Val, I just looked up foxtail. OK for just about any animal but dogs. I think it is just the brown parts(after they ripen) that are bad. The seeds have something that causes the skin or any other part inside or outside of a dog to pus and the seeds burrow into the pus canals. The sites say it is very dangerous for dogs but usually not fatal. The fatalities come when the seeds get into the lungs. Try this site:
www.healthyfoodforpets.com/Foxtail-Grass
Good luck and I sure hope Nelly is OK.