Petsmart, and petco just notorious for ich infested fish. It's just hard to treat ICH in a planted tank. Their fish come from huge fish breeding/grow-out ponds, which arnt the cleanest of places for sure Check the isle where ich meds is, you'll never see it over stocked, always on the cusp of being close to under stocked. Those med sales make them $. Just be careful, and good luck
I'd stay away from all fish offered at the box stores, they're more likely to crash your tank through ich infection than anything else. It's bad enough trying to keep out all the nasty stuff that comes in through trades and SNS purchases.
I will say, that I've never had an otto catch ich; though they can be the vector in to your tank.
Just bought a few more today. Couldn't help myself just watch them sit there in a box store tank while they pray to end up in a good home. So I can part with about 5 in about a week or so after i can guarantee they are healthy for the same price I got them
I picked up a half dozen Otos yesterday. When I got them home I realized one of them was actually a Chinese alge eater! Not the best community tank fish. I may end up rehoming the little (for now) guy.