TG and cyclic hematopoiesis: CH has been described in different species, including humans, dogs, and cats, and the clinical signs are closely related to a failure in the physiological functions of thyroid hormones, related to poor muscle and brain development, alterations in energy balance, developmental abnormalities such as disproportionate dwarfism, large head, flat face, smaller neck, body, and extremities, delayed tooth eruption, epiphyseal dysplasia, and delayed physeal closure, as well as the presence of palpable bilateral mobile goiters, bradycardia, hypothermia, swollen tongue, and flaccid muscle tone [2–4].