The Effect of Total-Body X-Irradiation on Reproduction of the Female Beagle to 4 Years of Age

Female beagles exposed to either 100 r or 300 r (midline tissue dose in air) at puberty (351 plus or minus 8 days) were tested for reproductive ability by whelping two litters before 4 years of age. First litters were whelped at an average of 671 days and second litters at 1001 days of age. Conception rate compared favorably between treatments, and pup viability first and second litters from irradiated dams equaled or bettered that from controls. No differential causes of puppy mortality were discernible in the 297 litters totaling 644 pups. Secondary sex ratios were not significantly different between treatments; more males than females were whelped from irradiated dams, but more females survived to weaning age. The conclusion is that a female dog surviving total-body x irradiation at puberty will not suffer loss in fertility to 4 years of age. (auth)