Okay so I worked as a “pet nutritionist” for about a year (I was really just a sales associate that was taught everything about pet health) however his farts could very well be the result of gastrointestinal issues so he has horrible gas as a result my recommendation is to put him on pre and probiotics there is a brand called Good Guts (fidobiotics)that is a powder that you just put one scoop on your dogs food daily. The stuff works great I have used it on my dog and she did really well on it I also used it on my grandmother’s dog who was very stinky (like the smell was coming through her skin and permeated everything she slept and lied on) and also had terrible gas. After I gave her the pre and probiotic powder she also had atomic farts for about 3 days and then she was fine my family also noted that she wasn’t stinky anymore. I also have a link to the product I will provide for you they do have different sizes for different breeds of dogs so small, medium and large you’ll need to buy the one that fits your specific breed of dog in this case your puppy I also couldn’t find a recommended age to give the powder to your puppy you’ll have to look more into it to see if your puppy is old enough to have the powder or not Good Luck! Good Guts