Thyroid histological changes in lambs from iodine-supplemented and untreated ewes.
OBJECTIVE
To identify the histological changes in the thyroid associated with subclinical goitre.


METHODS
Thyroids were histologically examined from lambs that died within 24 hours of birth in a trial to investigate the effect of iodine supplementation to Merino ewes on perinatal mortality.


RESULTS
Thyroids with follicles depleted of colloid, infolded and lined by columnar epithelium are indicative of hypothyroidism. These findings can occur in thyroids considered to be in the normal weight range of less than 1.3 g.


CONCLUSIONS
Thyroid histological changes are a useful aid in diagnosing subclinical goitre.
Clark
R G
RG
Labnet Invemay, Private Bag 371, Mosgiel, New Zealand.