Acute toxicity of penicillic acid and rubratoxin B in dogs.

The effect of intraperitoneally administered penicillic acid, a mycotoxin produced by several species of Penicillium and Aspergillus, on female dogs of mixed breeding was determined by serum tests, by observation of clinical signs and survival times, and by evaluation of gross and microscopic lesions. Combination studies employing penicillic acid and a second mycotoxin, rubratoxin B, also were undertaken. Post mortem examination disclosed hemorrhaging of the serosal surfaces of the abdomen of dogs receiving penicillic acid. The most significant histologic change observed in penicillic-acid-treated dogs was congestion and dilatation of hepatic sinusoids. Extensive hepatic changes of the liver were noted only in the dog receiving 20 mg/kg penicillic acid. There was no evidence of parenchymal necrosis in any of the liver samples examined from animals given penicillic acid. A predominently peripheral lobular depletion of glycogen in parenchymal cytoplasm also was seen in liver sections from animals exposed to penicillic acid. Although slight decreases in lactic dehydrogenase were observed, no trends were detected in the several blood enzymes and serum constituents examined that could be specifically related to penicillic acid intoxification. Glutamic-oxaloacetic transaminase, lactic dehydrogenase and alkaline phosphatase activities and survival time varied in relation to duration of exposure and total dose of rubratoxin B administered. The lesions in animals injected with 1.0 mg/kg rubratoxin B consisted of mild hepatic necrosis and degenerative changes in renal tubular epithelium. An additive effect due to the combined administration of penicillic acid and rubratoxin B was observed only by an elevation in serum sodium and chlorine levels.