Sex Hormones and Lymphomatosis in Fowls. ∗

Abstract

We have previously reported 1 upon the occurrence of lymphomatosis in 26 of 52 white leghorn capons and its absence in 66 slips of the same group of 118 birds. However, only 19 of these slips were older, when sacrificed, than the youngest bird (256 days) that developed the disease. There were 10 cases of diffuse hepato-renal lymphomatosis (big livered series), 7 of lymphosarcoma, 8 of lymphoma of bursa of Fabricius and 1 leukemia. The significant finding is that we have not seen lymphomatosis develop under our conditions in a bird with spontaneous comb growth. These observations suggested that the presence of a functionally active fragment of testis may have inhibited the development of the disease—possibly because of the production of sex hormones.

The relation of sex to the incidence of lymphomatosis has not been studied and for obvious reasons. Oakley 2 is the only author to refer to it but gives no data—merely stating that he has the impression it is more common in females and in the breeds kept for egg laying. Data on the sex incidence of leukosis in mice also are lacking.

The present experiment includes 41 white leghorn male castrates of the same age, divided into 3 groups as follows: (1) 12 birds, each receiving 1 mg estradiol dipropionate weekly, (2) 12, each receiving testosterone dipropionate in variable amounts twice weekly, and (3) 17 controls. Injections of these hormones were started on June 18, 1940, and they are still being given to the survivors. To date (Jan. 15) 4, or 33 1/3%, of the androgen group, 7, or 58%, of the estrogen group, and 4, or 23%, of the control group have died of lymphomatosis. The youngest (receiving estradiol dipropionate) was 201 days old and the oldest to date, 319 days.