A failed RNATT is stressful but not the end. Here's exactly what it means and what you need to do.
What a failed result means
The RNATT measures the level of rabies antibodies in your pet's blood. The minimum acceptable result is 0.5 IU/ml. A result below this threshold means the rabies vaccination did not produce sufficient immunity. Not that your pet has rabies, and not that anything is irreversibly wrong. It means the test has not passed and cannot be used for the import permit application.
What happens next
You need to revaccinate your pet with an approved rabies vaccine and then repeat the RNATT blood draw. The 180-day waiting period will restart from the date the new sample arrives at the laboratory. This is unavoidable. There are no exemptions or workarounds.
Before repeating, talk to your vet. A low result can sometimes be caused by the timing of the blood draw relative to the vaccination. Drawing blood too soon after vaccination, before the immune response has fully developed, can produce a low result even in a well-vaccinated animal. Your vet can advise on the optimal timing for the repeat draw.
The timing question
If this is your pet's first rabies vaccination, DAFF recommends waiting 3-4 weeks between vaccination and the blood draw to allow the immune response to develop. Pets with a history of regular rabies vaccination may be able to have blood drawn sooner, so check with your vet. When repeating, ensure your vet sends the sample to the right lab. See Kansas State vs Auburn for a comparison.
How common is a failed result
Failed RNATTs are not common in pets with a current, complete vaccination history. They are more common in pets that were vaccinated for the first time shortly before the blood draw, or in pets where the vaccination was administered incorrectly. If your pet has been regularly vaccinated against rabies for years, the chances of a failed result are low.
Does a failed result affect your timeline significantly
It depends on where you are in the process. If the failure happens early and you have time before your planned move, a restart of the 180-day wait is painful but manageable. If it happens close to your planned departure, it will delay your move by approximately 6-7 months. This is why starting the RNATT process as early as possible gives you the most buffer.