The Dogs Are Tested For Cancer
One of the most common effects of long-term exposure to radiation is cancer. Identifying dogs who have tumors, as well as cataracts and some other malformations, helps rule out those who have absorbed the highest levels of radiation. These dogs are not healthy enough to be adopted, especially adopted out into the United States.
The presence of cancer is an indicator that the dog has suffered extensive genetic damage and may also have a disrupted microbiome inside its gut. The dogs are sedated and observed for signs of cancer and other life-inhibiting effects of radiation.