Thank you for your answer. I still haven't had anyone really address my question so I wonder if I'm not making myself clear. I'm sorry if I'm not. When they say it's "likely" Marek's, that does not sound as if they've put the tissue of a tumor or whatever on a slide, added some agent that turns some color (only example I could think of) and saw something that says, "YES, this color indicates the Marek's virus in this tissue!" Do they do that or is it only visual? Considering that there are several diseases that can cause weird livers and cancers other than MD. Gatherings of odd cell growths are not always cancerous, either.
Do you see what I'm saying? Though the virus may be common, it seems that folks jump to the MD conclusion so quickly when other things can mimic MD. A bird limps and someone screams, "Mareks!" when all it did was sprain its leg.
I did read all of Jennifer's FAQ so part of what I'm asking sort of was prompted by that long read. I know my birds are MG/MS free, which everyone says is near to impossible, but those tests seem more definitive than the ones for MD, they are not visual observations. All of this reading is making me feel hopeless and then, when I see supposedly respected breeders selling and showing birds from their MD-positive flocks, that makes me insanely angry, to think they are helping to cause all this heartache we are seeing on this thread and others. I'm going to have to find a way to feel about this, a philosophy about it, so I can stop obsessing over it. I don't feel as if I'm helping here.
Oh boy, finding a way to feel about this has been a journey I've been on for two years now. Every time I think I understand something, another paper or idea comes along that makes me more confused than ever. I couldn't find a concise website with ANSWERS in one location so I started to make one myself. It took a year to get it to where it is today. A year of researching at least once a week, sometimes more often. And it's still confusing, and maybe wrong in places, but I am doing the best I can. I have to laugh a little, or I would cry....
When an avian examiner looks at a bird post-mortem to determine cause of death, they take into consideration symptoms shown in life, and gross necropsy results. Gross necropsy is what you and I can do at home; carefully open the bird and do a visual exam. Now, avian examiners, such as those at state labs and well-educated avian vets, etc, know the very subtle tell-tale symptoms of various diseases by sight. So-- most of the time, the symptoms are considered, the bird is opened up, examined visually, and a 'best guess' is taken. If any given disease is suspected, only then are further tests sometimes run (for example if bird symptoms are respiratory and upon exam MG/MS is suspect, most labs will test for it since it is, as you mentioned, a pretty clear cut test). However, testing is up to the examiner, and/or up to the client (you, me, the next chicken keeper) to request. Some labs will test suspicious tumor tissues/nervous tissues of Marek's is suspect,
and some will not unless the customer requests it.
Unless the necropsy report specifies that specific tests were done (such as PCR), then one must assume it was
visual only.
Though other testing is available, I have personally not seen any lab or vet test for Marek's in any way other than the following:
- Visual necropsy
- Examination of the sciatic and sometimes vagus nerve (looking at samples of the nerve under a microscope for lesions, which are not always present or even visible!)
- PCR testing.
Has anyone else here ever had any of the other testing done on their bird? Do any of the labs still do cultured tests at all?
I see from Karen's scans that titration testing has been done in the past. Has anyone ever had this test done on a bird by a lab??
I am just a layperson so maybe these are stupid questions, but I really haven't read or seen these done in the last few years that I've been researching this...
It is worth mentioning a few things:
1) A lot of people
do jump at "OMG it's Marek's" without any sort of professional exam of a deceased bird. It's one reason why the "Marek's look-alikes" part of my FAQ is so darned long (and could be longer...)
2) Some of us here have had birds tested that became ill after we had a Marek's confirmed case in our flock. We were sure it was Marek's. Then the tests were negative. This could be for two reasons-- a) The bird had a look-alike disease, and/or b) false negatives.
3) Despite all this, Marek's is pretty common. But as it has been so aptly put... it's like chasing a ghost. Is it Marek's? Is it not? Nothing about this is straight forward other than a few base facts.
