Spayed but in heat

Hello Vets I have a cute Basset Hound/Terrier cross puppy. She is 11 months old. At 6 months I had her spayed as per the vet’s recommendation. The spay did not go as most spays usual. She said her uterus looked like she had at least 1 c- section from the amount of lesions she saw. But I knew she had never been pregnant. As she proceeded she located the first ovary and removed it. When searching for the second ovary, she ran into difficulties. She did find what looked like a large ovary near the fallopian tube and removed it. It had quite a large blood supply to it. Upon looking at it, she questioned whether it was indeed an ovary or an underdeveloped kidney. After stitching Sandy up, she did an ultrasound but due to blood clots, could not find anything. She sent the uterus and unidentified organ to pathology. I am attaching those results. It was a kidney. I was told she may go into heat. Fast forward to today. We have noticed the odd blood drop on the floor the past few days. Could she be in heat? The vet also said, she may not have removed all the uterus. Do I have to worry about pregnancy if she is in heat? I’ve never had to deal with this before. Please help me. Lastly, my pup was saved from a hoarding situation of 125 dogs. The thought is that she is the result of inbreeding. She was rescued at a young age and I adopted her at 4 months.

Hello- and what a fascinating case!  I realise that no-one wants their pet to be a fascinating case however, because this makes the outcome much less predictable than, for example, something that vets see every week.  I think it's normally safe to say, that if a female dog had only one womb (which most do), and if that womb has been removed, then a pregnancy is extremely unlikely.   However, ectopic pregnancies (pregnancies outside the womb) do happen, extremely rarely.  I've never heard of one making it to term, but it can be an unpleasant complication.   If an animal comes into season, then they clearly do have some ovarian tissue left somewhere.  This can be diffuse (spread out) and not always possible to find surgically.  However, it can result in the female being hastled by male dogs.  It may therefore be better not to keep them in close proximity, depending on the circumstances.