guinea pig lump

I have also found a lump on my guinea pig, im not sure if thats its bone but its sticking out above her hip bone near her bum, and i dont think there is another one on the opposite side, im going too look more into it now and see if i can feel anything thats not normal near it.

This is hartening to read - comparing the two sides can be useful when trying to work out if something is normal.    You need to know whether this lumo is in the skin / quite superficial in which case you need to see a vet very soon, or whether it is deeper / possibly internal / may involve bone, in which case we would reccommend having the situation triaged.

(That is, a typical lump will need to be checked out in the near future, but a fracture, wound or protruding organ etc may be a bigger emergency and may need to be seen out of hours, hence the triage).

Obviously there are a few situations which may not be quite so clear cut.  Best of luck and please let us know how you get on.