Hipotiroidismo primario en canino de raza beagle de 8 años de edad: reporte de caso.

Abstract

Canine hypothyroidism is a common condition, affecting between 0.2% and 0.8% of the canine population. This disease can be primary, representing 95% of cases, usually caused by autoimmune lymphocytic thyroiditis or idiopathic atrophy of the gland. Secondary hypothyroidism is less frequent and is due to problems in the pituitary gland, affecting TSH production (Mora et al., 2021.) Clinical symptoms of hypothyroidism include lethargy, weight gain, dermatological problems such as alopecia and dry skin, as well as neuromuscular and cardiovascular symptoms. These symptoms can be nonspecific, which makes it necessary to differentiate it from other diseases such as diabetes mellitus and Cushing's syndrome. Diagnosis is based on the measurement of TSH and free or total T4 levels, with an increase in TSH and a decrease in T4 being indicative of hypothyroidism The main treatment for hypothyroidism is the administration of thyroxine. The recommended starting dose is 20 micrograms per kilogram of body weight, adjusted according to the patient's response. Dogs are expected to show improvements in activity and mood in 1 to 2 weeks, and a reduction in more severe symptoms in 5 to 6 weeks, with full recovery in 6 to 8 weeks. It is crucial to monitor T4 and TSH levels between weeks 4 and 6 to adjust the dose and avoid thyrotoxicosis, a condition of excess thyroid hormones that can cause symptoms such as hyperactivity and weight loss (Monsalve, 2020.)