Cardiomiopatia dilatada congestiva, refratária à terapia convencional associada ao hipotireoidismo e hiperadrenocorticismo em um cão - relato de caso.

Abstract

Hypothyroidism and canine hyperadrenocorticism are multisystemic diseases with a wide range of clinical signs that affects middle-aged animals. In hypothyroidism, a decrease in the circulating level of thyroxine influences the electrophysiological, systolic and diastolic functions, as well as cardiac rate and output. Hypercortisolism in patients with hyperadrenocorticism (HAC) may result in accumulation of myocardial lipids along with systolic and diastolic impairment. In this context, the objective of this study was to report and relate the cardiovascular changes observed in a dog with hypothyroidism and hyperadrenocorticism examined at the Small Animal Medical Clinic (CMPA), at the Veterinary Hospital, UFCG, Patos-PB. A canine, 11-year-old Cocker Spaniel had been diagnosed with hypothyroidism upon completion of his second year of life. Since then, he has been accompanied by Veterinarians at CMPA. To identify the pathologies, the veterinary team performed physical and clinical exams, hemograms, biochemical and electrolytic evaluations, hormonal dosages, ultrasound, X-ray, Doppler echocardiogram and electrocardiogram. Upon physical examination, a bulging abdomen with signs of ascites, cough and dry seborrhea were observed. Tachycardia, tachypnea and hypertension were evidenced during clinical follow-up. High concentrations of the enzymes alkaline phosphatase (557.9mg/dL) and alanine aminotransferase (228.9 mg/dL) were observed. Dosage of cortisol via low dose dexamethasone suppression test resulted in conclusive values for pituitary-dependent HAC. In the Doppler echocardiogram, a decrease in left ventricular shortening fraction and ventricular ejection fraction were observed. After treatment for hypothyroidism (levothyroxine sodium), dilated cardiomyopathy (digoxin, pimobendam, inalapril and furosemide) and HAC (trilostane), parameters in the Doppler echocardiogram were observed in the normal range for the species. This case report establishes information about the importance of the diagnosis, treatment and follow-up of patients with hypothyroidism by the Veterinarian.