[A case of mastitis caused by streptococcus viridans biotype IV (author's transl)].

A case of clinical bovine mastitis caused by infection with Streptococcus viridans, biotype IV was reported. Of a dairy herd of twenty-three cows, three animals were severely affected with clinical mastitis of at least two quarters in each cow. Streptococcus viridans, biotype IV, in pure culture was subsequently isolated on two occasions from eight quarters of these cows. Following experimental infection with the isolated Streptococcus viridans in a normal lactating cow, mastitis appeared with symptoms very similar to those observed in the spontaneous case. The organism cultured four days after infection, was identified as being the same organism used to induce infection. It is concluded that Streptococcus viridans could be pathogenic for the bovine mammary gland probably for other species.