If he is dragging his butt he most likely needs his anal sacs expressed. The carpet may have given him the rash that you are seeing. You should take him to the vet and see if this is what it is before switching food again as it may not have anything to do with the food. They have a pouch on each side of the rectum that fills up and sometimes they can express them themselves by scooting around on the floor or in the grass. It stinks really really bad so if he is able to express any you will certainly know it. Most people prefer to have their vet express them for them. I will find a link for you with some more detailed info. http://www.animalclinic.com/analglnd.htm http://www.thedachshundnetwork.com/analsacs.htm If you found this answer helpful please remember to accept it.
__________________
If my answer was helpful please click the green accept button My answer should not take the place of a Vet's diagnosis when needed. Positive feedback is most welcome and a bonus-though not required-is greatly appreciated no matter how small.
