Chronic mastitis caused by Candida maltosa in a cow.

In general, bovine mastitis due to candidial infection is acute or transitory, and recovery is spon taneo~s .~ .~ Various species of Candida have been isolated from cases of bovine mastitis; however, the relationship between lesions and Candida is unknown. Although Sutka6 isolated Candida guilliermondii from clinically chronic mastitis of cows, the lesions associated with the fungus were acute. This study describes the pathologic findings of chronic mastitis caused by Candida maltosa in a 5Ih-year-old Holstein-Friesian cow. After parturition, the cow retained the placenta, which could not be removed. She had a fever (40.0-40.5 C) from 6 days after parturition and was affected with mastitis within 1 week. The cow was treated with an intramuscular injection of 19,100,000 units of penicillin and 100 international units (IU) of oxytocin and intramammary infusion of 1,500 mg of streptomycin and 800,000 units of nystatin. The mastitis was characterized by swelling and induration but involved only one quarter of the udder. This mastitis was progressive. Because the treatment had no apparent effect, she was euthanatized 24 days after parturition. Samples of the affected quarter of the mammary gland and the supramammary lymph node were removed, fixed in 10% neutral buffered formalin, and forwarded to our department. The cut surface of the gland had multiple, small (0.8 mm in diameter) to large (1 .O cm in diameter), irregular necrotic foci surrounded with granulation tissue. The supramammary lymph node was markedly enlarged (approximately three times normal). Only C. maltosa was isolated on the microbiologic examination of the milk collected 4 days after the onset of fever (1 4 days before necropsy). The species was identified on the basis of the following morphologic and growth characteristics:' 1) the absence of true hyphae chlamydoconidia, arthroconidia, and ascospores, the presence of pseudohyphae, and the fermentation of D-glucose and sucrose; 2) grew when the following were added to the media: D-galactose, succinate, 50% sucrose, maltose, aptrehalose, L-sorbose, D-mannitol, glycerol, citrate, melezitose, D-xylose, ribitol, DL-lactate, and 2-keto-D-gluconate; 3) did not grow when the following were added to the media: cellobiose, melibiose, L-rhamnose, galactitol, erythritol, D-arabinose, raffinose, D-ribose, 60% sucrose, lactose, myo-inositol, and L-arabinose; 4) grew in vitamin-free media and did not grow at 42 C or when 0.1% cycloheximide was added to the media; and 5 ) did not hydrolyze urea, assimilate potassium, or grow in dextrose-yeast peptone water. Histologically, mammary lesions were divided into two types: extensive suppurative inflammation with necrosis, and giant cell formation. In the former lesions, numerous fungal elements in the central areas of necrotic foci were surrounded by numerous neutrophils and granulation tissue (Fig. I). In the latter lesions, many giant cells were observed within involved alveoli and intralobular ducts. The giant cells had engulfed fungal elements (Fig. 2) that occasionally were degenerative. The basement membrane of the involved alveoli and ducts was intact in the initial lesions, while it was destroyed in the advanced ones. These findings suggest that the fungi invaded intraductally.