Personnel have now ruled out calcium deficiency, chronic wasting disease, bacterial and common viral infections, tick paralysis, meningeal and carotid artery worm as causes. Mercury poisoning, selenium toxicity, many of the common plant toxins, a variety of metals and salt, nitrate and sulfate poisoning have also been eliminated.
Another thing officials have dismissed is that someone ran the animals to death. Reed said that theory is pretty much off the table.