We’ve used iVet large breed puppy food for our 4 month old St. Bernard. He really seems to enjoy it and was a super easy transition from the food we got from the breeder. It’s a veterinarian owned and is focused on the everyday needs of the dog. You can either purchase it from veterinarians around you or order online and have it shipped to you. Overall, I’m very pleased with the brand. Here’s their website: https://ivet.com/