Please reply as soon as possible

Question
Hello. I have been very buisy lately and recently i was going to trim my guinea pigs nails and i felt a large oval bump under her skin on her lower belly. I have no idea what it is and im afraid to mess with it. please reply as soon as possible if you have heard of this before

Answer
Yes, I've heard of this before. In fact it's common in sows. Depending on exactly where on the belly you felt it, you are most likely feeling is a mammary tumor. They can grow to significant size and are usually malignant.

As frightening as that sounds I don't mean to panic you. Many sows live a very long time with these tumors. It depends on each unique circumstance. Cysts are fluid filled pockets often cause by infection. They rarely appear on the belly and are usually found on the neck or throat area. Those are very treatable. Mammary tumors are not. So do not try to do anything with this lump.

If it's more on the side of the belly it could also mean an ovarian tumor, common in sows over three years old although they've been known to appear at younger ages. Those can be treated by   a 'piggy hysterectomy' also known as spaying.

If you are able to spend the amount of money it would take to do surgeries to remove mammary tumors then perhaps you can buy some time for her by doing so. Guinea pigs in general don't handle anesthesia as well as other animals do. So that needs to taken into consideration when deciding a course of treatment. Spaying is less complicated than a mastectomy on a guinea pig and has a far greater chance of successful outcome.

I suggest you have her examined by your vet and get his professional opinion. Then you can make the decision as to what should be done. Once you know exactly what you're dealing with you can make a more knowledgeable decision about what to do from there.