I had been using NB Duck & Sweet Potato for over a year with great success. In August my Irish Setter stopped eating entirely - took her to the Vet where she continued not to eat for 3 days. We ended up feed ing her hand to mouth with eggs and cottage cheese until her stomach returned to normal. We thought she ingested something or contracted a virus. We started her back on NB Duck & Sweet Potato again and the symptoms reappeared once more. Then I checked this blog and realized that it was the NB food. The new mix is crapola and anyone that loves their dog should stay away from it. There is a comment above that says we should have checked the bag and then to introduce the food slowly. Well I am sorry to say to that person that when you trust a manufacturer and there is not any indication warning to the consumer that the formula has been substituted with junk we feed it to our dogs out of trust of the manufacturer. Other companies put notes inside of their bags to the consumer that the formula has changed. PLEASEDON"T USE THIS FOOD and I would recommend not trusting any of the Natural Balance mixes because if they change Duck & Sweet Potato without notifying the consumer what is to say that they won't change the other formulas to 'save production costs, decrease the size and increase the cost'. One more thing - answering Jak above - I am referring to the substitution of duck meal with duck protein - furthermore duck protein could be composed of duck bills, dick feet and duck feathers.