My two dogs (a 10 year old pit/lab mix and a 8 year old yellow lab) did not do well with the Wellness Core foods. They have always been on the holistic/all natural or organic foods and have tried most all of them. My dogs had never tried Wellness but my cat has and it's worked well for him. I was really excited about the Wellness Core fish formula for my itchy yellow lab. I bought the chicken Core for the other dog. I fed them a VERY SMALL amount for a week (2 Tbls. of dry and 1 spoonful of the matching canned formula added to their regular meal which consists of homemade and has been that way for the past 5 years.) Both dogs hid in other rooms of the house when finished eating for about 40-60 minutes. When they came to find me, they didn't seem right. (Both dogs were fine before the meal containing Wellness !) As the week went on, they kept hiding immediately after their meals. They grew increasingly tired not wanting to play anymore, no interest in their toys or attention from me. They stopped greeting me at the door when I came home and their usual happy, relaxed faces were looking unusually tired and drawn. By day 3 I noticed they were drinking alot more water than usual, and the smaller dog was getting up in the middle of the night to drink more water---something she has never done. I thought maybe they just needed some time to get used to the new food...although they have tried many new foods before and never had a reaction like this. They became increasingly lethargic, I decided by day 5 to not give them any more Core foods for a day and a half---and they seemed to do a little better but they were still very tired/no energy. I had been so sure this food would be great for them, I had purchased over $40 worth, and decided to give it one last chance before returning it to the store. Within 20 minutes of them eating the meal, they were hiding again. My yellow lab came when called but sat herself on the couch and immediately went to sleep. The other dog never came. I found her lying on her side, head stretched out on the floor and her eyes closed. I thought she had died, as I called her name and talked to her...there was no response. I began to tell her to get up and finally she lifted her head but the look in her eyes said she was very sick. I wrapped her in a blanket and she did seem to feel better in about an hour. I did return the food to the pet store. It took 5 days for the dogs to get their energy back enough to start playing with their toys again and it's now been 7 days and they seem back to being their usual healthy, happy puppy-like selves. They will be seeing their vet to have tests done to make sure there is no permanent damage, the increased water drinking has stopped. How such a small amount of dog food can make 2 dogs that never get sick this sick---I don't know. They both got sick immediately after eating the new food...they both seemed to get better together immediately when the food was stopped. I'm glad I didn't give them a larger amount of the food to eat. The lot codes were 7CDFS1, 7WDZS1, May 31, 2009, July 30, 2009. The food hasn't been out on the market long enough for anyone to know what it's going to do to pet's over a length of time...as with any pet food since FDA regulations are low...feed to your pet at their own risk. My dogs are now on 100% whole food diet with veterinary supervision and doing super. No more expensive, unrecognizable junk out of a bag or can for them!!