The question should be posed to a veterinarian.

Check out the bad grass list at www.meanseeds.com. I didn't see mexican feather grass listed as dangerous.

Mexican Feather grass (also called Mexican Needle and Thread grass) is terrible for dogs. My neighbors have it, and my little dog inhaled the seeds from it while sniffing around. It nearly killed him. The seeds are barbed, and attached to threads that look like fuzz at the top of the plant. The seeds are so tiny you can barely see them, hence the name Needle and Thread Grass. About $10,000 in vet bills later my doggy is doing okay, but it was a terrible ordeal. It required anesthesia, a magnifying scope, and irrigation of his nasal canals to remove those tiny seeds. This happened about six years ago, and it turns out the grass is invasive, and growing in all my neighbors yards now. Do not let your dogs near it.

I've been bringing in the house 1 gallon or 4" size Stipa for my Indoor cats, for about 15 years but change them often. They love it and helps them go to the restroom, or at least makes their tummy feel better. I always cut buds off before bringing in because of the Barbed seed would be terrible if they got in there nose or throat.

. I agree with Barbi