When we talk about vaccines of dogs*, we tend to split them into “core” and “non-core” vaccines.

(*The same applies to cats. I use dogs by default for posts like this, which sometimes gets me an earful, but I’m not actually ignoring cats.)

Core vaccines are those that every animal should get (e.g. rabies vaccine in areas where rabies exists, canine parvovirus in areas where dogs exist). Non-core vaccines are those that aren’t required by every dog, or that are less convincingly needed in every case.

Non-core vaccines are also often referred to as “lifestyle vaccines,” because the nature of the dog’s (or cat’s) lifestyle can put the animal at more or less risk of exposure to a disease, which affects the relative need for vaccination. Respiratory diseases are a great example. All dogs are at some degree of risk, but the risk is much higher in dogs whose lifestyles create more dog-dog contact (e.g. going to daycare, boarding, off-leash dog parks). That’s a good way to think about how to prioritize vaccination for an individual dog, but it misses a big part of the disease prevention equation.

When I’m assessing the need for vaccination in a pet, I think about two main things:

  1. Risk of exposure. The lifestyle aspect covers this.
  2. Risk of serious disease. This often gets ignored.

Some dogs are at higher risk of severe disease or death from respiratory infections. I’d put senior dogs, brachycephalics (i.e. flat-faced breeds), pregnant dogs, dogs with pre-existing heart or lung disease and dogs with compromised immune systems on that list. I’m more motivated to protect them because the implications of infection are higher, even if their risk of exposure may be fairly low.

Take my two dogs as an example (again):

Ozzie is 1.5 years old and healthy. If he gets a respiratory infection, most likely he’ll have transient disease and, while it will be annoying (for him and us) and I’d like to prevent it, odds are quite low he’ll suffer any serious consequences.

In contrast, Merlin is an 11 year old dog with chronic lymphoid leukemia who’s been getting chemotherapy for about 2 years. He’s doing really well, but he has a significant chronic disease and he’s old. If he gets a respiratory infection he’s at much greater risk of dying than Ozzie.

If we look at lifestyle of these two dogs, they’re similar, since they do everything together. The exception is in the summer when we go to a cottage for 2 weeks. Since 2 weeks with Ozzie at a cottage isn’t much of a vacation for us or Merlin, he went to a local day care for part of the time. (An exhausted Ozzie is a good Ozzie, and he often came home close to comatose, which was perfect.) So Ozzie has a major additional lifestyle risk factor, therefore he’ll get a respiratory vaccine again this summer (both because of the risk and because the day care requires it).

Merlin doesn’t have that same direct exposure risk, but he has some added risk through being exposed to Ozzie. Should he get a respiratory vaccine? If we just look at his lifestyle, we’d say no, he’s pretty low risk for exposure. However, his higher risk for severe disease increases my motivation to vaccinate him, and he’ll likely get a respiratory vaccine this summer at the same time Ozzie does.

Lifestyle is definitely important to consider, but we need to make sure we don’t just focus on the dog’s lifestyle and consider the dog (or cat) as a whole.