Mare acting like a stallion to a new mare

[hollyhardy32]

I have had my Irish Sport Horse 16.2hh mare for 9 months now and she is the most sweet and calm horse to ride and groom. Perfect hacking out and doesn’t spook easily at all…

…However, one month ago we bought a 3 year old mare Shetland as a companion for her.
Since her arrival, my 16.2hh mare’s behaviour has completely changed, so bad I haven’t even been able to ride her for over a month.
She mounts the Shetland and bites her neck so hard that her coat has come off. The Shetland squirts and winks at my other mare but my mare acts like a stallion towards her.
I had to sedate her to take her away from the Shetland to get her new shoes as now she doesn’t let me put a head collar on her.
When we have tried splitting them up, the mare jumped a 1m+ gate to get to the Shetland and then proceeded to hump her.

Does anyone have any advice as to why she’s acting like this and why it hasn’t subsided after 1 month constantly together?
Really struggling!!!

 

[TheMule]

Sometimes ovarian tumors can cause havoc with the hormones and cause this sort of behavior. I would have her scanned and, if all clear, try her on some regumate

 

[Hepsibah]

Has she been with other mares in the nine months you've had her? With this sort of behaviour in a mare I'd be thinking a hormone disorder. Perhaps speaking to your vet about blood tests might be an idea.

 

[MyBoyChe]

I would want to be absolutely sure the new mare isnt in foal! Ive only seen this happen once before and the unstallion like mare turned out to be in foal!!

 

[hollyhardy32]

Sometimes ovarian tumors can cause havoc with the hormones and cause this sort of behavior. I would have her scanned and, if all clear, try her on some regumate

I’ll have to give the vets a ring tomorrow!!! Would regumate help with this situation?

 

[hollyhardy32]

Has she been with other mares in the nine months you've had her? With this sort of behaviour in a mare I'd be thinking a hormone disorder. Perhaps speaking to your vet about blood tests might be an idea.

Nope, she hasn’t been near another mare but she has hacked out with another gelding dozens of times and she squealed when they first met but that was it.
It’s literally just started the past month!

 

[hollyhardy32]

I would want to be absolutely sure the new mare isnt in foal! Ive only seen this happen once before and the unstallion like mare turned out to be in foal!!

Oh christ!!!
We bought her from a trustworthy Shetland breeder that my boyfriend has knows for 10+ years. He keeps his stallions 1 mile away from his broodmares. I don’t think she could be, but wouldn’t hurt to get her scanned I suppose?

 

[Melandmary]

This happened to me with my mare when I moved yards 4 years ago. She had always had mixed turnout with no issues so it was a shock when she went into the new herd and had a complete personality change. She took a particular fancy to a mare that was almost constantly in season and would mount her. She was unhandlabable, would break out of her stable.... Just absolutely horrid. I couldn't understand it and the new yard owners were quite annoyed with me for it. I had her ovaries scanned, no problems there and then put her on regumate. Then oestress. She did calm down a bit but what helped most was just moving my mare in with a different mare. Problems stopped and my mare went back to her usual old self. In your shoes, I would scan but then try removing the shetland elsewhere. My mare was rearing in my face and was down right scary until we put them in seperate fields

 

[hollyhardy32]

This happened to me with my mare when I moved yards 4 years ago. She had always had mixed turnout with no issues so it was a shock when she went into the new herd and had a complete personality change. She took a particular fancy to a mare that was almost constantly in season and would mount her. She was unhandlabable, would break out of her stable.... Just absolutely horrid. I couldn't understand it and the new yard owners were quite annoyed with me for it. I had her ovaries scanned, no problems there and then put her on regumate. Then oestress. She did calm down a bit but what helped most was just moving my mare in with a different mare. Problems stopped and my mare went back to her usual old self. In your shoes, I would scan but then try removing the shetland elsewhere. My mare was rearing in my face and was down right scary until we put them in seperate fields

This is exactly my issue!!!
It’s like she’s a completely different horse.
The only issue I have is that when we took the Shetland out last time my mare was going bonkers trying to find her abs would jump anything/go through anything to get to her.
My mare just wants to be with the Shetland all the time. I’d have to completely split them up and put them miles away…

 

[coblets]

More probably, ovarian tumours. Less probably, she’s intersex.

Has this behaviour ever happened with other mates or just this Shetland?

 

[Clodagh]

Has your mare previously always lived alone? If so they can get far too attached to company. I’m not sure that explains the mounting but could be a contributor to such severe SA.

 

[hollyhardy32]

More probably, ovarian tumours. Less probably, she’s intersex.

Has this behaviour ever happened with other mates or just this Shetland?

Since I’ve had her she has never been turned out with another horse… we have hacked with a gelding and on the hack there are other mares and geldings in the field which she does kick up a fuss to go over to but with a lot of leg she just walks on and is fine.
I do know the previous owner used to compete with her and was on loan for for some time too so will have been with other horses as well. But I’m her previous home she was the only horse in a field with cows and sheep.

