My miniature horse has taken a liking to the pampas grass. I was told that horses usually won't eat something that is not good for them. Before I brought her home, I literally vaccumed the entire back yard. I could not find pampas grass or weeping bamboo on any of the websites of toxic plants for horses. She seems to love eating both of them. However, since she has been eating the pampas grass, she has developed a bit of a dry cough. I am not sure if it is because of the grass or the wet cold weather we have been having. She eats plenty of hay and gets grain twice a day. She still seems very active, but lays down three to four times per day. Is this all normal?