Pig not growing, acting strange?

[Silvershine]

I got a new very young sow several weeks ago, and she's been acting very strange lately. She doesn't seem to grow very much and she's very skinny. Whenever I pick up her house to pick her up, she has all her fur fluffed out. At first I thought it was a URI, but there are some other very weird symptoms. I noticed a bare, flaky patch of skin underneath both of her front legs, but I didn't see any eggs or things moving. She doesn't seem to find them itchy, but when I touched them, she started to jerk her head and twitch. Right now, she's sitting on my lap and eating some of her favorite veggies, like usual, but she doesn't seem to poop very much and when she does the poops are very small. More recently, her breathing has become seemingly a bit irregular (almost like panting), and she has started to twitch and jerk her head occasionally when I am not touching the bare spots. My parents are convinced that she has some incurable genetic problem and they don't think its worth it to take her to the vet. I can't figure out what it might be. I've tried to get a picture of the bare spots, but she's young, uncooperative, and likes to bite, so it was impossible. Does anybody know what this is and if (and how) it can be treated so I can convince my parents to take her to a vet?
Other notes:
She lives with a sow several weeks older than her and quite a bit bigger. I have them in a 2x4 C&C cage lined with fleece. Our house isn't cold or hot and stays at a pretty steady temperature. I have not had to bathe them. They get a lot of human interaction.

[bpatters]

Most likely mites. They're very painful, and can cause twitching, jerking and even seizures if left untreated. But they're in an unusual place for mites, which are usually on the back, so it might be worth a vet visit. And if it isn't mites, it's probably a fungus. If it's that widespread, she needs a vet visit for that, also.

Don't bathe her, just in case it is mites. That sends the mites into a frenzy, and will just make things worse.

Sitting with her fur puffed out is a sign of pain.

Is that enough reasons to go to the vet?

[Silvershine]

Yes, thank you! I'll tell them that it's probably mites.