Friday morning when I went down to the barn to feed the horses, I noticed that something was wrong with Luna: first she was really quiet, second she did NOT attack her food, and last she kept stretching. Those where all signs that she was not feeling well, and probably having colics. For those who don't know, colic can be really a serious condition for a horse, and you could actually have to put it down. With the help of the vet and Luna - she was really good and co-operating - we got the problem solved and by lunch time she was well enough to go back to eat hay with her friends! Big scare for me, but I am glad everything went well at the end!
