Most vets need to revisit how to interpret titer results. A low titer does not mean the dog needs to be revaccinated. It means that the dogs system has not had a challenge against that particular disease in a while. In other words, a low parvo titer means your dog has not been exposed to parvo so has not produced antibodies against it.
A dog with immune supression might have low numbers, but they should be low across the board because the vaccines never did that dog any good, and revaccinating a nonresponder doesn’t help, since they are not capable of responding to a vaccine. These dogs get sick from everything , never thrive, and usually die from something young.
