One of my biggest challenges in the first year of being a Vizsla owner was Kaylee's "issues" with putting on and maintaining weight. There wasn't a single, magical solution. It took a number of small changes.
One of these changes was to use a food with a high calorie to volume ratio. I used a home made food called Magic Meatballs (a.k.a. Fat Balls, a.k.a. Satin Balls.) It contains more then twice the calories per volume as kibble.
There probably as many different ways to make Magic Meatballs as there are people that make them. I started my recipe with Pam William's recipe. I then clarified the directions with information gathered by searching the web for other recipes, things like a 12 ounce jar of wheat germ vs. jar of wheat germ. I then added additional changes to get the recipe in line with Sue's recipe (Kaylee's breeder and co-owner.) Finally I added additional changes based on my experiences, like using a mixer to crush the egg shells and mix the ingredients before adding the hamburger.
You can find my current recipe by clicking the link below. There's a couple additional changes I'm looking at making. One is a suggestion from Holly Hatfield who adds a 12 ounce can of pumpkin. Pumpkin works as a natural anti-diarrhea for dogs.