Assessment of circulating total and free iodothyronines’ patterns in adult ovine and caprine specimens: influences of endemic goiter area

North-eastern Sicily is an area with iodine deficiency disorders occurring in both humans and animals. The aim of this study was to test the influences of an endemic goitre area on iodothyronine ranges and their pattern in adult ovine and caprine specimens stabled in different locations of Sicily, taking into account the different sexes. A total of 48 Comisana sheep and 51 Maltese goats was studied. The sheep included 10 females and 6 males stabled in a non-endemic goitre area (farm A: control group), and 16 females and 16 males stabled in an endemic goitre area (farm B: observational group). The goats included 6 females and 13 males stabled in a non-endemic goitre area (farm A: control group), and 16 females and 16 males stabled in an endemic goitre area (Farm B: observational group). The results showed lower T3 and higher fT4 (P<0.0001) levels in female and male sheep, and higher T4 levels in males (P<0.0001) stabled in farm B than in farm A. In comparison to farm A, goats stabled in farm B showed higher fT3 (P<0.0001) levels; males stabled in farm B showed lower T4 levels (P<0.0001), and females showed higher fT4 levels (P<0.0001). Significant effects of sex and of endemic goitre area on the total and free iodothyronines of sheep and goats were observed. The obtained data showed that an endemic goitre area for humans is not necessarily the same for ovine and caprine species, which seem to be able to adopt an adaptive strategy without presenting any clinical signs of thyroid disorders.