If you have the means to conduct a titer test on your animals, it can provide valuable information about the effectiveness of a single round of vaccines for their entire lifespan. It’s worth noting that veterinarians may not always share this option since they typically recommend annual updates. However, it is a legal requirement to have the rabies vaccine administered every year or every three years, depending on the jurisdiction. When dogs receive vaccines throughout their lives, it becomes crucial to identify which vaccines can be discontinued. For example, parainfluenza is becoming less necessary for dogs of all ages, except perhaps during the initial stages of their life. Older dogs primarily need vaccines for rabies and parvo. Bordetella may also be important unless you frequently board your older dog, although that is less common.