Lump on neck??

Isabel is just over 3 months now, she will be going to the vet in a week to have her spay and her herniated belly button fixed.
Yesterday, while she was sleeping I felt a weird lump on her neck, just a little to the left, below her mouth. She didn't care if I touched it, and it felt like it moved around. What do you think it is? Should I be worried? Could it be a tumor of some kind? Or maybe it's just a tissue build-up from play fighting with her mom? Any thoughts?

It could be a fatty tumor, or it could be an infection from a bite.... For now, I'd watch it closely & make sure the vet looks at it when she goes in to be spayed!

My Josh just had a lump on his neck and it ended up being an abscess, thank God. My vet, however, tested for leukemia because she couldn't get close enough to him to check it and wanted to rule out the possibility of cancer.

Definitely have the vet take a look at it, though. Josh had to be on antibiotics for 2 weeks and it ruptured in such a peculiar place I had to make a neck tube out of toilet paper rolls so he couldn't scratch it. He couldn't wear a cone because the area was lower than where the edge of the cone would have sat, and it wasn't healing because he kept scratching. grrrrr!

He's back in one piece now.