What is Marek’s with Dr. Morishita
In this deep-dive episode of the Poultry Nerds Podcast, we're joined once again by our resident poultry veterinarian, Dr. Morishita, to tackle one of the most misunderstood and hotly debated topics in the poultry world—Marek’s Disease.
We break down the science behind this deadly herpesvirus, how it spreads through feather dander, and why vaccination is the only real defense. Dr. Morishita explains the four main symptoms of Marek’s, how to identify them, and whether it's even possible to maintain a Marek’s-free flock.
Plus, we get answers to your biggest questions:
Can vaccinated birds spread the virus?
Is turkey dander protective?
Do herbal remedies work?
How can you safely necropsy your own birds?
Can you test for Marek’s in a live bird?
🔬 Whether you're a backyard poultry keeper, gamefowl breeder, or raising exhibition chickens—this episode is packed with must-know facts that could save your flock.
-
Jennifer: 0:24
Welcome back, poultry nerd. We are here again with I guess, our resident poultry veterinarian at this point. Dr. Morshita. So welcome back. How are you doing?
Dr. Morishita: 0:40
I'm doing fine. And how are you both?
Carey: 0:45
I'm doing good.
Jennifer: 0:46
Good. We're good.
Carey: 0:47
I'm excited about today's topic because today's topic is one of those that you hear so much back and forth and back and forth that nobody will ever say anything definitive about it because in my opinion, they don't really know. And there's very few people that have actually studied it, that, in my opinion, are qualified to speak on it. And they usually don't want to. So I'm excited that we get to talk about it today.
Jennifer: 1:23
And the topic is Merrick's disease, so we are gonna find all about it. And I have my
Carey: 1:33
aluminum cap on.
Jennifer: 1:35
You're gonna what?
Carey: 1:37
I said I have my aluminum cap on my tenfold hat. I'm ready to go today.
Jennifer: 1:44
So I listened to another discussion with a scientist a couple weeks ago about it and actually feel like I have a grasp on what it is. Will you explain Marck to us please?
Dr. Morishita: 2:04
Okay. So Merrick's disease, actually, and we should be concerned about it because it's a very important disease in the poultry industry, and many years ago is one of the most important, and it still is. I know that we have AV influenza happening to us right now, but this Marx is always there. So Marx's disease is caused by an disease agent called the virus, and it's a herpes virus.
Jennifer: 2:36
Is it just one virus?
Dr. Morishita: 2:38
Yes. Okay. It's a herpes virus. And as we talked about in the past, remember we talked about avian influenza? And how. You could it's like a, it's called an RNA virus and that's how it has a lot of mutation. This week the herpes virus is caused by a DNA virus. And this particular virus is very hardy in the environment. So guess how it spread? Now this one is very unique in that it is spread chicken to chicken by feather dander feather dutch, which is literally
Jennifer: 3:17
everywhere.
Dr. Morishita: 3:17
And it stays in the environment. And the other interesting thing is that if you get it on your clothes, you can also pass that on. They call it indirectly,'cause you're not a chicken, but you can pass it on if you got contaminated clothing and things like that. Actually. That's one of the reasons why in the commercial poultry industry, we wear coveralls when we wear hair nets because that virus can survive in the environment for probably up to four weeks, sometimes even month, a month or so. So it's very hardy. So if you know your birds get into a environment or you handle an infected birds and you don't wash that clothes and you keep on using it for other birds or you, when you're working with new chicks, potentially there's contamination.
Carey: 4:09
So let me ask this. Is merricks something that could be inside of the chickens in their DNA all the time and something happened that makes it to where it's full formed and obvious that's what's wrong and the bird gets sick? Is it like a hidden thing that can come out or does it just happen?
Dr. Morishita: 4:34
It's there and it comes out and maybe the good example I can give, it's a herpes virus. So if we think about people with herpes virus, right? Cold sores around the mouth.
Jennifer: 4:45
That's
Dr. Morishita: 4:46
a herpes virus. So the herpes virus stays in your body. And like in people, if you get stressed, people that have cold sores around the mouth. So birds also, if they get stressed maybe or something triggers it, they can release that and they can start shedding that as well. So what they always say once, once you have the chickens, once you have a herpes virus, you're like a potential known source of that. So let's say I like to add new birds into my flock, right? So your bird might not show any sign, but it might be carrying that mareks. It hasn't shown any signs at all. All this feather, Dans coming out, your little feather dust, you bring a new bird into that area and lo and behold, a bird, that bird might develop merrick's disease.
Jennifer: 5:39
Okay. Okay. So what are the symptoms then?
