What a titer measures
A blood sample is tested for antibodies against a specific disease. A result above the accepted threshold suggests the animal is still protected. It says nothing about diseases not tested for.
Where it is accepted
- Dogs: distemper, adenovirus and parvovirus (the DHPP core). Many vets accept a protective titer instead of the three-yearly booster, and some kennels do too.
- Cats: panleukopenia. Titers for the respiratory viruses are less reliable, so most vets still booster FVRCP.
Where it is not
Rabies. In the United States, a rabies titer does not satisfy vaccination law, and no kennel, county or airline will take it instead of a current vaccination. Rabies titers exist for a different purpose: some countries require one (the FAVN test) before a pet can enter, in addition to vaccination.
Kennels and daycares
Policies vary. Some accept a titer letter from your vet for DHPP; many require the vaccination regardless because it is simpler to check. Ask before paying for the test.
Keeping the result
A titer is a lab result: log it with the date and attach the report. Vets and facilities will want the number, and it is due for repeating in a year or three like the vaccine would have been.
Sources
Rules and guidelines change, and businesses set their own policies. Confirm with your vet and with whoever is asking.