Dogs affected by different food

OldMeg you sound like my sort of person, I spent my life in racing yards and the spoils from the farrier were always the hooves for the yard dogs, fond memories

My dog developed bare patches on his tummy when I changed his dry food to a cheap one. That said he loves Bakers which I have been told is McDonalds for dogs!

Where we lived before....

Mine are partial to horse droppings too Maw and to hoof parings when the farrier is working. It’s meant I have to find an alernativr fertilisers for my roses..

Where we love before Ginger McCain’s string used to pass our house on the way to their gallop on Birkdale Beach. I’d watch for them passing and be ready with my shovel. Some of my best roses were treated to Red Rum’s droppings ?

Getting back to OP yes, different foods certainly affect dogs’ behaviour (and health) . Hope your fur baby (had to put that in to rattle the anti-euphemism brigade) has settled back to his usual placid self?

It happens with cats as well. When DH was in and out of hospital last year Tesco substituted our usual cat food with some coloured biscuity stuff. I can't remember the brand but it wasn't one of the cheap ones.

It made her completely hyper. She didn't know whether she wanted to be in or out and her usual eating pattern was all over the place. It took a while for her to calm down but once she was back to her normal food she was fine.

Our previous lab/retriever cross had terrible problems digesting anything and permanently had the squits, until an older vet told us to start feeding him boiled rice and Chappie. That worked a treat and is still our fall back position with our current lab.

Exactly and those multicoloured mixers and treats are lethal and I think there are a lot of dogs out there that are hypo for no reason due to food

We had a Labrador for 16 years and Pedigree pet food used to have THE most disastrous effect on her digestion.
Straight through her, if you get my drift! She was happiest with the cheapest food which she would supplement with stolen sausages, horse droppings and the contents of our neighbours’ bin bags. ?
Our present dog, Hattie seems to be doing well on fresh raw food which arrives every month frozen. My only problem is finding enough freezer space. If this is not TMI there is less “waste” and it is very pick upable, being firm and well formed. She is not the sort of dog to leave food in her dish for a nanosecond so having it sitting around is not a problem, but finicky eaters (rules out Labradors!) may do better with dried complete food.
And yes, I think food and additives do make a difference to behaviour.
Just think of children and blue Smarties!