How to Change Your Dog's Food Brand Quickly.

Changes to your dog’s diet should be made gradually. In fact,  taking five to seven days to mix increasing amounts of the new brand of dog food in with decreasing amounts of the old brand reduces the chances that your dog will develop an upset stomach or refuse to eat. But what do you do when you have to switch your dog's food quickly due to a food recall or other circumstances, like a diet-related illness?

To minimize the risk that your dog will have a bad reaction to the rapid diet change, there are some important steps you must take.

Find a Similar Dog Food Formula - Pick a new dog food that closely matches the previously used variety. For example, if your dog was eating a lamb and rice product that was recalled, purchase another company’s lamb and rice formulation. Read the ingredient list. If you can match up the first few ingredients, the foods will be fairly similar. Also, review the guaranteed analysis on both labels. Avoid big changes in the percentages of protein, fat, and fiber, whenever possible.

Offer Small Meals Gradually - Once you get the new dog food home, start by offering your dog a small meal. If he or she eats it and doesn’t develop any tummy troubles as a result,   offer another small meal a few hours later. Gradually increase the size and decrease the frequency of your offerings until you are back to your normal schedule in a day or two. If your dog doesn’t dig in to the new food, pick it up and don’t offer anything (including treats) for eight hours or so. It is okay to let your pet get a little hungry, so long as you continue to offer the new food every 6–8 hours and then pick it up if it is not eaten. Continue this pattern for 48 hours. If you cannot get your dog to eat the new food within this timeframe, consult your veterinarian and try another formulation — but avoid frequent changes in flavor as this can promote finicky eating habits.

Go Easily Digestible - If your dog has an especially sensitive stomach and you are forced into making a rapid diet change, consider switching to an easily digestible formula first and then gradually mix in small amounts of the new, long-term food a few days later. Probiotic supplements can also reduce the chance that your dog will develop diarrhea when its diet suddenly changes.

Consult Your Veterinarian - If you can't find a new dog food your dog likes or, if despite all your precautions, the change in diet resulted in vomiting, diarrhea, or other signs of gastrointestinal distress, talk to your veterinarian. (Adopted From http://www.petmd.com)