A. The differentials are many in this case and it may vary from a diet related gastroenteritis to a more severe infection.
As a first approach I would recommend to starve him for 8-12 hours (give him water if he wants to) and then start feeding him with a bland diet based on boiled chicken and rice in smaller portions every approximately 4 hours. If he does not get any better in the next 24-36 hours I would recommend to take him to your veterinarian for a check up and appropriate treatment as it may need more investigations (as X rays and loos test) or more aggressive treatment (antibiotics and fluid therapy). If you require to discuss this problem further please request a consultation and I will happy to answer all your questions.
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