Congenital hypothyroidism of dogs and cats: A review

Abstract

Congenital hypothyroidism is a rare and underdiagnosed congenital endocrine disorder in dogs and cats and the true incidence is unknown. The disorder may cause a range of clinical signs depending on the primary defect, which affect production of thyroid hormones; some cases present when adult. Hallmark clinical signs of congenital hypothyroidism are mental impairment and skeletal developmental abnormalities, resulting in disproportionate dwarfism; goitre may or may not be present. Documented causes of congenital hypothyroidism in dogs include deficiency of, or unresponsiveness to, thyrotropin-releasing hormone (TRH) or thyroid-stimulating hormone (TSH), thyroid dysgenesis, dyshormonogenesis and iodine deficiency. In cats, TSH unresponsiveness, thyroid dysgenesis, dyshormonogenesis and iodine deficiency have been confirmed. Adequate replacement therapy results in a successful outcome in the majority of cases, especially when started early in life, as permanent developmental abnormalities can be prevented. This review describes reported cases in dogs and cats, diagnostic investigation, and recommendations for treatment.

Bilateral femoral capital physeal fractures in an adult cat with suspected congenital primary hypothyroidism

“…Unfortunately, there is no test available to measure thyroglobulin antibodies in cats which would have delivered additional information [35]. Possible aetiologies of congenital hypothyroidism already reported in dogs and cats include defects of development, i. e. aplasia, hypoplasia, and ectopia, which could not be detected by diagnostic imaging in the present case, defects in thyroid hormone synthesis and iodine deficiency and excess [3]. Diagnosing hypothyroidism can be challenging.…”

Whole-genome genotyping and resequencing reveal the association of a deletion in the complex interferon alpha gene cluster with hypothyroidism in dogs

“…Excluding rare congenital hypothyroidism and other sporadic thyroid-related disorders, autoimmune hypothyroidism accounts for most cases in which this gland fails to produce sufficient amount of its specific hormones, i.e. thyroxine (T4) and triiodothyronine (T3) [11,12]. In the western countries, where the daily intake of iodine is sufficient, autoimmune Hashimoto's thyroiditis (HT) represents the major cause of human hypothyroidism [13].…”

Estudo Epidemiológico E Achados Laboratoriais De Cães Hipotireoideos Atendidos No Hospital Veterinário “Dr. Halim Atique”, Rio Preto, Sp, No Período De Janeiro De 2004 a Fevereiro De 2010

“…O hipotireoidismo é a doença endócrina que mais comumente afeta os cães (BOJANIĆ et al, 2011) e ocorre devido ao desequilíbrio em qualquer parte do eixo hipotálamo-hipófise-tireóide (MOONEY, 2011).…”