We describe two unusual cases in sheep of subclinical mastitis caused by Streptococcus parasanguinis . Ovine mastitis represents a major sanitation and economic problem for both milking sheep farmers and the sheep-milk cheese industry because it reduces milk production and quality.
Many microorganisms produce asymptomatic, or subclinical, mastitis in milking sheep.
Therefore, the excretion of S. parasanguinis at relatively high concentrations in milk from apparently healthy sheep is of concern. Indeed, its presence in certain dairy products, such as nonpasteurized handmade cheeses, may pose a health risk in persons with predisposing heart lesions. After 48 hours of incubation at 37 C under aerobic conditions on Columbia blood agar, pure cultures of a -hemolytic colonies were recovered from both milk samples. The isolates are clinically important because both sheep fit the criteria for subclinical mastitis and the isolates were recovered in pure culture. Both isolates had an identical biochemical profile, which did not correlate with any of the species identified with the ID 32 multisubstrate strip.