| cost of mastitis and its prevention in four dairy cattle herds on st croix, us virgin islands. | nonclinical mastitis in the dairy herds on st croix, us virgin islands, represents a prevalent (97%) and severe problem (44% of quarters had california mastitis test results of 2 or 3). streptococcus agalactiae (26%) and staphylococcus aureus (22%) were the most prevalent pathogens. more than half (54%) of all organisms isolated and tested for resistance were resistant to ampicillin and benzyl penicillin; 29% were resistant to trimethoprim/sulfadiazine. estimates of the loss of milk production s ... | 1989 | 2656608 |