leopard gecko look sick & losing weight

Question
Hi we have two leopard geckos who look very ill. We bought one about three months ago and we thought it might not be perfectly healthy because it wouldn't eat much and did not move around much. We took it back to the pet store and they said it was fine so we went to a different store and bought a second. The new one acted like it was supposed to for a while but it did nothing to improve the mood or habits of the first. The new one shed twice and was gaining weight. Right now the first one we bought looks very bad, like it is shriveling to nothing and the second is still pretty normal around the midsection but it's tail has shrunk down to nothing and it doesn't run around much anymore. My question is: Is this an illness or are we doing something wrong? We feed them 12 small crickets once a week, keep the tank and water clean, and the temp. is about 80 during the day and 65-70 at night. Do we need a vet or just change something we are doing?

Answer
Hello Adam,

Well, are the housed together?  If so, it is not a good idea to put a sick one in with a healthy one.
Since you bought him from a petstore, he most likely has a parasite or worm problem, since he is losing weight.
You should get a fecal on him, & he will probably need, depending on the fecal results, either Albon or Panacur.
You can start right now by getting some chicken or turkey babyfood & getting some food into him with a plastic dropper or syringe.
At 12 crickets per week, that might not be quite enough food.  How old are they?  
They need a hot side or basking temp on one end at around 88-90 to digest their food.  On the hot end, you can place the moist hide/cave to help with shedding.
What are his stools like?  Runny or smelly?
The cool end should be around 78-82.
What type of thermometer are you using to measure the temps with?  A round stick on analogue thermometer, a digital probe or a temp gun?
I realize it is difficult to find a vet who will see a gecko, but try looking here:
www.herpvetconnection.com

If you cannot find one, I can direct you to get some medication & I will help you dose him.

Tracie