Here's what you should do:
* Contact your veterinarian immediately. They will be able to assess the situation and provide appropriate guidance.
* Describe the symptoms in detail. This includes the severity of the reaction, when it started, and any other changes you've noticed in your dog's behavior or health.
* Follow your veterinarian's instructions. They may advise you to bring your dog in for an exam, administer medication, or recommend other steps.
Possible symptoms of a vaccine reaction can include:
* Swelling at the injection site
* Lethargy
* Loss of appetite
* Vomiting
* Diarrhea
* Fever
* Hives or itching
* Difficulty breathing
It's important to remember that even though your dog is 14 years old, they are still susceptible to vaccine reactions. Never hesitate to seek veterinary care if you suspect a problem.
Please note: I am not a veterinarian, and this information is not a substitute for professional medical advice.