Mice are very prone to obesity -- often, they are used for obesity research.
The stock in petshops is also very poorly-bred, and so genetic faults will
show up more readily. This may be expressed in ways like a higher
propensity for tumours or obesity. Often, with a tumour, there will be an
un-evenness to the mouse's outline -- like a 'bulge' in one area more than
in others, on a fat mouse. Sorry, but not much can be done for that. I've
had to euthanize two girls with tumours, because it makes them very unhappy
little critters (understandably). Just keep her comfortable, and help her
out gently when the time comes. Also, people on this NG with far more
experience in diet formulation than me can probably advise you on the best
thing to feed mice for really good health -- but a good diet includes lots
of variety, not just store-bought seed mixes. Maybe something is lacking in
the diet that would make her feel better?
BTW, we have two girls, both from the same litter -- one is the size of a
baby rat (a BIG mouse, and not very thin, either), and the other one is a
little tiny thing. They really are all very individual.
Still -- maybe you'll soon be the proud owner of a bunch of lovely little
babies!
Best of luck to you and the little girl,
Y.
Lucat bene si ergo
Fortibus es inaero
O nobil demis trux
Sum es causen summit dux
-- Anon
dagger <dagger DeleteThis @madrigal.ath.cx.nospam> wrote in message
news:dagger-7922EE.17421810102003@madrigal...
> I bought a new mouse to renew my interest in mice about 4 weeks ago.
> Initially she was a happy vibrant little thing in her new home but she
> has grown larger and larger and has become more dormant just sitting in
> ner nest; she's now too fat to even run on the wheel properly! I've read
> that the gestation period in mice is approx. 21 days, but I am now fast
> approaching having her for four weeks with no sign of a litter. One
> would think she would certianly have given birth to her litter by now if
> she was impregnated at the pet shop.
>
> I purchased a breeding female from the petshop to assist with the litter
> and as a companion about a week after I thought that she was pregnant,
> she is happy as ever.
>
> What is the best way to tell if a mouse is pregnant? Should I take her
> to a vet?
>
> Many thanks,
>
> dagger >> Stay informed about: Is this mouse pregnant or just plain fat and lazy?