Symptoms include appetite loss, lethargy, fever, vomiting, diarrhea and dehydration. (itchmo.com)
First, ensure that your veterinarian has examined your dog and declared him healthy and that you've addressed the lesser - known causes of appetite loss mentioned above. (peterdobias.com)
Another common condition that can cause appetite loss is overgrowth of the teeth (see above). (safarivet.com)