Feelings of anxiety that make you tense and irritable

Two wolf packs that equally don't like each other, forced to work together due to the winter nearing rapidly. Prey is scarce, winds are cold, and teeth are bared. A sickness similar to tuberculosis and rabies starts getting passed throughout both packs, which seems to be sourced from prey as well as bodily fluids. There doesn't seem to be much you can do for the ill as some wolves will find out. Soon it becomes very apparent that younger and older wolves get more sick than middle aged wolves, and tend to succumb to the illness rapidly. The illness causes terrifying symptoms, such as foaming at the mouth, coughing blood, loss of appetite, confusion, and fever.