Dog food is available generally in two categories. It can either be dry or canned. Both the commercial brands are good for dogs as they generally contain all the nutrition requirements for the dog e.g., proteins, minerals and carbohydrates. Dry dog food is not bad for the dog in any way and does not harm the kidneys. In fact some people believe they are good for the dog's teeth as they prevent tartar build up.
Having said this one should also know that the food should be appropriate for the age of the dog. This is because older dogs should not be given a high protein diet. Their capability for digesting the same goes down with age and may damage the kidneys in some cases. Moreover if the owner, at some point of time, wishes to change the brand of dog food, he should make the change in a gradual manner instead of changing it abruptly.
Having said this one should also know that the food should be appropriate for the age of the dog. This is because older dogs should not be given a high protein diet. Their capability for digesting the same goes down with age and may damage the kidneys in some cases. Moreover if the owner, at some point of time, wishes to change the brand of dog food, he should make the change in a gradual manner instead of changing it abruptly.