Heat after spaying

Question
Hi, I had my labrador spayed right at 6 months for the hormone issues later in life. Six months later she started bleeding and was swollen and wouldn't lift her tail. I took her to the vet and they said it was a diet issue and that I needed to put her on a special diet because there were probably crystals forming in her urine and that it was too Basic. I said she was in heat and acted like it and there were dogs hanging around the house. They said it was impossible for her to show signs if she was spaid. I waited a week and she was still in pain and mopey and I went back and Insisted that there was a problem and they needed to test her to see if there were hormones in her system. They charged me $80 to test her and blammo, she was in heat. It was too late for that cycle so they waited 6 months for her to go back in heat. When she did (same behaviour)they re-spayed her (opening her up 37 staples worth) and found a remnant of an ovary about the size of a small lime. They said she would be fine and sent me off. Now its been 6 months or more and today she started moving with some obvious discomfort and has the tail between the legs and such. She gets snappy if I try and lift her tail and is swollen and licking alot. She keeps backing up to me and she was humping a pile of clothes which she never does. The vet says that there is no way she could be in heat again and no way the symptoms are related to heat since she has been spayed. They want to do testing on her and change her diet Blah Blah... I just want to know since I really think its hormonal and it should only last a week or so what should I do. I can wait and if it goes away and she acts like this in 6 months (she never acts mopey)should I go to another vet and have them do tests for the hormones and put her through it again? I hate to think of putting her through that trauma again. I am sure that they removed most if not all of her reproductive organs so is it not harmful to her? Is there anything I can give her to ease her discomfort while she is in the cycle? Very Frustrating trying to do the right thing. Thanks for any help you can give. I have looked and not seen anything about this particular subject. Any questions please feel free to ask. Thanks.

Answer
FIND ANOTHER VETERINARIAN ASAP!!!!!!!!!!!  If you live in the United States, you have a veterinary malpractice case at least; at best, you should approach the state licensing authority and report this veterinarian for MALPRACTICE and NEGLIGENCE.  IF you are near a teaching facility (veterinary college), within reasonable driving distance (even four hours each way), GO THERE.

Ask the NEW veterinarian for an abdominal ultrasound.  You may have to take the dog to another facility for this (if you are unable to go to a veterinary college) but it's WELL WORTH it.  Your dog may have retained uterine tissue or have been born with some rare biological complication (multiple ovaries, etc.), this is not something I can determine (and it would be quite rare, but anything is possible.)  An ultrasound will allow the veterinarian to "see" what's going on in her abdomen and if she has ACTUALLY been spayed to begin with.  Have a full blood chemistry done, as well.  The "tail between the legs" is extremely unusual and not part of the normal heat cycle of a bitch; that's a clear indication that something very odd is occurring. PLEASE REPOST WITH RESULTS.