The ultrasound is only as good as the person reading it, so it is typically inconclusive in determining if there is actually a shunt. It will show the size of the liver and if there are stones in the bladder b/c the types of stones/crystals associated with liver disease do NOT show up on x-rays.
The Protein C would be a good next step and is affordable. You can find info on that in the liver shunt and mvd group.
Be careful with chicken because as I mentioned meat protein produces high amounts of ammonia which a compromised liver cannot filter and therefore will cause neurological symptoms like the shaking.
Typically a dog with symptoms needs to eat between 2g and 2.5 grams of protein per kg of body weight per day, but considering that she's a puppy, she needs a little bit more. She should eat around 2.7 to 4 grams of protein per day at her weight...
Nutrition facts, calories in food, labels, nutritional information and analysis – NutritionData.com can show you how much protein is in the different foods.
It's also important that you feed frequent and small meals. 4-6 meals per day is optimal. This helps increase her protein amount tolerance and also keeps her glucose levels stable. It's important that you don't overload your furbaby on protein at each meal..
Just one egg white contains 3.5 grams of protein, so that means that she should only eat one egg white split up into 4 meals throughout the day along with a bunch of veggies like the ones you are feeding.
Vegetable, dairy, and egg white proteins are the best for liver compromised dogs.