“Pink slime” results from grinding together connective tissue and beef scraps normally used to make dog food or for rendering (that would be fat to make lard). The grindings are then treated with ammonia hydroxide, which kills pathogens such as E coli and salmonella. The term pink slime was first coined by microbiologist Gerald Zirnstein in 2002.
It is estimated that up to 70% of the nation’s grocery stores’ ground beef contains pink slime.
Follow the link to see if your local store mixes the slime with the "good meat". It looks like you're safe at a Super Target, Whole Foods, Publix and others. Beware of some of the places. Check it out for yourself. This probably explains the difference in pricing. Personally, I don't really want that slime. If I wanted it, I guess we could purchase a can of dog food cheaper.