Types of canine hormonal dwarfism through case reports

Abstract

Background. Hormonal dwarfism refers to a group of rare endocrinopathies characterized by a growth disorder generally due to an isolated or multiple deficiencies of anterior pituitary hormones and it may present as different clinical presentations including proportionate and disproportionate forms. Objectives. The aim of this work is to describe the different types of hormonal dwarfism in dogs through four clinical cases, and to report pituitary dwarfism for the first time in a breed of dog endemic to the Canary Islands. Clinical cases. This report describes four clinical cases of dogs between 3 and 8 months of age presenting with stunted growth. In two cases, pituitary dwarfism or growth hormone deficiency was diagnosed by clinical signs such as proportionate dwarfism, and measurement of serum IGF-1 concentration which was below reference range. One animal was treated with medroxyprogesterone acetate while the other animal was treated with proligestone. In another case, congenital central hypothyroidism was diagnosed by clinical signs such as disproportionate dwarfism, laboratory findings (non-regenerative anemia and dyslipidemia), radiographic findings such as delayed epiphyseal ossification or epiphyseal dysgenesis and low levels of thyroid (thyroxine) and pituitary (thyrotropin) hormone concentrations. This dog received a life-long treatment with levothyroxine sodium. Finally, the remaining animal presented combined pituitary hormone deficiencies resulting in panhypopituitarism and concurrent diabetes insipidus, consequently treatment was initiated to restore all hormone deficiencies: proligestone for pituitary dwarfism, levothyroxine sodium for central hypothyroidism, desmopressin for diabetes insipidus and prednisone for secondary hypoadrenocorticism. Conclusions. Hormonal dwarfism is a diagnostic challenge for veterinary clinicians as it may occur with different hormonal deficiencies and different clinical presentations as described in these four clinical cases. To our knowledge, this work includes the first description of pituitary dwarfism in a breed of dog endemic to the Canary Island of El Hierro, the Hierran Wolfdog.