My 9 yr old Chi Pom has bright red patches on her belly.?

They don't seem to bother her...she is still eating and drinking water and doing her normal things. She has arthritis in her hips, but other than that she is healthy. I will take her to the vet if it becomes worse or she shows signs of pain, I'm still paying off her dental surgery, so money is tight. Does anyone have any ideas or suggestions on what this could be and what if there is a home remedy. Thank you.