My little dog whom is half chihuahua and miniature pincher is eleven years old and has a swollen area near her ovaries any suggestions from those that have experience or knowledge of veterinary care?

She has been always like a sausage like body and is often mistaken for being overweight but essentially she is not, She still has her menstrual cycle and moves around just fine. But at the onset of getting up from laying around she has a slight difficulty getting going.