My Mare’s uterus just won’t clear up!!

I found your website while looking for information on my mare's serious case of pyrometria. I haven't been able to find any information on this equine problem on the web. Please, I hope you can help give me some answers for my mare.I found your website while looking for information on my mare's serious case of pyrometria. I haven't been able to find any information on this equine problem on the web. Please, I hope you can help give me some answers for my mare.

Story originally posted by: Michael Lowder, DVM, MS

Hi Dr. Lowder,

I found your website while looking for information on my mare’s serious case of pyrometria. I haven’t been able to find any information on this equine problem on the web. Please, I hope you can help give me some answers for my mare.

I have a beloved 13 year old reg. QH mare that appears to be maiden. I have no prior history on this mare and I have owned her for only 1 1/2 years. She is an otherwise very healthy mare and has only colic’d prior to finding a tumor on her ovary. I wanted to breed her since she is such a nice horse with excellent breeding. During the pre-breeding exam, it was discovered that she had a soccer-ball size granulosa tumor on one ovary. I immediately had the surgery performed on her to remove the tumor. The surgeon said she should be ready to breed in no time, no expected complications. She did have a minor episode of colic right after the surgery but we caught it in time and the vet said it was most likely related to the surgery.

She came into a healthy heat in two weeks and when my vet checked her, although the follicle was small, the heat seemed okay. He performed a biopsy and culture at that time. Both tests came back stating a low grade uterine infection and the lab graded her a 2B mare. My vet immediately recommended uterine lavage with antibiotics during the next heat. So she was given Regumate to cycle her back into heat and the flushings began (x4). Then again with the Regumate and on to the next heat, this time I asked that she be biopsied again before the flushings. The biopsy came back with a uterine infection, although the findings had much improved on the lab report, she still was a grade 2B mare according to the lab. My vet had now flushed her a total of 8 times with antibiotics! He wanted to continue on flushing her again and again over repeated heat cycles until she was deemed clean, but I was running out of breeding time with the stallion’s book and I had waited a year to get her bred to him. So he said go ahead and get some semen in her because she will most likely not get much better at her age anyway. He also stated that if the stud was a potent high producer, her chances were greatly improved. He was, so we went for it. He had a real high sperm count and a great breeding history on AI mares. (My mare had developed nice large soft follicles during these heats. So he agreed that she could go and be bred. My opinion is that sometimes you need to leave things alone and see if they will heal up. The repeated uterine invasions for the flushings and the sedations to my mare really worried me so I wanted to let Mother Nature take it’s course.

So I took her to the stud. She was cycled into heat with Regumate, developed a real nice 44 soft follicle and their vet said to inseminate her right on schedule. (They don’t do live cover) She was only inseminated once per heat, to minimize any more invasion into her uterus than necessary, and their vet swore they got her on the exact day that she was to ovulate. I was told that mares should be inseminated 3 times per heat for the best results?!?!? This went on for THREE months-one AI per heat, with Regumate inbetween to cycle her as fst as they safely could. One time when they went to do the ultrasound and check her for pregnancy, the vet said she had already ovulated AGAIN! How could that be??? Their vet performed uterine lavage after the AI’s and ovulation had occurred. They gave her daily Regumate to supposedly help it "stick" if the egg was fertilized. Their vet could see no reason why she wasn’t getting in foal.

After 3 months and several thousand dollars in fees, I called it quits. She came home to be checked for the third and final time with my vet. One week later, my vet did the ultrasound and said my mare had a uterus full of fluid, no foal. It was horrible. She put the tube in to flush her and before she did anything, one half of a bucket of pus came pouring out of my mare!! Even more after she was flushed! The vet said she had really really bad pyrometria and she probably would have had a serious if not fatal bout of colic within 24 hours and gone down, she was that sick. No outward symptoms at all! The vet put her on 30 days of Tucoprim, flushed her for 4 days with antibiotics, and also administered hormones, Oxytocin, Progesterone to get her cervix to relax to help her expel from her uterus. The infection also caused a pretty good case of laminitis in her. She has just finished all of her meds including Isoxephrine, Banamine, Bute, ProBios, and the Tucoprim. Now I wait each day to see if she will get sick again. The vet will be called in about a month to check her uterus. I just wanted her left alone for a little while to heal before she was sedated and re-invaded again.

Now after all of this, I know that she has a very tight cervix, even when in heat. I know that for whatever reason my vet can’t seem to get a clear culture or biopsy from her and I wonder why the stud farm didn’t note the tight cervix or fluid build up in her uterus upon their vet’s ultrasounds?

Do you think everything possible has been done to clear her uterus up? Do you think I should even consider trying to breed this mare next season? Is there anything else I should try to get her uterus cleaned up once and for all? I get such conflicting stories from breeders, stud owners and friends, that I don’t know if I can get a foal from her or not, or if I should even try, knowing the risk to her health. I want a foal really really bad from her before she gets too old but I cannot see trying if it will make her sick or me financially bankrupt! I would really appreciate your opinion on this. Please do not use my full name on your website, I do not want to offend my vet if they read your column! Thanks.

PS: Do you think live cover would have made any difference at all? Some say yes, some say the added semen would have made things worse.

Thank you,
Sincerely, Carla


First let me say I appreciate where you are at now. I used to work a lot of broodmare farms in Alabama before coming to Georgia. Your history says a lot about the care you have for this horse. However, I will be as straight with you as I can. In my opinion, for what it is worth (not much by some) is that the breeding of this mare is over.

I have never seen or heard of someone clearing up a mare with pyometra. A mare with a IIB would only have a 10-50% expected foaling rate (a large number will get pregnant but would not carry the foal to term). This mare would have had qualifying inflammatory changes and fibrotic tissue in the uterus prior to all of this (before she was sent off).

Now, I don’t want to be the one with the bad news and I would suggest you have your vet refer you to a theriogenologist for a complete breeding soundness exam. There is a very small chance that this mare can be bred but as you have found out it will take money and time.

Dr. Lowder