When in doubt,take her to the vet.
Yes,it could be vessels but not sure.
My small shih tzu is 4 weeks going on 5 weeks pregnant (she was bred intentionally and all pups have homes already). Her breast has been getting bigger and tonight when looking at her stomach I noticed in some spots it looked blue/purple under the skin kind of like blood vessels. Is something wrong or is this just because of her stomach and breasts getting larger. She does not seem to be in any pain or anything. Is this normal? I can try to get a picture if wanted
Now this morning it looks more like a bruise. I called the vet and she said just to watch it and if it gets worse or she starts acting weird to take her in. I will try to upload the picture. I am new to this so bare with me.
Be sure to also check for a discharge. Good luck.
Take her to the vet ASAP my Shih-tzu just had a litter and she never had that. I would get it checked out. Good Luck!