I think that nutrition and the health and life expectancy of your dog is very important.
You said that the food is pricey and that your dogs are "losing interest in it."
There are a ton of great dog foods, but unfortunately, they are all pricey.
The cheap dog foods are just that...cheap.
I currently spend $35 for a 40lbs bag of Canidae. The other "good foods" are all similarly priced.
Kirkland, as well as Pedigree are about $17 for a 40lbs bag.
This should be sounding alarms in our heads.
I was like you, but probably the expense and lack of education about proper dog foods, and I had my previous rottie on Pedigree. He died of cancer this year.
My current dog, Murphy, is on Canidae, after I read all the information about good versus cheap dog food.
I'm hooked and so is Murphy. BTW if he ever loses interest in Canidae, there are more good dog foods out there.
If you need more convincing, read this:
Kirkland
Good luck,
Jeff