 

[hollyhardy32]

Has your mare previously always lived alone? If so they can get far too attached to company. I’m not sure that explains the mounting but could be a contributor to such severe SA.

I know at her previous owners she lived alone which is why I wanted company for her.
For the past 8 months with me she was in a field with sheep and she loved their company, she would let them sleep in her stable and even share her food.
I was thinking it was just separation anxiety as well but it’s the vicious mounting and completely changed behaviour that is quite frankly scary to watch that makes me think otherwise.

 

[Melandmary]

Hollyhardy mine had always had turnout companions though and yours hasn't. That is either because the previous owners had the same problem with her or just through ignorance that horses need their own kind for companionship... And now that she has it, she doesn't want to lose her new friend. I would definitely get her ovaries scanned to rule out any medical issues and then you can work on the behavioural aspects after. Things I would try are adding another mare to the field so she is never left alone ( 3 is always a better number) and then removing the shetland for short periods at a time then lengthening whilst other mare is still in. If it continues with the shetland but not with the other mare then you may have to rehome the shetland if she has been purely bought for companionship because she will get injured if the mounting continues. Hope you get to the bottom of it soon ?

 

[hollyhardy32]

Hollyhardy mine had always had turnout companions though and yours hasn't. That is either because the previous owners had the same problem with her or just through ignorance that horses need their own kind for companionship... And now that she has it, she doesn't want to lose her new friend. I would definitely get her ovaries scanned to rule out any medical issues and then you can work on the behavioural aspects after. Things I would try are adding another mare to the field so she is never left alone ( 3 is always a better number) and then removing the shetland for short periods at a time then lengthening whilst other mare is still in. If it continues with the shetland but not with the other mare then you may have to rehome the shetland if she has been purely bought for companionship because she will get injured if the mounting continues. Hope you get to the bottom of it soon ?

Thanks for your comment!!! I have booked a blood test on Tuesday so fingers crossed that should show something!
I have also contacted her previous owners to see if they have had any issues with this in the past.
If nothing is shown then I have a number for a equine behaviour specialist so fingers crossed that’s the last resort!!!

 

[Bellaboo18]

Sounds like the poor mare has lived alone for a long time. So it makes sense she will struggle with separation anxiety, she's not going to risk her new found friend leaving her. The stress of that and being poorly socialised will cause trouble.
I'd get her scanned but wouldnt be surprised if her aggression is more stress related.

What a shame she's been alone for so long.

 

[hollyhardy32]

Sounds like the poor mare has lived alone for a long time. So it makes sense she will struggle with separation anxiety, she's not going to risk her new found friend leaving her. The stress of that and being poorly socialised will cause trouble.
I'd get her scanned but wouldnt be surprised if her aggression is more stress related.

What a shame she's been alone for so long.

I’m ringing her previous owners to see if she’s been with others in the past.
She is getting a blood test on Tuesday so hopefully that will show something!

 

[Gingerwitch]

I’m ringing her previous owners to see if she’s been with others in the past.
She is getting a blood test on Tuesday so hopefully that will show something!

So pleased you are working on this, all to often folk post, don't like the answers and poor horse is ignored or returned to a state it was in previously, without anyone really investing in the underlying cause.

 

[milliepops]

my horse who was kept with just cows/sheep and without equine company before i got her is completely antisocial in the field now, she has separation anxiety but beats up anything she is turned out with. i have to keep her in a separate paddock, so long as she has a horse next door she is happy. i think being kept without other horses for any length of time can really screw some of them up socially.

 

[hollyhardy32]

my horse who was kept with just cows/sheep and without equine company before i got her is completely antisocial in the field now, she has separation anxiety but beats up anything she is turned out with. i have to keep her in a separate paddock, so long as she has a horse next door she is happy. i think being kept without other horses for any length of time can really screw some of them up socially.

Could you easily separate your horse from the others without her kicking up a fuss? Does she not attempt to jump over the fence if she’s on the other side? As mine will literally jump over anything to get to the Shetland.
But also when when they’re in the field together they do get on and eat grass right next to each other but then randomly the Shetland will start winking and squirting and my horse will mount her, bite her neck and scream.

 

[milliepops]

mine is very respectful of electric fencing fortunately, and their paddocks are adjoining. I have a "spare" horse on the yard so I am in complete control of her companion, i literally never turn her out or bring in without my other horse, they go everywhere together

she would try and climb out of the stable if left alone. i have a full grill top door for her for those occasions, she gets very distressed but I can keep her safe.

i wasn't saying mine was exactly the same, just illustrating that sometimes they forget how to "horse" when kept alone. it doesn't sound like a match made in heaven if the shetland is flirting either.

 

[hollyhardy32]

Hi guys,

I have spoken to her previous owner and she has assured me that she was with other horses at her house and was fine with them.
We do know her past owner as well so the information she’s given me will be the truth, she has even sent me a picture of my mare with another horse at her house.
She said that she has never acted like a stallion towards another horse either.
Maybe it’s just this Shetland she’s taken a dislike to?