The THK base mixes are all designed to make a complete meal when an appropriate amount of raw OR cooked meat is added (or even eggs). So you can literally add hamburger to the THK and get away with it because it has added micronutrients to balance it out so that you don't have to keep a spreadsheet to track them.
I feed THK with raw beef. If I can get it, I use ground heart (with or without 10% or less liver and kidney for extra nutrition) because my dog loves raw beef heart. The problem I have is that I have to drive about an hour to find a butcher who will grind up the hearts for me right now. If I can't there, I will just use ground chuck. He's always been a hard keeper and seems to do better with more fat in his diet, so 80/20 meat is okay for him -- with a fat dog, or a dog at risk of pancreatitis, I'd use leaner meat. If there's a sale on any other beef (stew meat, etc.) I wouldn't hesitate, at least if the store would grind it or chop it for me...if you don't mind doing that work at home, you will have a lot more options!
I talked to THK about bone, and they said for an adult, the calcium they added to Preference/Grain Free is sufficient but there's no harm in also feeding some recreational bone if you choose to, or even using a frozen product like Primal Grinds (80% heart/10% organ/10% ground bone, with no added vitamin packs) as your meat in the base mix. You don't have to -- but you won't hurt the dog if you do. For adults, the nutrition is a range that's flexible enough to give you wiggle room.
Primal Grinds runs about $4-ish per pound. Since it has no added vitamins, it actually works pretty well with a base mix. It's not labeled as complete without the added vitamin pack, but those are already in the base mix. It's hormone/antibiotic-free beef too, so it's a little better than most grocery store meat. Keeping a few chubs in the freezer will give you options.
I agree with adding fish oil. You can do this in capsule form or squirt some into the mix that you prepare. If you buy it bottled though, be sure to store it in the fridge. Interestingly, the THK employee that I talked to by phone also added fish oil for her own dogs.
Another thing to consider for a dog with chronic issues is a digestive enzyme added to the base mix. This might be something like Prozyme or an all-in-one supplement like Glandex. I add the enzyme powder at the same time I add the water to soak the HK mix.
Last edited by Magwart; 03-29-2019 at 10:59 AM.