Help with an underweight gerbil!

Question

I think one of my gerbils is underweight.

He's about five months old, and seems to be a lot thinner than his three month old friend who he lives with. He is eating fine from what I can see, and his teeth look fine, and he has been drinking. There's been no diarrhea or anything like that.

However, I can feel his backbone, he seems more tired, and is lighter when I pick him up, which is easier than it used to be.

What could be wrong?

He seems to sleep a LOT more, eyes half shut, fur all scruffy, though I've seen him grooming.

Answer 1

just give him more food to fattern him up

dont u work in a pet shop so u should no but ohye u dont do u coz u sed that dont u think people in pet shops dint know that much and the site is copied it state that on the homepage and ive got links to the sites that i got he info from and email me y last time u had a question that i answered which was nothin to do with it u gave me a best answer y did u  

Answer 2

          try to buy all different types of food till your gerbil finds one that he really likes and just keep feeding it to him.

          my gerbils favorite food is sunflower seeds they have to be unsalted.  If you cannot find a package unsalted just take the salted ones and put them in water and dry them off the salt will come off.

          you can also feed gerbils human food which they seem to like more such as lettece, grapes cut in 4th's or halfs, small carrot pieces, and corn.  

       you can feed this the gerbil seperate from the other food or mix it in with his normal food.