Like @Atemas I’m very rigid with what I feed my dogs. Probably neurotically so. 
I have been ever since Murphy got very bad with colitis which was nearly 20 years ago now. He was put on a sensitivity diet and probiotics and I decided if he was on a special diet I should cut out the extras like sausages, left overs etc. He didn’t have a bout of colitis again. Since then my dogs have only had their food. I use kibble as treats with the occasional special treat as a jackpot reward. Some might think it’s mean or excessive but I know what a difference it made restricting Murphy’s diet and I’d rather not feed my dogs something that could trigger colitis. Murphy first got colitis after eating roast beef ! Something you wouldn’t think would upset a dog. I’m not saying you shouldn’t give Hugo lots of lovely treats but maybe restrict his diet more for a while so his digestive system can settle and mature. It’s just a thought.
I have been ever since Murphy got very bad with colitis which was nearly 20 years ago now. He was put on a sensitivity diet and probiotics and I decided if he was on a special diet I should cut out the extras like sausages, left overs etc. He didn’t have a bout of colitis again. Since then my dogs have only had their food. I use kibble as treats with the occasional special treat as a jackpot reward. Some might think it’s mean or excessive but I know what a difference it made restricting Murphy’s diet and I’d rather not feed my dogs something that could trigger colitis. Murphy first got colitis after eating roast beef ! Something you wouldn’t think would upset a dog. I’m not saying you shouldn’t give Hugo lots of lovely treats but maybe restrict his diet more for a while so his digestive system can settle and mature. It’s just a thought.
I would call in to work but we are so incredibly short staffed that I feel terrible calling in last minute. He’s acting happy and bright still. I hope he hasn’t developed an allergy to the food he’s been good on for a couple months now 
I removed his bed and put in towels. I gave him probiotic and pumpkin with his breakfast. I’ve never cooked scrambled eggs for dogs before, I’ll try that after work for him. Currently he is running around playing with Gizmo, throwing his toys about, running around with them. So definitely feeling himself… which is how he was with the food allergy. Only thing I can think of is maybe his training treats don’t suit him anymore, he had maybe five yesterday, they are tiny little low calorie training treats. But I hadn’t given him any of those since initially getting sick 5 days ago now, but reintroducing them yesterday even though very low quantity amount to what he usually gets… maybe triggered it to come back.
maybe he had too much pumpkin yesterday.. too much fibre maybe.