I brought my mare in from the paddock and when I went to pick her feet I found she had grown a large lump on the outside of her left fetlock. It wasn't there yesterday when I picked her feet after I rode her. She wasn't lame, hot, etc. What could this be, as of now she is in a private paddock as she is getting over a cough. So that rules out a kick or a bite. Could a bad bug bite cause such a large lump(about 3cm sticking out and 5cm long)? She wasn't lame, but she didn't like it when I touched it. I don't know she has me stumped once again!
Thanks for any advice :)