Ronidazole toxicosis in 3 society finches (Lonchura striata)

A group of finches were accidentally overdosed with ronidazole, a 5-nitroimidazole used for treatment of trichomoniasis. Finches developed neurologic signs on the third day of treatment and were euthanized (or died). Three finches were submitted for necropsy. Focal necrosis of the cerebellar nucleus was seen in all 3 birds, as characterized by neuronal necrosis, vacuolation of the neuropil, gemistocytic astrocytosis, hemorrhage, and axonal swelling (spheroids) with demyelination. The liver from 1 finch was analyzed for ronidazole and its metabolite, 2-hydroxymethyl-1-methyl-5-nitroimidazole, by high-performance liquid chromatography-mass spectrometry. Ronidazole was detected in the liver tissue at 2,700 ng/g (wet weight), and 2-hydroxymethyl-1-methyl-5-nitroimidazole was detected at 140 ng/g (wet weight).