I really would like to avoid unnecessary vet visits though, as my mom is very conservative with money spent on our animals, especially since she’s convinced they’re the ones who end up killing our pets (I had two guinea pigs previously who were fell ill, one spontaneously, another possibly from old age. They both passed soon after seemingly getting better and then a vet visit)

After checking some more I’ve found more of these lumps, almost like lymph nodes? throughout his underside. They are small and movable. j

They are small, kind of hard, and movable. Kind of like the lymph nodes, I think they’re called, that one can feel in their jaw area (with your head down). I’m hoping these lumps are similar to the ones we humans have, and that they’re only a concern if they enlarge