I did a little Googling for past few days. There are ways that my dog could have gotten a bald patch. He could have chafed on something. Caught a parasite, or possibly a worm. Or it could be a reaction to something. Or he could have nibble on something. Or it could be the dog food.
I checked his stool before it froze. It looked firm. The dog hasn’t suffered any frost bite.
To be on the safe side. I would stick with one brand of dog food. I am not going to risk switching to another kibble. He never had a problem with Benefel, Pedigree and Apo dog food. Those kibble never gave him diarrhoea. He seemed to enjoy Blue Buffalo dog food and Actr1um dog food. So I am stuck with Actr1um dog food. It will be wait and see game.
I swapped his collar for another. His not so old one, had some stretched out look to it.
If you’re wondering, I never give him any seasoned broth. It’s plain broth for him, no salt, pepper or any spices.