Dr. Morishita: 5:46
So that, yeah, that's a good question because the main thing that you wanna know is what causes it? What are the signs? This is what you're gonna look for. So they say that it can affect the, they call it the peripheral nerves. So those are nerves that are like going to your arm. The, their legs or wings. Okay. Those are the peripheral nerves. And, normally one of the classic signs of Mareks disease is you see a bird down lame and has one foot forward and one backwards. Like it's almost doing the split on the ground. That's almost like the classical sign of Mareks.
Jennifer: 6:23
Okay.
Dr. Morishita: 6:23
And often, we have chickens and they are like little cannibalistic, a little pecking order. So when they see one of their fellow flock mates down on the ground, usually they'll jump on'em, scratch the back. And you see a lot of them, them de feathered and that bird dies eventually'cause they all kind of gang up on that bird'cause that bird is down. So we see a lot of the mortality. I've seen like some people, that I talked to with Merrick's disease and. If you had that bird alone, it may be recuperate after seven days, but most times, we keep chickens in a flock, so they will go down. Okay. The other signs that you can see because it affects like the nerves of the body and again, that's coming off the central nervous system, that's a spinal cord. Some of them might have lame necks. You might just see them on the ground. Okay. So that's one sign. The other one is only if you start pulling feathers off, like those people that are butchering and slaughtering chickens. If you pull the feathers off, you might see like little bumps where the feathers were. That's the skin form of merrick's disease. We call it skin osis. And it almost looks like a. I would say little bumps, all with the feathers attached to the skin. And that's the skin form. So sometimes birds may show that sign and you don't see it at all because they have the feathers covering it. Only if you butcher them or, slaughtering them for home use and stuff. You might see them. We see sometimes that, like in the large processing plant, when we have the large commercial flocks affected, and then the other form is on the eyes and we call that gray eye disease. So that's the third form of Mar's disease. And that's when the tumor cells invade that colored part of the eye, which we call the iris. And so normally, you know that chickens normally have a, an iris of like orange, yellow. And when they have merits, these tumor cells will invade the iris, and then you'll see it as gray, grayish blue. And they often call that gray eye disease like a common name when you see that. So the birds might not die, but you might see your birds, the flock and some of them have one gray eye, some may have two. But that's how you can see that potentially you have had merricks through a flock. If you see several birds with that color V Okay. And the fourth and most devastating form is the internal tumors that grow throughout the bird. So when you see a bird that's dead and you open it up and it's very good if you want, I. Not, like we talked about last time, when there's a big mortality that you're gonna open up birds, you wanna call a professional, but sometimes you might have one or two birds that die and it's good if you keep chickens. You wanna find out what's going on if you don't have a nearby lab, but you always try to take your lab to the lab if possible. But you can see all these like nodules in the liver.'cause the liver is normally dark red, but you'll see this yellowish white nodules or spots, throughout the liver. And it's hard. And that is part of the tumors that are growing. So you see it on the spleen and those of you that if you remember like you have cut up chicken before, like the spleen is located between the proven ventriculars and the gizzard. The proven ventriculars is a real stomach. And there's a little organ, a reddish organ that's like oval shape, that is a spleen of chicken. We know that it's probably about the size of your first digit or size in a. Adult chicken. But if you've got Merrick's disease, that little spleen can be like two to three times large, and it has those yellowish white nodules in there. So those are immediate signs that you've got marck. So there's usually tumors throughout the body, and that really is what kills the birds. So just remember there's four signs or clinical signs in the birds with Mars, the peripheral nerves. So they get lame and they have different stretching, one leg out, stretching, one leg back. They have the skin form that's bumpy skin where the feathers join the skin. Then they have the gray eye, and then they have the tumors. They can have one or all four of those signs. So you always have to be vigilant of that. And because it's spread by feather dander, one bird can spread it to the whole flock. So that's one disease that we, so it affects that Always wanna prevent It affects, go ahead. Sorry.
Jennifer: 11:37
So it sounds like it affects a lot of different things, the skin, the eyes, the liver the spinal cord. So it's polygenic because it affects several different parts of the body? No,
Dr. Morishita: 11:52
It has ability to spread'cause remember it's tumors, so like a tumor cell can spread throughout the body and then it can go to the different organs,
Jennifer: 12:02
okay. Let's see, how do I wanna say this? So how does the vi the vaccine work then against the virus? Okay,
Dr. Morishita: 12:12
And you brought up a good point because there is no treatment for Marx, right? So the only way we can prevent this is through vaccine. So it's very important because you remember, once a bird gets a herpes virus, it remains there for life, right? So that is why one of the key things is that we try to get them vaccinated at one day of age in the hatchery. Traditionally it's been vaccinated one day of age. As soon as the chicks are born they'll vaccinate them for the commercial flocks. And all chickens produce commercially be vaccinated for Marx.'cause it's a devastating disease. Now I did not know that. So now some of the more, there's been newer methods and some of the. Methods we have is called in oval vaccination. That means vaccinating the chick while it's still in the egg. So in and an oval is egg. So they have these needles that inject the eggs and when the, when they're about 18 days of incubation. And we know that a chick hatches at 21, but they give the vaccination to the birds and hopefully beat the beat exposure to the, the virulent forms of Mars that are in the environment. Okay. That's why one of the big things in the commercial hatchery was vaccinating them at day one of age.
