Causes of death and sex differences in survival times of pigs with untreated hereditary lymphosarcoma (leukemia).

The survival times from birth of 39 entire male Large White pigs with hereditary lymphosarcoma (L/S) were significantly shorter than those of 76 affected females. The survival times of 19 male castrates were for the most part intermediate between those for entire males and females. Analysis of the cause of death revealed that pigs with L/S (L/S-P) were more likely than pigs without L/S to die from colibacillosis, but this disease showed to sex predisposition. In uncomplicated deaths from L/S, weights of splanchnic lymph nodes, spleen, and thymus were greatest in females. The cell-mediated and humoral antibody responses of L/S-P were significantly poorer against 2,4-dinitrofluorobenzene (DNFB) and sheep red blood cells, poorer against skin homografts, but better against bovine serum albumin than those of healthy littermates. Healthy females had stronger DNFB reactions than did healthy males or castrates. Castrated L/S-P responded to DNFB better than did females and significantly better than did entire males.