Mushroom powder for dogs has gone from a niche curiosity to a shelf staple in about three years. Walk through any pet wellness range now and you will find tubs of it, usually with an impressive list of Latin names on the back and a price that suggests something valuable inside. Some of those tubs contain concentrated mushroom extract. Others contain, for the most part, ground-up grain. That is not a figure of speech, and it is not a fringe problem. It is the single biggest quality gap in the…
