dehydrated rat?

Question
I have 2 male rats approaching approx 2 years old. I adopted them from my college where I'm studying animal science so they where in a controlled environment all their lives (with minimally invasive procedures done on them, mostly handling practice).
Recently the past few days, I noticed the smaller of the two, "Boo-Boo", has been getting thinner and his skin has been looser. I can now feel most all his ribs, tho he was pretty trim to begin with. I also pulled at his skin and it mostly stayed out suggesting he was dehydrated. Boo-Boo has also been having more 'red tears' at his nose. They live in our garage for the summer where it's fairly cool and i have a low fan circulating the air for them, still its the hottest they've ever had it so I was thinking he might be overheated?
I will call my general vet tomorrow but i saw this site and thought to get your opinion. What is your 'diagnosis' and/or what do you think would help him? Thanks for your help!
Margot

Answer
Hi Margot

Rats cannot handle heat at all, esp elderly rats. Temps in the upper 70s and around 80 to 81 is about the highest they should be exposed to. They can dehydrate and have heat stroke very very fast.

I would push fluids big time, using any means, via a dropper or even putting a little dish down of flavored water with some koolaid.
I would also go out and buy childrens pedilyte. This is great for dehydration and replaces lost electrolytes. Rats tend to love the taste too.  Offer them watermelon too. This also helps them keep fluids going.
You can also make "mini air conditioners" for their cage. What you can do is fill up plastic soda bottles or plastic milk jugs with water and freeze.  Once frozen, put in the cage and the frozen water will let off cold mist and will cool the cage down considerably. Even those plastic ice blocks used for coolers can be used as long as they are not the gel filled ones they can bite through.

Is there a way you can move them to an air conditioned area?  I am going to assume they are in a cage and not in a glass tank but if they are in a glass tank they need moved to a cage for better circulation.

Hope this helps as far as beating the heat goes.

However, since only one rat is acting this way, it may not be from the heat, although I would still take the steps above to keep the hydrated and cool no matter what of course. Anyhow since this seems like only Boo Boo is feeling unwell, it may be something more than the heat.
He may be ill from some underlying problem. Weight loss and dehydration is also a sign of kidney problems or heart disease too so I would keep an eye out for other signs such as rapid breathing, tires easily, changes in habits when urinating, etc...