Pathological Studies on Mucormycosis of the Forestomach and Abomasum in Ruminants : A Report on Six Cases Complicated with Candidiasis or Pulmonary Aspergillosis

Mucormycosis of the forestomach and the abomasum was found in two beef bullocks, three cows and a ram. Clinical examination revealed various symptoms due to anomaly of the alimentary canal in three of the bovine cases antemortem. The others were postparturient downer and acute necrotic mastitis cow respectively. Postmortem examination disclosed three stages of lesion: an acute early stage of lesions of marked cirtulatory disturbance with necrotic suppurative changes, a subacute middle stage of severe necrosis with suppuraitve changes, and a chronic late stage of granulomatous lesions. Vascular affinity of fungal hyphae was very common in all the lesions, except those of the chronic late stage. Mucormycosis was associated with disseminated miliary nodular Aspergillus pneumonia in one of the bovine cases and with candidiasis in the ram. Discussion was made on the importance of the histopathological examination in mycotic diseases. Rumen acidosis due to excess feeding with grains seemed to be a main predisposing factor in most of the cases, although no concurrent lesions detected were negligible.