I don't think so, as stated by eggcessive... and they likely won't test for anything they haven't been instructed to do so or that they aren't looking for.Will Marek's show up on a choanal swab test?
Have you checked him over for injury? If that WERE it, the amount of time it takes to walk would depend on a lot of things like type of injury and if it continues to be over used or not. But I would expect to see some attempt to stand up and such... Ehh... hard to say if a rooster in shock would crow or not since every animal is different. But I would consider crowing to be a positive sign.
You say bacteria in your chickens throats is a problem you have... is the first time testing it? Or what makes you think bacteria and not yeast infection (sometimes caused by antibiotics) like thrush or something?
Have you seen this... sometimes it can be a helpful tool. What I like the best is that it has a list of things I might not realize are symptoms so it helps to know what to look out for. (wow I wonder what made my text size change?)...
http://www.poultrydvm.com/views/symptoms.php
One of the things that comes up with the mouth thing (other than canker) is vitamin deficiency... what are you feeding on a regular basis, including treats and supplements?
Maybe you are keeping him too hydrated sub Q and should give him a chance to seek his nutrition from the correct source?

Are you actually working for vet? Or where did you come up with all these things to do? Sometimes allowing an animal to recover... might be a really good option... they were created with ALL the necessary stuff to do so... Self healing... actually science REALITY! (not fiction) Just a thought.
