Androulla, I'm sorry to hear to hear of this with Bobbie. Because you're responsible for him at this time, you'll need to be particularly pro-active and not "watchful wait" any longer. I recommend that you bring Bobbie to his vet - hopefully you have permission to do so - to be thoroughly examined and treated predicated upon the results of his exam. His diarrhea and now anorexia and panting aren't symptoms pathognomonic (specifically indicative) of any one particular disorder. Because he has worsened rather than improved overnight, he should be attended to by his vet at your earliest convenience.
Simple dietary indiscretions - eating something new, inappropriate, spoiled, or a non-food item and more serious disorders such as pancreatitis, hepatitis, and gastroenteritis are important differential diagnoses at this time. Panting can be seen with the pain, anxiety, or both with these disorders. Please respond with further questions or concerns if you wish.
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