There are many reasons why dogs will not eat or drink and have shortness of breath. The more common ones include canine distemper, intestinal diseases, etc. You need to go to the hospital for examination and testing to confirm the cause. If the symptoms are not serious and will recover on their own after a while, it may be due to heatstroke caused by too hot weather. If the condition is more serious and the dog is in poor spirits and is accompanied by vomiting and diarrhea, it needs to be sent to the hospital for examination and treatment in time.