This is our story. It contains real life examples of the dietary challenges we've faced with our robust red cattle kelpie cross.
It's not intended to take away from the interesting, relevant and important answer provided by @RebeccaRVT. Hygiene is, without question, essential.
Our brown dog was a gift from friends at 8 weeks of age (him not me) and we're still together fifteen and a half years later. He's an awesome dog, but he's not been without complications, especially the last few years.
Three years ago he almost died as a result of post operative effects of major spinal surgery, essentially to save his life, following a vicious dog attack. He didn't eat for ten days following surgery and was forced into a second hospital visit to rehydrate and recover.
His diet after hospital was essentially cooked chicken breast meat - it being literally all he would or could eat without suffering serious digestive problems. To this we slowly introduced cooked vegetables and cooked rice. Eventually his digestion became stable and we began including dry biscuits and other foods. However he lost his ability to digest certain foods such as lamb, pork and pork products.
This stable period ended and during the last twelve months our brown dog has suffered serious digestive issues.
To add to my old mate's complications, he more recently developed incontinence.
To attempt to resolve these issues our vet ran tests at different times over the last twelve months. Each result suggests a dog in good health and in our vet's words "he has the blood and organs of an eight year old animal".
Despite his age he leads an active life. He is vocal, barking to catch our attention and remains interested in everything that happens around him. He still takes long walks and loves meeting with other dogs at the parks where we walk him.
Bouts of constant "jelly poo" diahorrea and the continuing incontinence have presented significant medical and practical challenges.
Having little effective support from our vet - "he's an old dog" - I began my own research and test diets.
For a while we thought we had the problem solved - he was sensitive / allergic to grains.
So we excluded grains from his diet and that appeared to solve the problem. We had a paleo diet dog! (Joke) That is, until the severe bouts of diahorrea returned. (No joke)
Some more research suggested that we may have literally starved our brown dog of the essential fats that cause his canine metabolism to function properly. By cooking all his food we were chemically altering his food and in particular, destroying the naturally occurring fats in meats.
A dog's metabolism relies on naturally occurring fats to trigger proper organ function in his digestive system.
So I hypothesised the following...
Too much acid in the stomach and the pancreas can/will not produce enough bicarbonate and then, most of the enzymes and bile prepared by the liver and pancreas will be ineffective.
Too little acid in the stomach and enzyme production and bile release are not properly triggered.
Perhaps not enough acid was being produced in his stomach.
Our brown dog literally presented symptoms of enzyme deficiency and pancreatitis, however as mentioned above, veterinary tests on his blood, urine and faeces have concluded this is not the case - in fact he presents as a healthy middle aged dog.
We're involved in a continual trial of dietary adjustments.
So after this significant history lesson on a brown dog... what works?
Raw food works. All the time, every time.
No biscuits. Not even grain free biscuits. Maybe small amounts, but by the end of the third day, the return of the jelly poo diahorrea.
In the morning; raw beef mince, raw egg, lightly cooked broccoli, cauliflower and carrots, fresh celery tops, parsley.
In the evening; lightly cooked chicken breast fillet, lightly cooked broccoli, cauliflower and carrots, fresh celery tops.
Hygiene works.
Wash your hands before (and after) handling the dog food. Clean the food bowl. Clean the water bowl. If possible, use fresh meat or alternatively keep all meat frozen until required. If using frozen meat, use a microwave to defrost but not cook the meat. Frozen veges make meal preparation easier too.
Also never starve your dog or place them on "fast" unless it is medically advised and supervised by veterinary professionals. Our dogs rely on us for food and it is unfair to be inconsistent in food supply. We transition changes over periods of at least one week. Patience is required.
Hope our experience might help you work out a solution that is good for your dog.