Re: Great question...on Parvo/Dog Parks....Thought I'd Share
It is safe to say they dont have immunity from the mother, and they dont have immunity from a vaccination so do you feel that at some point they were exposed to a lower level of the parvo virus or have they had it in the past?
They're six years and almost three years old, so you're right, they don't have maternal immunity any longer.
They haven't had parvo but I'm quite sure they've been exposed to it on a lower level pretty much anytime they leave the house, given the endemic nature of the virus. As well, they've been at vet's offices, dog shows, pet stores, walks around the neighborhood, other breeders' homes, etc. - so not only have they been low-level exposed to the wild virus, but they've also been exposed to shed virus from recently vaccinated dogs.
It's not a practice I recommend for everyone - there are many other things I do to ensure my dogs have optimal vibrant health and immunity, and I am always vigilant for signs of parvo in puppies - but it's certainly testamentary that lack of vaccinations is not always a death sentence.
Now that I think of it, I have another almost three year old who only had one vaccination but I don't remember what age - either six, seven, or nine weeks old - I'm leaning toward seven weeks.
How can someone know that their dogs have a natural immunity to something?
Same way they know their dogs have vaccine-induced immunity to something.
Do titer tests show that if they have never been immunized?
Yes, they can - titers show circulating antibodies, and if a dog has antibodies they have immunity. (Some feel that only certain levels of antibodies are "protective", but that's debatable.) If a dog doesn't have antibodies, they may or may not have immunity - it may just mean that they haven't been recently exposed to the virus, so haven't needed to produce antibodies.