russian dwarf hamsters

Question
hi sheila,
i've had my russian dwarf hamsters for two weeks. I was told they were both male but im worried one may be pregnant? they have both started fighting recently but one (which i think may actually be female?) is more aggressive than the other one and is spending alot of time in the house, almost as if nesting? it also looks bigger since ive had them.if i am wrong and they are both male, is the fighting normal behaviour and what do i do about it?
many thanks
amy

Answer
Hi Amy

thanks for your question.

It is quite common for hamsters to be wrongly sexed, so you may well have a male and female.  

What is the fighting like? How often does it happen? Is it aggressive?  Dwarf hamsters can be kept in pairs or groups, however, if they start fighting then  I am afraid that they need separating.  Once separated, it is very hard if not impossible to reintroduce them therefore it is worth making sure that this is aggressive fighting rather than a minor squabble.  If they draw blood, or one keeps being picked on and bullied, then this is a sign to separate. with a pair, often one will be dominant and it is case of the other one accepting this - if they don't then there will be fighting. if one is pregnant then she may well become more aggressive and territorial.  

You may have two females, in which case if there is a litter often they are fine with helping out with the other babies, but as they are already fighting, then this could get a lot worse with any babies ending up getting hurt in the process.

Regarding the possibility that they are different sexes - if so, and if the female is pregnant, then the thing you should know that if she produces a litter and the male is still in with her, they will mate again that day and she may well have a second litter.

The gestation period for a dwarf is 18-21 days so you will know for sure fairly soon if she is pregnant.  

Have you been able to examine them to double check their sexes?  If not it would be worth doing this but you'll need someone to help you to hold them steady.

In case one of them is pregnant, then don't overfeed right now - just give the standard dry hamster mix.  If a litter appears then you can increase her food allowance by giving baby food, nuts, seeds, bread, raw porridge oats, also some raw vegetables (avoid lettuce as it can cause diarrhoea).  

If you do find yourself with a litter then I would advise that you notify the pet shop where you got her.  If there are females in the litter, then providing there is no fighting they can remain with mum, however, any boys must be separated out at 4 weeks otherwise they can mate with their sisters.  Any males can live together. The pet shop would probably take these back from you, or sometimes they provide a spare cage.  You also need to decide what to do with the other hamster - whether to separate now, or wait. It might be worth discussing this with the pet shop to see if they will take one of them back if necessary.

It is a shame when two hamsters fight as it is a nice idea to keep them together, however, unfortunately sometimes this doesn't work and it is kinder for them to live alone, rather than in pairs in fear of a fight.

I hope this helps you.

Regards
Sheila