My mini mare did this last year, she made us think she was prego and even devoloped udders. I called the vet and she said possibly too much lush grass, she does have a 2 acre pasture with her Appy buddy. Last year we really thought she was prego because she was staying with a stallion but we sold the stallion this year for this problem. I didn't want to breed Missy anymore. I did 2 years ago when she was old but not ancient but now she is 21 and I don't want to breed her. She is otherwise healthy and very happy and playful, even more so now that the stallion is gone. But she is devoloping an udder again with one side being slightly larger than the other. She does express clear, sticky fluids when squeezed and she doesn't seem to be in any pain at all. Could it be the grass again?
There doesn't seem to be alot of grass out there because the Appy ate most of it. I also took her out of the pasture to a differant section that I have closed off and all that is in that part is thier round bale and water trough with little to no grass, the only grass being along the fenceline and she can reach through and snatch it but that's not enough for her to have this effect. She has been seperated for 2 days now and it's still not going down, it even got bigger! Her nipples are swollen and filled out where they were flat and squishy and obviously unused but these aren't. They are full nipples now. Anyone heard of this?