The consequences of giving your dog an expired vaccine are: firstly, non-toxic and harmless, your dog will not experience any discomfort or abnormality after the injection, but your dog will not produce antibodies either. Secondly, toxic and harmful, changes in the environment or substances in the vaccine vial after the vaccine has expired may produce toxin-causing substances or cause the virus to return with infectivity, eventually leading to poisoning or illness in dogs.
