Thyro-Tabs Canine contain levothyroxine sodium, USP. L-thyroxine is used in dogs for correction of conditions associated with low circulating thyroid hormone (hypothyroidism). Each Thyro-Tabs Canine Tablet provides synthetic crystalline levothyroxine sodium (L-thyroxine). The initial recommended daily dose for L-thyroxine is 0.1 mg/10 lb. body weight as a single dose every 24 hours, or as a divided dose every 12 hours.