UPDATE: Must have been something else. Vet gave an oral medicine and everything was back to normal in 2 days. I still feed him vegan food 6 days a week.
A few days ago, I decided to feed my dog vegetables (& some fruits) more often than animal sources like meat, eggs, milk, etc. (He is a 4-year old golden retriever.)
This is what I fed him for a few days: [Whole rice, soybeans, red lentils, sweet potatoes, carrots, tomato, beans, cabbage, spinach, coriander] in the morning and [1/2 apple, banana, 1/4 pomegranate, 1/4 beetroot, oatmeal (with water)] in the evening.
The 1st day on which I fed him the diet went fine. I checked his stools in the evening as a precautionary measure and It seemed fine, I think I saw some undigested soybeans in there, otherwise it was fine, but he sh*t a ton.
I checked his stools in the morning on the second day, and I could still see more soybeans (which I fed the previous morning). I fed him the same diet on the 2nd day as well and checked his stools in the evening. Same story.
On the 3rd day, early in the morning, he vomited what looked like yellowish foam; not a lot, more like 3-4 tablespoons. And from the stools it was clear that he's unable to digest soybeans.
He vomited on the 4th day (early morning like before) as well. Bad stools and vomiting got me worried. So I had the soy and lentils ground and cooked instead of cooking whole. This following evening, his stools are fine and it's no longer a ton. Then he slept as usual and all of a sudden woke up only to vomit some white foam/liquid (could be oats, could be bad stuff happening inside, I don't know).
The same happened on the 5th day. Today he vomited (yellow again) while we were out for the morning walk.
What could be causing this? Could it be because of indigestion (soybeans)?
He's hopping and running around as usual, and I couldn't find indigestion causing yellow foamy vomiting. As of now I've removed soybeans and lentils from his food.
Like I initially thought, my dog is doing great since removing soy and lentils from his diet. So, it's most probably due to indigestion caused by soybeans. I'll add back lentils soon; so this is what I plan to feed him now (5 days a week):
Morning: whole rice/ground quinoa, red lentils, sweet potatoes, carrots, green beans, cabbage, spinach, olive/sunflower oil, coriander/turmeric
Evening: 1/2 apple, banana, 1/4 pomegranate, 1/4 beetroot, oatmeal (with water), honey
Answers to your questions
Before you ask: Feeding him veggies and fruits only isn't very healthy. Give him meat; dogs thrive on it!
I feed him meat, eggs and milk 2 days a week. The rest of the days he gets cooked veggies, and in small amounts, raw fruits, and some grains (whole rice, oats, quinoa)—to provide all the nutrients he needs to have a perfectly healthy body.
As for formulating my dog's diet, we all have our understanding. Just to state what I think——I don't believe that diet is rocket science; except that you should know what you are feeding is nutritious and not harmful in any manner. Then if you vary the diet enough, the dog would be healthy and fine. Meat, poultry, eggs, and milk aren't as nutritious as they once were, and can even be less nutritious or outright harmful in the long-term (due to steroids or bad diet given to source animals, among other reasons). There's no one right way. And I am not arguing. I am sure you all have your opinion.
I'll of course be monitoring my dog's health closely. :)
I'm also concerned about other elements of the diet, raw egg can lead to skin and coat issues as well as running a salmonella risk.
I should have been more clear earlier. None of the ingredients in my dog's diet, except fruits, are served uncooked. Hopefully explained well in the question now.
[...] Nevertheless, I'm not convinced that this diet is healthy.
[...] What's the source of this diet?
I've made a list of the most essential nutrients for dogs, and their sources. Then I made sure that all bases are covered in the diet I feed my dog. The 'diet' on the whole is healthy. If you have more questions, as to whether a dog can be fed mostly-vegan diet at all, you may want to google 'vegan food for dogs'. There IS some credible information.
READ: Homemade dog food: Essential nutrients & their sources
Also, I have cross-checked the ingredients of some of the top pet-food brands.
Do you give the dog the core of the apple to eat? Apple pips contain cyanide, not dangerous in small doeses but if he's having them regularly...
No. The core is removed. I have done my research. :)