Just want to reiterate that you really want to be sure exactly what is causing your mare’s behavioral issues before deciding to spay. In many cases, as @JB noted, spayed mares display perpetual estrus. So the procedure might be completely counterproductive for your purposes. The only spayed mares I’ve ever worked with, in fact, were owned by vet schools and were spayed specifically so they would “tease” as if in heat 24/7 and could therefore be used as “jump mares” to collect stallions on any given day.
5 Likes
I’m really curious about this based solely on my knowledge from human and canine fertility. How/why would this occur if ovaries are removed? What would cause the continued estrus if there are no ovaries?
1 Like
The way one vet school therio explained it to me was that the display of estrus behavior in mares is caused not just by estrogen but by lack of progesterone. No ovaries = no corpus luteum to secrete progesterone = estrus behavior.
9 Likes
The two spayed mares I have known were constantly in heat for the rest of their lives. It’s not an uncommon side effect. They make good teasers, are awful for anything else.
4 Likes
This is an interesting thread. One thing I’m not seeing anyone comment on, is longevity of performance career in the spayed mares, in cases where the spay surgery was actually an effective intervention.
I know human and veterinary medicine are often not parallel… but in humans, when you remove ovaries several years/decades before natural menopause, you have a significant increase in early onset of osteoporosis and cardiac issues.
I’d be curious if there are similar implications for equines after undergoing the surgery. I’d also be curious if there are many examples of high performance mares, who were actually spayed relatively young, and how they did in their later years in terms of their joints holding up well for their performance careers. That’s a challenge for plenty of horses, even without an additional risk.
Anyway, just an additional thought. Maybe it’s totally irrelevant because of differences in the role estrogen plays in the equine body vs. the human body… but asking questions about it might be worthwhile. Hormones in both human and veterinary medicine play roles in various tissues throughout the entire body, well beyond their primary reproductive related role.
7 Likes
To address a few things that have come up. Progesterone keeps a mare out of heat, estrogen induces heat. Mares only produce progesterone in their ovaries, so spaying removes the only source of the hormone that keeps mares out of heat. However mares produce estrogen both from their ovaries and the adrenal gland, so there is still a source of the hormone that induces heat after spaying - which was explained to me by my vet as why mares can still show heat symptoms. (Again, I’m not going into this blindly and working with a team of specialists. This is not a typical case). However, the mare will never actually experience a true heat with ovulation again - so if you have a horse that experiences real pain or discomfort from ovulation, or you have a horse that has some abnormality in their ovary that is not yet visible on ultrasound, spaying will be beneficial. My mare definitely experienced the former, and we suspect may also have the latter situation as well.
I cannot say the situation more plainly that this: mare has been evaluated by multiple, very experienced vets (lameness and repro) and it had been determined that for her health and comfort, and for her own safety as well as others, that she should not experience heat (as in a true heat with ovulation). We have not been able to achieve this through less invasive means and therefore are exploring surgery. I understand the procedure does not create a gelding and I have no expectations of that.
For those who shared their own experiences with spayed mares, I appreciate it. For those who shared alternatives or opinions on spaying, I will defer to the DVMs who know and have been treating the horse for such matters.
14 Likes
Noted.
FWIW, I wasn’t trying to advise you on any alternatives or offer an opinion on your mare’s particular situation… which sounds quite challenging. I was only commenting on what MIGHT be a worthwhile question to ask a veterinarian (are there any long term bone or cardiac health and soundness implications for a performance mare if her ovaries are surgically removed).
My apologies for engaging in too much tangential discussion on your post… 
. Good luck with your horse 
4 Likes
This forum is known for our sharing of opinions; solicited or otherwise 
Just take the info you need, ignore the rest. Even if we keep giving it.
12 Likes
Thank you! I appreciate the well wishes.
And @StormyDay - I’ve been posting and perusing this forum for over ten years now, and that is exactly what I’m doing 
2 Likes
My question is this: what is the actual diagnosis?
Being unbearable during a heat cycle doesn’t always mean that being in heat in of itself is the culprit. Often times things that are just borderline tolerable from day to day — like a microinjury or undiagnosed pain elsewhere — are made worse while the mare is cycling.
Until there is a definitive diagnosis I would caution you against pursing spaying. You’ve had a lot of people chime in with real experience with this — but it hasn’t been the answer you want to hear.
8 Likes
Not at all. The experiences, both good and bad, are helpful - although I’ll admit I put more stock in the more firsthand ones and was hoping for more information on experiences with the recovery process.
I guess you’ll just have to take my word for it that after extensive vet work we are confident her being in heat is the culprit (or not, doesn’t so much matter to me ).
2 Likes
Why doesn’t it matter to you?
1 Like
Why doesn’t it matter to me whether someone on an Internet forum believes my horse being in heat is the culprit? I would think that would be a little self-explanatory.
6 Likes
I wish I could find it too, I went looking again after my comment here, and still can’t find it. I’ll keep looking!
1 Like
I don’t think she meant ‘why doesn’t it matter if we take your word for it’ but read your statement wrong and thought you meant it didn’t matter if the diagnosis was right in your mare.
1 Like
There is a mare at my barn who was spayed because of behavioral issues under saddle. They went through her flank and the recovery was pretty quick. I don’t remember what it cost, but my guess is $3000. Sadly, it didn’t change anything.
1 Like
In terms of recovery, my SIL’s mare was done standing via flank incision. Her incision had been closed with internal sutures and tissue glue. She spent a couple days in a stall, then was back to normal turnout (closed herd in a smallish paddock). IIRC, she was able to return to light riding in a couple weeks and was back to full work (casually ridden trail horse) within a month. Always possible that wasn’t the vet-suggested timeline, but it worked for the mare.
Is this a thing? I know a couple horses who do this, and I thought it was just stall boredom.
It apparently was “a thing” for her. Have never seen another mare do what she did (constantly). Tail up, peeing, legs spread apart, bumping hard into the wall with a “dreamy” look on her face. What would you call it LOL? Drove the geldings crazy. A “sex goddess”.
I had a racehorse who had been left a colt, and retired him at the end of his three year old campaign, started jumping him. This mare was his first love, he broke his maiden on her. From then on, it was “coloured women” who caught his eye, solid colour mares he’d walk on by at the shows without picking his head up. Oh, I forgot to say, she was a buckskin appy, big blanket, dark spots, half TB, 16.2 with a big blaze. Showed across the continent in the hunter divisions in her competitive career in the mid 1990s. Not another one like her, ever, in any way.
7 Likes
I had a mare in my care who would throw herself against the walls – especially during feed time. It was always more dramatic when she was in heat.
I considered it a type of food-related stereotypy as she really only did it after PM turn-in or right before AM grain time. I think she had some mild pain associated with cycling, was frustrated she was in a stall, was anxious about graining, and was letting it out.
I put rubber mats up on the walls and it significantly decreased the behavior.
3 Likes
