We went on vacation in September and had a friend to take care of our horses while we were gone.  We have a 2 year old colt that we had not gelded at the time and a 4 year old mare.  They are stalled at night and turned out in seperate turnouts during the day, or they were suppose to be.  We think that our friend might have turned them out together.  They are half brother and sister (same sire, differnet dams).  I have googled inbreeding and found that it is more common than I had ever dreamed.  Please help me here.  Do I call out the vet and ask him to abort the fetus if she in indeed pregnant?  There are articles on the internet where people have intentionally inbred 3/4 siblings (same sire and dams were sisters).  Any advise? 

If you want and can support the foal, it shouldn't be a problem. If you are worried about supporting the foal after it gets here you should call the vet.  I would also call the vet to get the colt gelded. When leaving a stallion in care of others you never know what might happen. I personally would not take the risk. JMHO

 First, get the vet out and see if the mare is preggers.  You might not have anything to worry about!

Yes, intentional inbreeding happens all the time.  Go to http://www.pedigreequery.com and look at the inbreeding on many of the TB's - scary!  Just because it's done routinely, doesn't make it right and that problems won't happen.

Once the vet is out, you might also get their opinion.  I would vote for a "pinch".  Other than the inbreeding issue to consider, do you have the room/finances/knowledge to raise a foal?  Something else to consider.  

Fingers crossed for a non-pregancy!

There really shouldn't be any problems from this breeding if indeed the mare has been bred.  If the sire and dams of your pair weren't related then there really wouldn't be the same worries if they too were closely related.  Then too, you have to remember that each of your pair didn't inherit the exact same set of genes from their common sire. 

As far as I can see, the only reason to have the vet out to end the possible pregnancy, is if you aren't set up for having a foal so late in the year.  The foal may need a blanket if you are in an area where it gets cold before it can shed out and grow a good winter coat. 

But keep in mind, she may not have been bred at all.  As the days get shorter, mares stop cycling for the year or she may not have been in season while you were gone.  At least talk to your vet and find out when would be the best time for him to come out and do what ever checking and testing is needed to finding out if she is or isn't in foal, so that if she is you'll be prepaired.

Good luck.

Spotted Pony

I agree with the other posters.  Inbreeding shouldn't (hopefully) be too much of a problem.  The real issue (if she is bred-you should have a pregnancy check done) is if you are set up, and have the time and money for raising a foal.  Let us know if you get her checked!

Ha!! Now I know why my horse is such a dork.  His folks have the same dad too!  hahaha   Not really, he is just fine.