On a Sunday evening last July, Flora Gichonge was walking with her friends to church near the village of Gesarya, Tanzania. Suddenly, they were attacked by something hellish: A rabid dog, foaming at the mouth, charged out of the dense bushes lining the dirt road. "We tried to run away, in fear," the 25-year-old recalls. But she tripped and fell. The dog lunged and bit her in the backside before her friends drove it away by throwing stones.