Health effects in family pets and 2,3,7,8-TCDD contamination in Missouri: a look at potential animal sentinels.

In 1971, waste oils containing 2,3,7,8:tetrachlorodibenzodioxin (TCDD) were sprayed in Missouri for dust control. To determine if pets could serve as sentinels of human health risks associated with this contamination, we asked pet owners in a pilot study of exposed human populations about their pets' illnesses. Of 13 pets with owner-reported illnesses, 8 had potential TCDD exposures and 5 did not (p less than .05 by Mantel-Haenzel chi-square analysis stratified by age). Owner-reported illnesses in 2 of 8 illness categories were associated with TCDD contamination after adjusting for age. Although these findings suggest that pets in TCDD-contaminated areas may have greater health risks, the small sample size, unlikely pathologic groupings, and unconfirmed nature of the data fail to support a relationship between pet illnesses and possible TCDD exposure and thus make extrapolation to human populations inappropriate. The limited validity found for owner-reported pet illnesses should caution against using such data in future environmental health studies.