Swollen Hind Feltlocks but NO Injury

[Sassy_Music_06]

Could someone tell me what could be wrong with my 2yr old Quarter Horse mare, Sassy? She has heat, and slightly swollen hind feltlocks, but there seems to be no aparent injury even after she has been hosed down.

Her hooves have been trimmed at one time to a point and have yet to show signs of even growing. I am unsure as to if this could be the problem or not.
Further more, the place where I board is extremlly muddy and I have asked for her to be placed in a stall until the problem has been dealt with, with no such luck.

Any advice?

 

[Sassy_Music_06]

When I was lunging her, she nicked her back hind on the right hand side but it was treated once I noticed and cleaned it out. The place that I board at is very, VERY muddy. But her legs are cleaned as often as I can get out there.

Any ideas??

P.S. I have considered Mudfever but have had limited money to get the vet out which will be done this month coming.