13 month old boxer in heat

Question
My female boxer is in heat and started peeing blood when peeing.. Is that normal? She has been in heat for about a week and a half and this just started a few days ago..

Answer
She will be in heat for 28-30 days, so keep a calendar, as most have 2 heats per year, ranging from 5-6 months apart. If she doesn't, then have her thyroid checked as it can delay heats and stop them, let alone abort puppies and even prevent pregnancy. Just for your information of the heat.

The blood isn't coming from the bladder, like in "peeing blood" but being washed as she pees.

Unless this continues each and every time she pees for any more than 5 more days; call your vet and talk to them. Most vets and their vet assistants, will "diagnose" a slight situation over the phone-- or if they feel it is necessary or abnormal, tell you to come in. And they will either:  1) set an appointment which indicates it is not serious, or, 2) tell you to bring here in now... which indicates it is serious.