Sometimes I think we do it on purpose. Really.

Wait, I started in the middle of the discussion. Let’s try it again.

We get questions a lot about vaccines. How necessary they are, how often they need to be given. There are some very vocal folks who are adamantly anti-vaccine. I’m not going to directly enter that debate, but I do want to discuss some of the recommendations we make for vaccines, and try to explain the reasoning behind them.

When you call for a first puppy or kitten appointment, we are thrilled. We love little ones. They brighten our day. But that brightness is not the reason we insist that you bring them back every 3-4 weeks until about 5 months of age. Really. I swear. Here’s where some of the confusion starts- so bear with me.

Puppies and kittens generally should start getting vaccines at about 6-8 weeks of age. This time is set because at that point, the maternal antibodies are starting to wane. What are maternal antibodies, you ask? Glad you did. Maternal antibodies are the infection fighting force that babies get from mom- generally in the first milk, or colostrum. If a female dog or cat was properly vaccinated, her body makes the antibodies to keep her safe from things like rabies, and some of those antibodies go out through the colostrum and into the puppies or kittens. There’s a narrow window of time that the babies can absorb these antibodies. Once they are absorbed, they offer some protection to the baby.

OK, so far so good. Here’s where we come in. Those antibodies don’t last forever. And the babies’ immune system isn’t making more that way mom’s does. So we need to teach the babies’ immune system to make antibodies. How do we do that? Vaccines. Immunizations. Most youngsters will have lost the protection from mom by about 6-8 weeks, so that’s when we start the vaccines. Trouble is, there can be some of mom’s antibodies still floating around causing trouble, and not allowing the baby’s system to properly learn how to do this on its own. So we need to keep the baby protected, and remind the immune system of its job, by boostering the vaccine every 3-4 weeks.

Everyone should have an immune system mature enough to be trusted by about 4 months of age. Therefore, the vaccines we give when they are over 16 weeks should last for a year. So why don’t we just vaccinate at 16 weeks and be done with it? Good question. First- we’d be leaving that baby unprotected from life-threatening diseases during the interim. And, how do we know for certain that mom was vaccinated properly, or that her system was working well enough to pass antibodies in the colostrum, or that the baby got enough colostrum at the right time? Right, we don’t. So we play it a bit conservative, and booster vaccines.
OK, say your breeder told you that the 12 week old puppy you are buying has had three distemper-parvo vaccines. Are you done? Nope. Remember, the number of vaccines given is less important than the timing of the vaccines, including the last one- which should be given at 16 weeks or older.

Having said that, the DHPP vaccine for puppies and the FVRCP vaccine for kittens should be given at least twice, 3-4 weeks apart. Feline leukemia vaccine must be given twice, 3-4 weeks apart to ensure immunity. It’s just the way the vaccines work on what we call naïve (previously unvaccinated) pets. Rabies and bordatella (intranasal) are a little different- they create good immunity after one dose.

See? I think we do it on purpose- make vaccine schedules as confusing as possible.
Wait ‘til we talk about timing of adult vaccines.