Spontaneous Thyroiditis in the Obese Strain of Chickens: III. The Effect of Bursectomy on the Development of the Disease¹ Free

The Obese Strain (OS) of White Leghorn chickens reveals spontaneous chronic thyroiditis which is characterized by infiltration with mainly large mononuclear cells, the occurrence of a great number of germinal centers in the thyroid glands, and the presence of circulating thyroglobulin autoantibodies.

Bursectomy on day of hatching resulted in a significant decrease in the incidence and severity of the disease when the chickens were examined 7 weeks after hatching. This decrease was paralleled by the absence of precipitating and hemagglutinating thyroglobulin antibodies in most cases. Bursectomy in ovo on day 19 of incubation had an even more pronounced suppressive effect on the development of the spontaneous, chronic thyroiditis and the presence of circulating thyroglobulin antibodies. Sham bursectomy had no effect. It is concluded that bursa-dependent lymphoid cells play a major role in the development of spontaneous, chronic thyroiditis in OS chickens.