A disease of cows characterized by swelling of the vulva, acute inflammation of the vaginal mucosa, accompanied by a more or less profuse mucopurulent exudate is described. After the acute inflammation subsides the mucosa becomes studded with tiny, round, raised, red nodules which persist 2 or 3 months or longer. The acute lesion consists in necrosis of the epithelium and accumulations of leucocytes and round cells in the edematous submucosa. The nodules in the later stages are made up of densely packed masses of lymphocytes in the submucosa which force the epithelial layer outward.
A Gram-negative bacillus with tiny polar granules was found in the exudate. It measures I to 2µ in length and stains with difficulty. The organism was obtained in pure culture by inoculating the exudate into tubes of slanted agar to which defibrinated horse blood had been added. Growth occurs only in sealed tubes. The organism possesses slight pathogenicity for guinea pigs. When freshly isolated cultures were introduced into the vagina of heifers or young calves, acute inflammation resulted which terminated in the characteristic granular stage of the disease.