If I ever find an easy, affordable solution, I am going to share it all over the Internet and even pay for Google Ads to let every dog owner know who searches for dog + prednisone
At least in this case, the answer to dog hunger from steroids is, ironically, to lose weight if the dog is overweight.
Earlier this year, my elderly dog with chronic bronchitis was put on a diet, with apples and veggies as snacks. The weight loss helped with her chronic bronchitis and reduced her need for steroids.
She has now been off steroids completely for about two months. She is on the NSAID Galliprant for her arthritis. (Today, she had her annual lung x-rays, which showed only residual lung inflammation. Her lungs have never looked better compared to the last couple years. She also no longer has a heart murmur.)