, pr ... | 2012 | 22884347 |