Chronic toxicity of dietary 2,3,7,8-tetrachlorodibenzo-p-dioxin to mink

Mature female natural dark mink (Mustela vison) were fed 0.0006 (control), 0.016, 0.053, 0.180, or 1.40 ppb 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for 131-132 d to ascertain the chronic toxic effects of TCDD in mi nk, inc luding reproduction. Consumption of the 1.4 ppb TCDD diet resulted in letha rgy, bloody stools, and 16.7% mortality. Final mink body weights were inver sely proportional to the dietary TCDD concentrations. Due to subnormal mink breeding, definitive effects of TCDD on mink reproductive performance were not ascertained; however, there were significant dose-dependent decreases in kit (young mink) birth weight and survival from birth to 3 w of age in t he groups that had reproduction. There were also significant differences in adult mink white blood cell counts, plasma total solids, serum iron, phosp horus, albumin, total protein, total CO2, cholesterol, osmolality, and anio n gap concentrations, and alanine aminotransaminase activity between the va rious dietary groups. During the latter stages alopecia and thickened, defo rmed, and elongated toenails were observed in the adult mink fed 1.4 ppb TC DD. At termination the mink fed 1.4 ppb TCDD had ascites, gastric ulcers, i ntestinal hemorrhages, depletion of adipose tissue, and mottled and/or disc olored livers, spleens, and kidneys. Focal lymphocytic meningitis in region of the olfactory bulb was present in 42% of the mink fed 1.4 ppb TCDD. The se results confirmed the high sensitivity of mink to TCDD and revealed a to enail abnormality not previously reported for mink fed TCDD.