Egyptian Uromastyx

Question
Hey there! I had a quick question about my Egyptian Uromastyx (Ms. Cooper).  Well, to start things off, I received her from a friend of a friend last year and I believe that she is almost 5 years old now.  Anyway, they had her in a 55 gallon tank that was loaded with fake plants and didn't have any lights for her.  When I went to pick her up I thought she was almost dead.  She didn't move much and was hissing a lot.  I removed all but one of the fake plants, gave her crushed walnut substrate, gave her a hide and rocks to bask on and immediately gave her proper lighting the heat bulb and the other one that helps them digest properly (uvb, i believe).  after all of this she perked right up after a day or two and was loving her new life as well as allowing me to touch her and pick her up.  I occasionally mix in some tortoise food, iguana vitamin pellets, and dust her food with some calcium dust. One side of her tank gets around 95-110 degrees Fahrenheit while the other side is about 75-85 during the day with a humidity 10-30% during the day and at night it cools down to about 65-75 degrees.  On nights that I know it's going to be very cold I turn on her heat pad which warms up one side of the tank. It's been a year since I have had her and for the past 2-3 weeks she has slowed down on her eating, if eating at all, i have only observed her eating 3 peas last week and two pieces of dandelion greens this week.  She is still very active although i did see that she was sleeping outside of her hide the other night which was a first.  She seems to be a bit thinner and the coloring on the side of her body and face seems to be getting duller and whiter.  Could this be of old age? Brumating? Heat burn? I'm really concerned about her eating and losing wight, she looks rather dehydrated.  What do you think it could be and is there anything you recommend on doing to try and get her to eat? or is that normal? Is there something I'm doing wrong?  Please let me know as soon as conveniently possible.  Thanks!

Answer
Hello Kait,

Which UVB light do you use, is it s tube bulb or a compact/coil light?
How often do you dust her food with the calcium dust?
What type of basking light do you use?  
What type of thermometer do you have, a digital probe, a temp gun or a stick on type?  The basking temperatures could actually be a little higher, to a range of 110-125 & with a cooler end of around 78-82 or so.  
Do you have any pictures of her?
The life span can be up to 20 years, or possibly longer so I don't think it is her end of life phase.  
Has she ever laid infertile eggs before?
If she is losing weight, she could have parasites, or it could be the start or metabolic bone disease also.  
It could be a slight slow down for the winter, but she shouldn't be losing weight or acting ill.  
I would try to get a fecal done on her to make sure she doesn't have parasites or worms.
If she appears dehydrated, I suggest getting some pedialyte & diluting it to give to her in a syringe or dropper to get extra fluids into her.
When was the last time that she shed?

Let me know how she is doing.
Tracie