Testing has confirmed that six free-ranging white-tailed deer from four Michigan counties have died from epizootic hemorrhagic disease.
The Michigan Department of Natural Resources said yesterday that another 150 likely cases have been reported over the past 15 days.
The viral disease is transmitted by a type of biting fly called a midge and can cause internal bleeding and fluid accumulation.
In severe forms of the disease, deer lose their appetite and fear of humans, grow progressively weaker, salivate excessively and finally become unconscious.
Infected deer often seek water to lower their body temperature and rehydrate, and then are found sick or dead near bodies of water.