Leopard Gecko feeding problems

Question
QUESTION: My sub-Adult Female Leopard Gecko has recently stopped feeding. she stopped hunting, and did not make any attempt to feed on the 6-8 crickets i feed her every other day. 2 days ago i did manage to feed her a wax-worm in an attempt to fatten her back-up, but she hasn't eaten anything since. she has now reached a dangerously thin level, especially in her tail, and the outline of her backbone can be seen on her back. i have looked in my books and on this website and i think it's intestinal worms, but i cannot be sure. she lives by herself in a 3-foot vivarium with small bark chips as a substrate, which could also be lending to the problem.

Please help me because she is my only pet and i want her to be well again.

ANSWER: Hello Connor,

Are you giving her proper heating?  Do you use an undertank heater along with a basking light for creating a hotter end of around 88-90?  
The bark chips could be posing a problem of impaction.  Have you ever seen her ingest any that you can remember?
I would get a fecal done on her as soon as you can.  It could be worms or parasites.  
Also, change out the substrate right now, & just put some paper towels down to eliminate the possibility of her being impacted.  
Are you measuring the temperatures in the tank, & if so what type of thermometer do you use a stick on type, a digital probe or a temp gun?
I think since she is losing weight to that extent, you need to begin assisted feeding.  Try some chicken or turkey babyfood with a plastic dropper or plastic syringe.  Just drip it onto the end of the nose & hopefully she will lick it off the end of her nose.  
Let me know how she is doing.

Tracie

---------- FOLLOW-UP ----------

QUESTION: Thank-you for all your help Tracie,

We Changed her substrate for Calci-Sand which she seems to enjoy more, because she was digging and exploring. we also changed the layout of her vivarium to give her a change of scenery. a few days after this we tried her with a small feeding of 4 crickets covered in vitamin powder, which she hunted energetically, but when she got a cricket in her mouth she immediatly spat it back out. I then removed the crickets i put in, and replaced them with 4 crickets without vitamin powder, which she hunted and happily ate 2 of. We then checked the powder and found that it was out of date. Could this have been what was causing the problem?

If she doesn't gradually start eating more crickets, would we want to begin assisted feeding?

The temperatures inside her vivarium are 85-90 at the warm end and around 75-80 at the cold end, measured by a stick-on thermometer.

Also, if we do start assisted feeding, how much babyfood is needed to be dripped onto her nose?

Answer
Hello Connor,

Well, I hate to say but calcisand is very dangerous for leopard geckos.  If she ingests it, she could become fatally impacted.  That stuff clumps like cement & it is almost impossible to pass.  I highly suggest a solid substrate for leopard geckos.
Yes, if she does not start eating pretty soon, you will need to start assist feeding her.  I would try 1-2ml's 3 times per week to help her gain some weight back.  
The stick on thermometer is not accurate for basking temperatures, only the ambient temps & humidity.  I would try to get a digital probe or a temp gun for better readings.
She might not like the dustings of the vitamins.  Have you tried just straight calcium powder?  Maybe leave a dish of plain calcium powder in her tank for her to lick when she wants or needs it.

Let me know how she is doing.
Tracie