Lump My guinea pig has a lump on her back?

[C.S.Chia]

My guinea pig is approx. three years old, she's never had a problem before this week.
I had to take my two guinea pigs to Florida with me this year, and when I took them out after lunch I noticed she had a bald spot on her mid-back. She pulled the fur out herself, and has never done this before (she's ridden to the beach before). I chalked it up to stress and boredom didn't really worry about it. But today I was petting her and noticed a small lump on her back, though it's not anywhere near the bald spot. It's seems to be sitting just underneath the skin, and it's just to the left of her back. I also noticed she's pulled a bit more fur out, but again, not anywhere near the lump. It could just be a sebacious cyst, but the addition of her fur loss is concerning.

 

[bpatters]

Is the fur loss in a V pattern? If so, it could be mites.

If the lump is soft and squishy, it could be a lipoma (fatty tumor, benign). Sebaceous cysts are usually a little firmer. You may be able to get some of the cyst material out if you squeeze it gently, but be sure it's GENTLY. If nothing comes out, don't keep fooling with it. More dangerous tumors are usually (but not always) firmly attached. Lumps from infections may be painful to the pig if you move them.

It certainly doesn't sound like an emergency, unless it starts growing quickly. And if it doesn't grow at all, I'd just watch it and wait. But if it is growing, a vet visit is in order at some point.

 

[Soecara]

Just thought I would mention it the lump could also be an abscess, they are quite hard and can be moved with the skin but have no opening and will not produce anything if squeezed (other possibilities were mentioned by bpatters). I would consider any lump over the size of 2cm vet visit worthy, but if it is smaller than that just wait and observe.

The bald patches could be from excessive grooming which could be caused by dry skin, lice, mites, skin irritation or she could be self barbering out of boredom (the last one is unlikely).