I noticed that my cat seems to have a lump/growth on the lower left side of her stomach. She doesn’t seem to be bothered by it. She seems to eat, run, jump, play, urinate and defecate like a healthy cat.
I suspect you mean there’s a lump on the abdomen (her “belly”) rather than her stomach (the organ located inside her abdomen). I’m glad that she doesn’t seem to be bothered by it, but it still needs to be evaluated by your veterinarian. I cannot tell from your description if this lump is contained within the skin, or if it involves the tissues just beneath the skin. Either way, a vet should examine it. Your vet may want to aspirate the mass — insert a needle into it, suck back some of the cells from the mass into the hub of the needle, and then spray them onto a microscope slide. The vet mails the slide to a laboratory and a cytologist evaluates it to determine if it is benign, or if the lump is dangerous and needs to be removed. Most skin masses are benign, but better to play it on the safe side and have it looked at.