roborovski hamster not eating

Question
Hello, about two weeks ago I bought 2 roborovski hamsters (both boys) and had them in the same cage (I thought it would be ok since they were in the same cage at the pet store).  They were fine for the first week and then I noticed that they started to fight more, but I though they were just playing. A woke up one morning and the one that always gets picked on had an area of dried blood about 1.5cm in circumfrence over his back and bottom.  I took the other one out and put them in seperate cages, which is where they have been for about a week now.  The injured one is doing much better, he is healing, eatting better, and is much calmer, but the other one (the aggressor) isn't eatting hardly anything now since they've been separated and I'm worried about him.  Do hamsters get separation anxiey? And if so what do I do?  I'm afriad if I put them back together again that he'll start trying to hurt the other one again.
Any advice would be appreciated.
Thank you.

Answer
Hello Jodie,

Try giving him a slice of cucumber, then look for nibbles the next day, If nothing, then contact a vet.
~The reason they may be fighting is that the pet shop may have got the sex wrong, this is a very easy mistake to make. (I have seven Roborovskis, the shop told me they were all girls- but there were actually four boys, so I had some unexpected pups!)