guinea pig lump

Question
Hi, last march we brought my son 2 female guinea pigs for his birthday. one has always been bigger than the other. we had them sexed at 6 weeks to check sex,both seemed female. however picked up the bigger one 2 days ago and she has a lump in her belly . quite low on one side. she has been eating a lot and drinking a lot.does this seem like a tumor or do you think we possibly have sexes wrong and she is pregnant. lump seems quite firm but not rounded.

Answer
sorry for taking a long time to reply my email notification had not come.

have a look at her/his parts, a female has a Y shape and a male o-. i would take them to a breeder or local pet shop and ask if you are not sure.

it is possible that it is a tumor, thoughmore likely that they are either overweight, which amusingly does happen to guinea pigs, or else that she is pregnant. sometimes babies do sort of form more on one side, one of my sows seems to only ever carry babies on her left, they all turn out fine though. increased eating and drinking does suggest pregnancy too. overall if she is pregnant she will start to take on a pair shape.

witohut a photo I dont think I can be much more use than that,

sorry again for the late reply.