My greyhound has sudden excessive bruising on her outer hind, inner back legs and stomach. I took her to an emergency vet. They suspected clotting and or liver issues as possible causes. All blood work came back normal. An ultrasound of her belly near the bruising was normal. So, the cause is unknown. Vasculitis is a possibility, but the culprit (bacteria, bug bite, other allergy) is a complete mystery. She is 9 years old and has been very healthy the 7 years she has spent with me other than bad teeth. She is on an antibiotic in case and also something for Fibrin. No one I speak to has ever had a dog with this problem. I am scared that there is some unknown underlying condition but am hoping its a strange allergic reaction. She is happy, eats, drinks and behaves normally. Any input would be appreciated. We moved into a newly built condo 5 weeks ago, so she was stressed.