No Sand No Cough

At first it was Momokuai coughing, then it was AnAn. I have a grim suspicion that the cause is that "hamster bathing sand" which I put out for them. Mimi is the only one who's not coughing and that's because she avoids it altogether. Two days after I removed the sand, I noticed that they coughed less often. That item will be deleted from my shopping list.