breeding horses

Question
I have a Haflinger mare that had a foal in Feb,2010. She was in a pasture with a 1 1/2 year old Friesian colt. I thought he was too young to do anything, he was always doing the "I'm a baby thing" I sold him in March and my Haflinger has been exposed to the sire of her last foal and shows no interest but she is getting very fluffy. I did a peepee test on her and it came back positive so my question is can she carry this foal to term, she isn't half way and already huge! Both horses are heavy boned and I have seen ads for Friesian Arabian crosses, not that I would do that, I'm just saying some people claim to have done it so should I be concerned? With her first foal she went through a stage where she got really big then almost looked not pregnant then went fluffy again, is this normal?

Answer
Hi Chris,

I wouldn't be overly concerned if she is in foal by the Friesian.  Even full Friesian foals tend to be quite small at birth, compared to their size full grown.

It has also been found that foals of crossbreeds will not grow bigger than what the mare can deliver.  Granted, she may still have foaling complications, as any mare can, but the foal would not be so large that it couldn't be delivered.

As for your mare looking really large at certain points in her pregnancy and then not so large again, that is normal.  A lot of their look depends on how the foal is positioned at a certain time.

I'm curious about the "peepee" test you performed on your mare.  I have never found, nor heard of a urine test for horses to determine pregnancy.  If there is one, I'd love to know about it!