Ascites Syndrome Associated with Hypothyroidism in a Brahma Chicken: a Case Study and Review of the Literature

Abstract

Ascites syndrome (AS) in chickens represents a major cause of mortality and the most frequent metabolic-related cause of abattoir carcass condemnation in broilers. Susceptibility of broiler chickens to ascites is determined by a complex interaction between genetically-controlled factors (as high-rate metabolism and peculiarity of the cardiovascular system) and exogenous factors such as nutrition, and temperature. Endocrine imbalances, especially thyroid-gland dysfunctions, are currently regarded as key-elements in the development of AS. The current case represents the first spontaneous case of hypothyroidism (goiter) associated with AS in broilers, bringing additional arguments to the theory which claims the role of thyroid dysfunction in this syndrome. Further studies of spontaneous cases which must include assessment of the thyroid hormones need be performed in order to better understand the link between thyroid gland dysfunction and the cardiopulmonary changes in the context of AS in birds.

Case report: The first description of a thyroglossal duct cyst in a hen (Gallus gallus domesticus)

“…Goiter (thyroid follicular hyperplasia) with an enlargement of the thyroid gland can develop in birds. In the thyroid follicular hyperplasia (goiter), the thyroid follicles are diffusely enlarged and contain homogenous eosinophilic colloid but are lined by flat to low cuboidal follicular epithelial cells ( 25 ) and not ciliated epithelia as in the TDC. Salivary gland cysts (mucoceles) in birds were previously described in a spectacled owl ( Pusilatrix perspicillata ) ( 26 ) and consist of multilocular cysts lined by cuboidal epithelia containing mucus-rich fluid admixed with foamy macrophages and fewer heterophils.…”