Interesting ... I didn't know higher protein caused gas. I just knew that some brands make some dogs gassier than others. So I looked it up, which I do a lot. One thing I found interesting here
Gas in Dogs: Causes, Solutions and When You Should Worry - Paw Nation is that eating fast can cause it, and dogs with a smooshed-in nose can be more likely to have excessive gas. Both come from gulping air when they eat. You may want to try slowing her down, since you said she eats fast. They suggested smaller, more frequent meals and putting an object in the food bowl, both things you can do with horses when this is a problem. They didn't mention protein as causing gas but did say certain kinds of fiber do. You might try probiotics or prebiotics to help digestion. Also, they said this can happen if you didn't switch from one food to another gradually enough. Since you just switched, maybe that's the cause.
Also, as long as Lexi is getting a nutritional diet, I think she'll build muscle with lots of exercise. She probably needs to run a lot. Can you let her loose to explore the woods, or would she stray or get in trouble with neighbors or chasing deer? I wonder if you could teach her to longe, like you do with a horse. I bet you could. If you can teach it to a horse, a dog could certainly do it. What you do is get a long leash and some sort of long stick to help direct the dog. Or at least this is how you do it with a horse. Then you train the dog to go in a circle around you at the end of the leash while you stand in the middle of the circle. The stick can help prod the animal along if you wave it behind or slow the animal if you wave it in front. Start the animal going slowly in the circle till you're sure she's under control, then up the pace a bit. Teach her voice commands for the different gaits, walk, trot, and canter, which are pretty much like a horse's gaits. Teach her whoa, which means to halt. When you want her to go faster, from a walk to a trot, let's say, lift your voice at the end, and when you want her to go slower, use the same command, from a canter to a trot, let's say, by making your voice go lower in pitch at the end, a more calming sound. That's it in a nutshell. I don't know how this translates from horses to dogs, but I really think you could do it to get her to exercise without you having to run along with her on the leash or ride a bike, which someone in our neighborhood does with his dog on a leash. I've always marveled when he goes by at how well-trained that dog is, jogging alongside him and never pulling on the leash when it sees another dog, etc. Good luck getting the gas under control. That can get really annoying really fast.
