The Effect of Hypothyroid Function Function on Canine Behavior
From the article:
They sleep more, seek out heat sources, and show reduced scenting, hearing and visual acuity. While these signs might be attributed to advancing age or even cognitive dysfunction, they will resolve with treatment of the hypothyroidism along with the behavioral problems.
Behaviors are lost from one training session to the next. Owners often describe these dogs as appearing to have AD/HD. These dogs may become fixated on one activity – such as playing Frisbee – and only value their owners’ presence for providing this.
Deficiencies of thyroid, adrenal cortex and sex hormones impair learning and the ability to store memories and behave normally. The adrenal hormones are directly involved in learning and behavior, while thyroid and sex hormones appear to modulate learning, memory and behavior at a higher level (Fedotova 2000). Hypothyroidism often reduces cortisol clearance. Conversely, glucocorticoids inhibit TSH release in response to thyrotropin releasing hormone (Otsuki et al 1973), reduce conversion of T4 to T3 (Chopra et al 1975) and have direct effects on the thyroid gland itself (Kemppainen et al 1983), so that stress could further diminish the function of a suboptimal thyroid. The thyroid-adrenal axis could be expected to affect behavior at all levels.