Hello everyone, So tonight we noticed an internal lump on my male cats side. His left side in front of his back leg. Its pretty large, about the size of a ping pong ball, and im confident it wasnt there this morning. Hes acting normal (eating, drinking, bathroom) but he will meow or grumble when he lays down or if you touch his side. Ive looked for any kind of cuts or scratches but havent found any. Its internal and grew rapidly, I cant figure out what it is. If it doesnt look better in the morning we will go to the vet, but im wondering if anyone has experienced this before?