The Galgothians believed the Dramos responsible for the sickness that visited them every year. The Dramos was hunted down and killed to near extinction for its blood which they believed held a cure.
The truth was that the sickness visited and coincided with the breeding pattern of the Demnos. It was the tears of these fearsome beasts that offered the cure. Thanks to the Tenth Doctor's intervention, these two races began to live a peaceful and supportive co-existence with the female Dramos able to rear her young safely. (COMIC: Blood and Tears)