Hello & welcome. I am Dr. B, a licensed veterinarian and I would like to help you with your wee ones today.
I am glad to see you are having Bailey tested for herpes virus. Now you haven't noted which herpes test the swab is going for at Glasgow (since this lab can test for this virus via virus isolation and via PCR). I would just note that since Bailey has had chronic signs and this is an intermittently shed virus, I would strongly advise that you have the sample tested via PCR. Because where virus isolation requires viable virus to be picked up by the swab, survive the post, and then infect cells in the culture media; PCR can pick up the virus (living or dead) by detecting genetic material (even in tiny amounts) on the swab. So, for chronic kitties who will have a lower viral shedding load, PCR is the better test to confirm if they are carriers.
So, this would be the ideal test to do right off the bat. But if you have already sent the sample for virus isolation (and it cannot be changed with a wee phone call), then I would suggest that PCR be added-on if you get a negative isolation. This will ensure you are not getting a false negative and identifying herpes present if it is sneaking around in Bailey's body. Just to note, if your vet did take the swab after using any stain in his eyes (even if they took an oral swab as they should), then we'd want to resample before testing with PCR since the stain interferes with the PCR test.
Now in regards XXXXX XXXXX question about your other kitty, truth be told, it is quite likely that your other kitty is also a carrier of feline herpes virus. It is a virus that is endemic in our kitty population and it is a sneaky one! Once infected (most often from mum when they were wee but she could have also picked it up from Bailey), cats are life long carriers of this virus.
Despite having it for life, this virus isn't one to cause constant issues and more often it lies latent in the body arising only when the cat is suffering with an immunological or environmental stress (ie I have a cat patient who breaks with corneal ulcers like Bailey whenever his owners start packing for holiday, and I had another herpes carrier patient that once popped up with corneal ulcers a few days after he was in a car accident). So, many cats will carry this virus and we will not be any the wiser it is there until their immune system lapses enough to let the virus cause mischief and signs like you are seeing with Bailey (or they may have a wee sneeze or runny nose until their immune system gets the virus back under control).
So, it is quite possible for both cats to have herpes without your other cat showing signs. And a seemingly healthy secret virus carrier (like her) is actually more common then chronically affected cats like poor wee Bailey. Therefore, we have to be highly suspicious that both your cats could have herpes but understand that only Bailey may show signs of it. And in regards XXXXX XXXXX we'd have to consider that he may just be a more sensitive soul (with a weaker immune system due to genetics, early exposure to the virus when he was little, or another issue) then your other kitty.
Therefore, it is good to have him tested for the herpes virus at this stage and with his being chronically affected, it would be ideal to have Glasgow test his sample via PCR to make sure you determine if he is truly negative or potentially positive for this virus.
I hope this information is helpful.
If you need any additional information, do not hesitate to ask!
All the best,