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Breeding Horses/Could mare be pregnant ?


Hi sandy ! I'm worried about my 12 year old mare. She's put on a lot of weight recently it seems to all be around her belly. She's out at pasture at the moment but it dosnt seem rich enough to cause the weight gain. I checked her earlier and noticed she has a small bag in front of her teats and is making a watery white milk. She had a colt two years ago. She hasn't been covered by a stallion or been around any other horses but her son in the last year. They've been together all winter and summer . He was gelded last year. I havnt seen any signs of her being in season. Could she be pregnant by her own son? Could the vet have messed up his castration? If she is pregnant will it cause any problems that the fool is born from incest? Or could this just be a phantom pregnancy?

Hi Kate,

I guess it would depend on when the colt was gelded.  How late in the year?  If he was gelded later in the summer, I'd say he definitely could have bred his dam before he was gelded.  Was he gelded prior to May-July?  If not, there is a good possibility he bred her.
The resulting foal should be fine.  The only thing my vet has ever told me regarding in-breeding, is that if there are any "flaws" within the bloodlines, they are more apt to show up in a foal from in-breeding.

I have personally never seen a mare have a phantom pregnancy.  Now, there are certain illnesses that can cause a mare's udder to swell and for them to have "milk."  But before I would consider any illness, I would have her palpated to see if she is in foal.  You could also check for foal movement as well.  

As for the vet messing up the colt's castration, sometimes they are "proud cut," meaning they have not removed everything that should have been but usually that will only make the colt continue to act "studdish."  Unless he had a retained testicle that the vet did not remove, he probably could not have impregnated a mare.

So... I guess there are a lot of factors to consider here.  When was the colt gelded?  Did he have a retained testicle?  Depending on the answers to those questions, it's a very good possibility your mare is pregnant!

Good luck,

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Sandy Sargent


Breeding issues of both the mare and stallion (live cover), stallion handling, pregnancy of the mare, signs of impending foaling, foaling complications (dystocia), post-partum care of the mare and foal.


Breeding, raising, training and showing of Appaloosas and American Miniature horses for 16 years. Barn/breeding manager of a large Appaloosa race farm for 6 years.

Member in good standing with: ApHC (Appaloosa Horse Club) AMHA (American Miniature Horse Association) AMHR ( American Miniature Horse Registry) FHANA ( Friesian Horse Associaton of North America)

Veterinary assistant for 4 years. I have attended numerous educational seminars on equine reproduction.
Currently employed as a Humane Law Enforcement officer.

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