This past February I had to put my foundation mare down due to colic and copd.....
I kept her blanket, washed it and about 2 weeks later we had a cold spell for North Carolina....I had to purchase 2 new blankets for 2 of my horses.....Everything was fine once all three equine were in their respective stalls....one by one I put them in crossties and proceeded to groom and place the blankets on them.
Here is where the excitement begins....I turned all 3 out into the pasture together and never once have I ever witnessed any vengefull behavior....The youngest mare had mom's blanket on while her sister had a new blanket on....The eldest sister tore after her sister with vengence the likes of which I had never seen on our farm before....she tore the trimming straight from under her tail and bit her causing her to bleed....I managed to get the 3 back in their stalls, lock them in and took care of Holly's wound and blanket.....the blanket on her older sister was taken off and placed upon Holly.....I turned Cori out into the pasture and locked her out of the paddock where her sister and pony were grazing....Cori broke the fence to the paddock causing a nail to shred the new blanket her sister was wearing......again I had to lock all three in their stalls and take the new blanket up to the house for repair.
My question to you is what would cause Cori to act so violently towards her sister....They were both born on our property and have resided with the other horses all their lives and never showed any animosity towards anyone let alone each other.....
Look forward to hearing from you soon. I love the lessons thus far and am looking forward to many more assignments.
MaryJo E. Morse
Horse Behavior and Training