Figure 6. Intranasal challenge of adult BALB/c mice with cowpox virus (Brighton red).

A. Female BALB/c mice 14–16 weeks old were anesthetized with Ketamine / xylazine intraperitoneal. Eight mice per group were challenged with indicated doses of cowpox virus introduced into one nostril in a total volume of 5 µL. Mock challenged mice were anesthetized and given diluent intranasally. Mice were monitored daily for weight loss. Mice that lost more than 20% body weight were euthanized. Statistics shown are in comparison to mock challenged mice. B. Challenged mice were also monitored daily for clinical signs of illness. 0 indicates no clinical signs of illness; 1 indicates slight ruffling of fur; 2 indicates moderate signs of illness including ruffled fur, decreased activity, and conjunctivitis, 3 indicates severe signs of illness including ruffled fur, lethargy, labored breathing, hunched posture, and noticeable weight loss; and 4 indicates non-responsive or moribund. The number of surviving mice per group of 8 are noted with *.