Awww, he sounds so cute!!!
How old is Toby?
I'm sure you're gonna get some great suggestions, but the first thing that comes to mind is to feed them an All Life Stages food - that way they can all be eating the same food. My five range in age from 13.5 years to 7.5 months and they all eat the same food. I know you may have different circumstances with your seniors but it's a thought. Good luck!!
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He is your friend, your partner, your defender, your dog. You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion. -- Author Unknown