If your dog does not eat two days in a row it's generally a good idea to take him to your veterinarian and make sure he is okay. Dogs like consistency, so sometimes feeding him in a new place, at a different time or in a new bowl may cause him to not eat. Occasionally a food may not be stored properly or might be too old and the fats have started to go rancid, which can lead to feed refusal. Sometimes when the weather is too hot your dog might not want to eat. Leading the list is chocolate.
Chocolate contains a substance called theobromine, which is toxic.
Never feed chocolate or food containing it to your pet. Also, never feed an onion to your pet as large amounts can destroy your pets red blood cells causing anemia. While many people give their dogs raw meat, fish or poultry products these meats contain bacteria or possibly parasites, which are killed in the cooking process. For this reason raw meats are also not recommended. Softer bones such as those from pork or poultry should not be fed as they can splinter and puncture the intestines.