Excerpt from FINAL of Dr. Bolton’s work.
The study is currently completed and all data statistically analyzed and interpreted. The entirety of the project (results and conclusions) has been compiled into a manuscript and is under review currently by the Journal of Veterinary Internal Medicine.
Total T4 is the most common hormone measured in dogs suspected of hypothyroidism and is low in cases of this disease. It can also decrease in dogs with nonthyroidal illness, frequently resulting in an inappropriate diagnosis of hypothyroidism and unnecessary thyroid hormone supplementation. The results of this study have demonstrated that total T4 normalization occurs in 80% of cases by hospital discharge and 96% of cases by the 2-week follow-up. Thus, in dogs diagnosed with acute nonthyroidal illness having a low total T4, rechecking this hormone 2 weeks following nonthyroidal illness resolution is likely to result in an accurate assessment of thyroid hormone status for the patient (i.e., normal total T4).