I've recently noticed a few hogs on a ranch that I hunt being very sick. They are quite literally skin and bones and move much slower then the rest of there pack. Any idea what this may be from?

Malnutrition?

Sows sometimes get pretty skinny when they're nursing piglets and food is hard to come by.

Whereabouts are you located, and what's the food supply been like lately?

There's an article here — http://articles.extension.org/pages/63662/feral-hog-diseases-and-health-risks
that lists some of the more common swine diseases and symptoms/effects, but I'm not familiar with anything corresponding to a wasting type disease.

There is definitely enough food. From what I can tell, it is definitely a sickness.

Could be genetic, perhaps ulcers in stomach or digestive system.

I had one like that mixed in with our normal hogs that we called skeletor it was so dang emaciated. not even sure how it was up and moving. The general consensus I got is that it was probably an overload of internal parasites. I was going to put it down but it disappeared on its own...

Yup, that's exactly what they look like. After they are shot, no other animals will touch them.