I brought in a new 3 year old filly to my barn a few days ago. I also have a 6 year old mare I’ve had at the same barn since she was 3. Yesterday, I put the 3yo next to the 6yo in the cross-ties and the 6yo acted extremely interested in the 3yo, however nothing unusual really happened. Today, the 6yo went totally nuts seeing me lead the 3yo past her stall. She whinnied, reared, bucked and acted somewhat stud-ish. She never got over it and was distracted and whinnying while I rode her. Then she obsessed about the 3yo the rest of the day and actually didn’t finish her dinner this evening.
What is it? Jealousy? Hormones? She may be going into heat but I didn’t see her show it. I’ve never seen anything like this. I board at a huge facility with 400+ horses. New horses come in weekly and this mare never takes notice. I also work with another mare that is 8 years old and several geldings and she never had a problem. What’s with the new 3yo? Anyone?