Why bordetella is every six months when everything else is every three years

Two clocks, not one

A dog boarding in New York City is carrying two vaccination clocks at once, and they run at different speeds. Rabies, distemper, hepatitis, parainfluenza and parvovirus are all checked against a three-year window. Bordetella is checked against a six-month one. A single expiry date on a pet's file would let the shorter clock run out while the longer one still shows years of cover left, which is exactly the failure the two-clock rule exists to prevent.

This is the City's rule, not this lodge's

It is worth being plain about where this comes from, because it is easy to assume a kennel invents its own list. It does not. New York City's Administrative Code, in the section that regulates boarding kennels, sets both the list of vaccines a dog needs and the interval for each one. Every boarding kennel in the city works from the same list and the same two intervals; this lodge has to see proof of it before a dog stays, and says so rather than presenting somebody else's rule as its own. Here is the same table the vaccination page prints, with the source of each row named beside it.

Why a rabies certificate with years left on it tells you nothing about Friday

This is the practical trap the two clocks set. A dog can have a rabies certificate showing two years of cover remaining and still be unable to board this weekend, because its bordetella vaccination lapsed last month. The two facts sit on the same piece of paper in most owners' minds, because most owners only ever think about rabies. The booking form checks every vaccine on the list separately against the dates of the actual stay, and tells you which one is short before you have paid anything, rather than at the desk on the day.

Why the interval is shorter for one vaccine and not the others

Bordetella is treated differently because the immunity it provides does not last as long as the immunity behind the three-year vaccines, which is the ordinary veterinary reasoning for the shorter interval rather than anything particular to this lodge. It is also worth being clear about what the vaccine does not do: it reduces how often dogs catch kennel cough and how badly, and it does not stop it outright, because kennel cough is caused by several organisms and bordetella is only the one the vaccine is named after.

What proof looks like, and what happens if your dog cannot be vaccinated

The City accepts a vaccination certificate, a health certificate, or a bill or receipt from your veterinarian showing what was given and when. If your veterinarian has written that a vaccination is contraindicated for your dog, that letter is what the rule asks for in its place, and it goes in the same upload box as everything else. None of this is a form this lodge invented; it is what the Code already provides for.

And then it is deleted

The document itself is kept for twelve months after the last day of your dog's stay, because that is the period the record-keeping rule sets, and then it is deleted rather than archived. Knowing the two clocks and where the rule comes from will not make either interval move, but it does mean nobody is surprised by a bordetella lapse three days before a trip when the rabies certificate looked fine.