Our un-spayed almost 15 y/o dog was in
heat during late Sept-early October, but still has an extremely swollen vulva three months later. Her normal cycle lasts 2 - 3 weeks, occurring approximately 1x per 9 -12 months since age 10 months. She has never been pregnant. She is behaving normally except for increased territorial marking and licking her vulva, both consistent with her usual heat cycle behavior. Concerned about possible pyometra or UTI, I took her to the vet in late Nov.