2002 Volume 55 Issue 4 Pages 235-238
To investigate the role of the thyroid function in the development of hypothermia in dogs, concentrations of serum total thyroxine (tT4), free thyroxine (fT4), and the canine thyroid-stimulating hormone (cTSH) were determined in 12 hypothermic dogs on Hokkaido. On the basis of clinical signs and serum tT4 concentrations, the dogs were divided into 3 groups of 4 dogs each: A) hypothyroidism, B) euthyroid syndrome, and C) nonlowering of thyroid hormones. Except in the case of group A, no consistent tendencies were observed in underlying diseases [bronchitis, canine distemper, liver disorder, heart failure, renal failure (2 cases), and no underlying diseases (2 cases)]. All 4 of the dogs in the hypo-thyroidal group showed a lowering of the fT4 level. In 2 dogs, in group B, however, fT4 decreased, and cTSH was in the low-normal range. These results suggest that measurements of fT4 and cTSH can be useful in examining hypothermic dogs.