ENCAMPMENT --Three of four elk captured alive but suffering from a mystery illness that were treated with a regimen of vitamins, antibiotics, and minerals have now died or been euthanized, Wyoming Game and Fish Department veterinarian Dr. Walt Cook said Monday.

Necropsies on two additional animals have been completed, but analysis of tissues has not been concluded so game officials remain baffled about why more than 290 elk have died, including another nine found in the field by wildlife managers over the weekend.

The discovery of the additional nine elk leaves officials "disappointed" because last week they believed the herd had passed the point where additional animals would become ill.

In all cases the elk seem basically healthy but they lie down and then cannot get back up.

The first live but afflicted elk transported from the area southwest of Rawlins where 280 have lost leg muscle strength and died or been euthanized, died at the Wyoming State Veterinary Laboratory Friday morning. Two more either died or were euthanized by Monday, Cook said.

Veterinarians had treated four elk for dehydration, plus administered B vitamins, vitamin E, selenium and anti-inflammatory drugs trying to gain insights into the malady that has affected the Sierra Madre herd. One captured cow remains alive and is eating and drinking, but she remains unable to stand, Cook said.

In the arduous process to identify the source of malady, Wyoming State Vet Lab personnel have now ruled out calcium deficiency, chronic wasting disease, bacterial and common viral infections, tick paralysis, and meningeal and carotid artery worm as causes. Mercury poisoning, selenium toxicity, many of the common plant toxins, some insecticides, a variety of metals and salt, nitrate and sulfate poisoning have also been eliminated.

Cook said the analysis of necropsies conducted last week continues and that no definitive reason for the elk illness has been identified.

The Game and Fish is surveying a 50-square-mile area for sick elk and also taking extensive plant samples for analysis. The discovery of dying elk was initially reported to the department on Feb. 8 when a coyote hunter found two elk approximately 15 miles from Rawlins that were alive, but unable to move.