Depending on the vaccine, initial doses protect for three weeks to a year. Thereafter, some vaccines last longer than that.
The American Animal Hospital Association, or AAHA, makes recommendations about vaccinations and senior dog health care by relying on evidence-based medicine, i.e., rigorous, high-quality research, not opinion. Their guidelines are published at AAHA.org.
AAHA recommends “core” (essential) vaccinations for common, serious viral diseases, including distemper, adenovirus, and parvo. Most studies show that dogs that receive the initial vaccine series and a booster within a year retain protective antibodies for at least three years.
Rabies, another core vaccine, is boosted by the date shown on the rabies certificate. After initial vaccinations, that vaccine, too, is often repeated every three years.
“Noncore” vaccines protect dogs from diseases they may be exposed to based on geography and lifestyle. Examples are Bordetella, leptospirosis, and Lyme vaccines, all of which protect against bacterial diseases. Research shows that duration of immunity isn’t as long for bacterial diseases as viral diseases, so AAHA recommends vaccinating dogs at risk for these diseases every year.
AAHA doesn’t recommend withholding vaccinations from senior dogs, because there is no evidence to support the practice. Indeed, elderly pets, like elderly people, often have worse immune function than young and middle-aged adults, so vaccination boosters may be even more necessary in this age group.
I suggest you follow the recommendations of your veterinarian, who is in the best position to know your dogs’ health and vaccine requirements.
You’re wise to plan ahead to ensure that your cats are happy with their new family member. Start by carrying a baby doll around in your arms. To familiarize your cats with baby scents, apply the products you'll use on your child to the baby doll, and let the cats sniff. Record baby sounds, and play them daily.
Accustom your cats to the sight, sounds, and smells of a real baby by inviting a friend with a baby to visit.
After your child is born and while you’re still in the hospital, have your husband take home a blanket or cap your baby used and let your cats sniff it.
Once the baby comes home, remember to spend time petting, snuggling, and talking to each of your cats so they'll know you still love them.
Minimize parasitic infections by keeping your cats indoors and using a preventive, such as Revolution or Advantage Multi, that targets fleas and intestinal parasites, particularly roundworms and hookworms, both of which can infect children. Keep baby toys separate from pet toys.
Supervise young children’s interactions with pets, teaching them to treat pets gently and with respect.
Perhaps my most helpful advice is to download a free copy of the outstanding “Pet Meets Baby” book at AmericanHumane.org.