Has your dog with the “sensitive tummy” been diagnosed by a veterinarian? Has he had an annual exam that included lab work (the best diagnostic tool) to rule out medical issues?
I hope you will consult with a veterinary health care professional before proceeding. If my post offends you, don’t read it, maybe someone else will benefit from it.
BTW: There is no cheap way to do raw that is safe.
Some science based veterinary medicine here: http://skeptvet.com/Blog/?s=raw+food
And: https://www.mspca.org/angell_services/choosing-the-right-diet-for-your-pet/
excerpt below:
Raw diets are another popular option on the market today. Studies have shown that 20-35% of raw poultry and 80% of raw food dog diets tested contained Salmonella. This poses a health risk for your pet, but also for humans. This is especially true for children or immunocompromised adults, whether exposed to the raw food directly, or the feces of the pet eating the raw food. Additionally, there is increased risk of other bacterial infections and parasitic diseases when feeding raw diets. And the bottom line is there is no reason to believe raw food is healthier than cooked food.
The numerous dietary choices for your pet can be daunting but if you pick an AAFCO approved food made by a manufacturer with a long track record, odds are good that you will find a suitable food for your pet. Most of the large pet food companies employ full time veterinary nutritionists and have very high quality control standards. That is not to say that a small company cannot produce nutritious and high quality food, but you should check out their website if it’s a company that is not familiar to you. Take the time to research, and ask your veterinarian if you have specific questions or concerns.
Please understand that this article is meant to provide basic dietary guidelines for healthy pets. If your pet has specific health issues, then your veterinarian may make specific food recommendations, which may include special prescription diets.
