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  Discussion on Persistent estrus, both ovaries atrophied, nymphomania
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Member:
frances

Posted on Saturday, Jul 27, 2013 - 7:22 am:

My mare who is now 26 has been in estrus for about a whole month now as far as I can tell. It is not at all uncommon for her to have very heavy and lengthy heats, but this one is exceptional in length and intensity.

Last Tuesday she also showed up severely lame in the right hind, and had ataxia in the front legs (right fore wavering and crossing in front of or landing on left fore). Very scary, and I would like to ask your opinion on this in another thread DrO. I am assuming, though not sure, that there is no connection between the lameness (at least the ataxia part) and her persistent estrus.

When the vet arrived regarding the lameness issue(s), the mare exhibited unbelievable hormonal behaviour, screeching if anyone approached her or held a hand to her muzzle, or anywhere. I have owned her for 18 years and never seen her behave like this.

We managed to lead her out of her stable, but she was extremely hyper and almost rearing, thus the vet couldn't make an examination, gave her a shot of bute and arranged to return the next day.

Yesterday the vet brought an elderly specialist in mares out of retirement to ultrasound her in case she had a cyst, uterine infection or any other obvious cause for her behaviour. His conclusion was: no cyst, no infection but tiny atrophied ovaries (both). His diagnosis: Unnatural atrophy of both ovaries from unknown cause, leading to nymphomania. He said there was nothing to be done for it, but that it wasn't causing her any discomfort. I assumed that he meant this was a permanent situation, but on leaving he said that this is not a static condition and would change all the time. He finds it an interesting case and wants me to let him know next time she has a normal length estrus so he can come and see her again.

What is your take on this DrO?
Moderator:
DrO

Posted on Saturday, Jul 27, 2013 - 6:39 pm:

Hello LL,
What about the possibility this behavioral change is do to a change in management or circumstances?

Nymphomania and aggression (usually toward other horses) is typically the result of excessive amounts of estrogen-like and testosterone-like hormones or a increased sensitivity in the brain to normal amounts of hormones. Excess amounts of these hormones is also associated with small ovaries. It makes me wonder if there is not a sex hormone secreting tumor either somewhere else in the body or possibly on one of the small ovaries. Typically we think of granulosa cell tumors has enlarging the ovary but there are reports of GCT's on normal appearing ovaries. Possibly you have a very small tumor that is causing the ovaries to shrink.

What were the ovaries sizes and consistency on the US?
DrO
Member:
frances

Posted on Thursday, Aug 1, 2013 - 1:31 am:

No changes in management or circumstances. No aggression towards other horses. In fact when she is in season she is very docile and sleepy. In the winter months or at the times when she is not in season she can be cranky.

I asked the vet (who brought the US man) if he could have missed a tiny tumour, but he was adamant that this man was highly experienced and would not have done so.

I was particularly interested in your comment about increased sensitivity in the brain to hormones, as it's possible that she had West Nile encephalitis (see the reference I made earlier to her incoordination).

I'll start the new thread as I mentioned I would on the other symptoms she showed that day.
Member:
frances

Posted on Sunday, Aug 4, 2013 - 11:53 am:

Your comment about excess amounts of testosterone-like hormones as well as estrogen-like ones is spot on, as I think actually the mare hasn't been in estrus all of the time, but sometimes her urinating has been more like a stallion marking in the same place, rather than a mare squatting to urinate and winking. Today she was squealing like a stallion and fighting to reach another mare whom she has always been attracted to, shall we say. The mare responds, too.
Moderator:
DrO

Posted on Thursday, Aug 8, 2013 - 1:40 pm:

You might consider some of the testing discussed in the article on GCT.
DrO
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