Hi everyone,
I was browsing the web and came across an article from the Alaskan Division of Wildlife Conservation regarding packgoats potentially harming Dall sheep populations. I felt the article was a bit bias, but it does make a viable arguement concerning transmission of diseases. I'm sure (although they don't mention this part) the sheep could transmit diseases to packgoats, as well, that goats have no immunity to. I have attached the link. Sorry if you have seen it before, It looks to be recent. I found it quite interesting and potentially harmful to the packgoat "reputation".
http://www.wildlifenews.alaska.gov/index.cfm?adfg=wildlife_news.view_article&articles_id=410&issue_id=69