Using formulas like the one Karen D suggested is very helpful.
You just need to find out what is required for your dog’s specific needs like breed, age/life stage, size, etc
I mix & match my dogs’ foods all the time. And because I have a large breed puppy I have to be very careful about making sure I stay within certain guidelines most importantly calcium & phosphorus, protein, fat.
Because dog food companies typically only put minimum amts in guaranteed analysis I find myself having to contact the companies for their maximum levels.
So you may have to do a little leg work.
When I have the percentages I need I subtract the lower amounts from the higher amounts of the different foods to be sure I’m within the percentages.
