Christina Eyth, of Fairfield Township, Adams County, had found the animal after following snowy footprints outside her door thinking they would lead her to a neighbor's loose dog last weekend.
The animal went missing sometime between Wednesday night and Thursday morning, according to the shelter.
“There had been no evidence of escape attempts," Wildlife Works-Mount Pleasant wrote in part in a Facebook post.
"We had him for about a week, during which time he ate nutritious food and received treatment for his mange and secondary infections. We can only guess he was starting to feel somewhat better and decided it was time to go."
The animal's treatment was originally estimated to take 2 to 4 weeks, according to a post by the facility.
The experts at the facility are searching for the animal and ask people in the area to keep an eye out. “Check your trail cams. He may turn up around houses again. Call the office immediately if you think you have seen him. DO NOT try to capture him on your own,” the shelter says in the post.
The woman who found the animal is upset about this turn of events. “I am at a loss of words. My heart is broken. I am very devastated. Please pray he is found safe and alive so he can finish his treatment. Please pray he is found or comes back!,” Eyth said in a Facebook post.
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