I know this can't be good, but when Simba is on the playground he likes to go in his bunker and he loves shredding the grass mats. The area is enclosed mostly, just open on both ends. Well he shreds and shreds and shreds, and today when he came out of the bunker, he let out a little squeak and it looked like smoke coming out of his mouth . I guess with all the dust from the mats, so now I will need to give him something else to shred down there instead of the mats, any suggestions??