"Of course ELISA and WB have failure rates."
Thank you for at least admitting that, as many are still steadfast in their belief that the test is definitive (& yes, human docs especially).
"But so does microscopy for the reasons I stated above, unless we are talking about an acutely infected person with unusually high numbers in the bloodstream, or a badly relapsing person with the same."
Here is a study that takes blood from Lyme victims early on & off season. They are able to use the blood for RNA PCR & confirm a borrelia infection. This means it has to be in the blood, albeit perhaps not in large quantities & not well suited for microscopy. I agree that early infections are most likely not worth the time. It is the long term & chronic ones, that have been sitting around with a negative diagnosis, that can possibly holster the rewards of microscopy.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4139787/
"Two other issues of note. While there are indeed non-pathogenic species of Borrelia, implying that we should desire a test that could detect positivity for all species and/or strains is silly. Because you can bet that what follows will be a lot of unnecessary treatment at the insistence of uneducated patients and paranoid doctors."
I agree. BUT, lets take this example.
-Patient comes in with odd ball symptoms that overlap Lyme & no joint pain.
-Patient (animal or man) receives negative or inconclusive blood tests & you deem safer not to treat.
-Patient comes back in months with degrading health & more overlapping Lyme symptoms & still no apparent joint pain & a 2nd Lyme test mimics the 1st.
As a veterinarian you are not sure of a Lyme diagnosis, do you still prescribe antibiotics at the risk of causing resistance & damage?
Reports are actually coming in from all over the world that the spirochetes can be seen via microscopy if you vacuum seal the wet drop preparation & wait a few hours, then they start exiting the RBC's. There is now even a readily available & low cost preparation to balloon the RBC's in order to see the spirochetes directly within the RBC's (I provided you with the paper & recipe). Does your curiosity not inspire you enough to even check via microscopy? It seems like it is easier to just send them out with their Doxycycline or tell them your sorry since the test came out as it did?
Take a gander at this scientist who was stricken with mysterious symptoms & a negative Lyme tests that did not afford him abx. As is typical with many Lyme sufferers they were bounced around from doctor to doctor with no answers. He had nowhere to turn, but toward his microscope & look at what he is finding. Two pages worth of symptoms & a plethora of bacteria in his blood that he can culture. This is not rocket science, & he can easily see that his Lyme symptoms is caused by massive amounts of spirochete bacteria present in his RBC's. So rather than being in the dark without microscopy, it afforded him the ability to take matters into his own hands & take the next step.
"OP has been reading too much Horowitz. Diagnosing "chronic Lyme" is still extremely controversial."
Many paradigm shifts are controversial in the beginning & many don't really care to look past what they have been told is the correct protocol to follow. It is the easier road to follow.
"Secondly, one of the biggest differences between human and veterinary medicine is cost. You can do all the fancy diagnostics on the humans and insurance will foot the bill. We use ELISA snap tests because they are cheap and have a decent measure of sensitivity when the results are put in context with exposure and clinical signs. We can't expect our clients to shell out hundreds or thousands for culture, Western, PCR, FISH, etc nor can we rely on microscopy alone for the reasons I stated above."
I can agree with expensive tests on animals, but how expensive is it for you to look under a microscope the next time this type of case (as I listed above) comes along? Would you have the curiosity to check?