Pregnant Mare tried to mount my other (dominant) mare when she came in heat. Why?

Question

I have a 2 1/2 month pregnant Belgian mare who is 12 years old. My other horse is an American Warmblood, 11 years old, who is the dominant mare. On one of her heat cycles my Belgian mare tried to mount her a couple of times. No other stallion like behavior except for this one day. She did not get aggressive in her behavior at all. She is due for her 3 month ultrasound this week. Has anyone else experienced this before or have any input. I am aware that a possible cause is an ovarian tumor, but I have heard other things too. If you can share your experiences I would love to hear them.

Answer 1

Could just be a dominance thing. I have a female dog that "mounts" a less dominant male dog now and then. I would imagine that the same kind of behavior could occur with horses, although I haven't seen that before.

David

http://gentlenaturalhorseman.blogspot.co...

Answer 2

Likely her hormones are out of whack.  This happens often with bred mares (not the mounting thing, just the hormonal thing).  All mares are different and handle their pregnancy different.  

If she is doing it regularly and you are concerned about your other mare suffering injury, I'd seperate them during the week or so your other mare is in heat.

Answer 3

Hate to break it to ya, but pregnant mares don't go in heat...

Answer 4

pregnancy confusion, all those hormones.

i reckon dominance is the cause as well.

but i have to idea sorry. ask the person Doin the ultra sound