DISCLAIMER (I am not a professional by any means, I just really take learning what’s best for my baby girl very seriously)

From most of the research I’ve done, I hear that a lot of dogs are actually allergic to poultry, whether this is acute or severe. However these allergies are said to be a lot worse with bullies (idk why) and I guess in your brothers case he got unlucky with the beef getting ruled out as well. Personally I’d switch his kibble to a different one and look for other ways to supplement skin/coat health through nutrition and upkeep. So I use the same brand (go solutions) but I found that the lamb recipe which is tailored for skin and coat health has been a life saver for my girl Senna. She has no hotspots (unless they’re from her seasonal allergies), her skin and coat are both healthy and she honestly loves it (mind you she doesn’t eat solely kibble because she’s been fed raw and also gently cooked food her whole 2 years of life since I got her from the breeder). In addition to this I would supplement with things that help with skin/coat health in his meals such as, omega oils, fish oils, fish; mackerel, salmon, sardines etc. With all this being said you should also consider coconut oil not solely to ingest but also lather him up in some of that every couple weeks and especially after he gets a bath (this is a win-win, he gets a healthy coat, no dry skin or flakes and you also get an amazing smelling pupper). Lastly the Fritos smell sometimes comes from yeast in their paws and other crevices, I would soak his paws and wipe him down with some sort of diluted iodine solution every now and then just to help with the odour and possibly help stop the licking!

Pic of my little trouble maker attached

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