Jennifer: 13:44
So does the vaccine, oh, go ahead. Does the vaccine like prevent all of the different symptoms or just the tumors?
Dr. Morishita: 13:56
We know that the tumors, once you get the tumors, you can't save it. Mainly the vaccine is given to prevent the tumors formation because that is what's gonna kill the birds, right? Like I mentioned before, you got a discolored eye but you're still living. You got like I mentioned before, birds have the skin osis and nobody finds it because it's all under their feathers until they're gonna slaughter their birds. But they're still living. And then the one that is lame like that, like they're doing the split, there have been some cases, like I said before, like maybe after seven days, the bird may slowly recover, but we really don't keep birds individually. They're flock animals and as flock animals, their other flock mates tend to jump on them and that's how they die. But I guess if you've seen them, I've known some people that put'em in a sling if they wanted to save their pet chicken,
Carey: 14:53
so let me ask you this, but it's not
Dr. Morishita: 14:55
guaranteed, because they already have that, that we call it the field strain, the ones that cause disease,
Carey: 15:29
right? Yeah. So if your bird has the gray eye or the bumps on their skin what is a way that you can slow down the advancement or help prevent it to turn into the tumor form? That's deadly.
Dr. Morishita: 15:49
Sometimes they might not develop into uniforms. That's the only form they're gonna get. They can have one or all four. But so the what main way that everybody needs to is the vaccine. Get the vaccine as soon as possible. If you see those gray eye in your birds or your bumpy skin, you know that the birds that come on to your farm, if you're gonna, if you, let's say you depopulated them. Remember you got feathered dander and dust. If you restock your farm, you gotta vaccinate those birds as soon as they come on, now if you have, you don't depopulate them and gray eyes, or you just happen to butcher a bird and you see those bumby skins and you don't wanna euthanize them because of course they might be pets. And so in that case, that, something like that, then. You should vaccinate the birds that are there already.
Carey: 16:50
Now, when you vaccinate that's a live virus that they're, that the birds are being, or the chicks are being exposed to at a very small dosage. Correct?
Dr. Morishita: 17:00
That's correct. Because one of the first vaccines that was used for Marx is called an H-V-T-H-V-T standing for herpes virus Turkey, because they found that there was a Turkey strain that didn't cause these tumors that were at a protection for the chickens. Okay. Okay. So they give that, and that was hope to not develop that. Thing, the, okay, so if they got the field strain, they wouldn't develop this because there was that. We call it virulent not causing disease, the virulent HVT in the birds already. And so they were protected. So that's why it's very important. One day of age,
Carey: 17:48
let's say I have birds that are not showing any signs. And I decided that I wanted to be a responsible person ordering some birds. And I get some that are vaccinated. Will that possibly infect my existing birds?
Dr. Morishita: 18:10
'Cause it is a herpes virus too. So potentially you can spread it, but we don't wanna wait till that naturally happens because you don't know how long it would take. So it's probably, if you're gonna get any new birds, and even if you have old birds and you never had signs at all, you probably wanna vaccinate. For the Merrick's disease, the Merrick's vaccine vi, to prevent anything because, nobody wants tumors.'cause that's a death sentence.
Jennifer: 18:41
Okay. So let's back up for just a minute. So does the, does Merrick only infect chickens or is it all poultry?
Dr. Morishita: 18:52
Oh we know it's the chicken only disease, but there have been reports of it affecting turkeys. And there have been like the Japanese quail and then there have been report in pheasants and pfos. So if you tend to mix your birds that's, a caution to have. I have not, having worked with so many backyard flocks, back at, in Ohio and in California, I have actually not seen any cases of amerks in, Turkey or p fowl. But then, most, I guess it would be very rare that people have both in close proximity, walking, in the same area because of the big size difference and fighting for food. Maybe in the larger area or something, or smaller farms, you might have Mex birds, part of raising poultry, you don't wanna mex like chickens and turkeys'cause there's so many diseases that they can spread be between each other.
Jennifer: 20:01
Okay. What about ducks? Can ducks and geese get Mars?
Dr. Morishita: 20:06
No, not at this point because they're of a different order of birds and swarms.
Jennifer: 20:13
Okay.
Dr. Morishita: 20:13
But
Jennifer: 20:14
all right. We don't know that, so if you had a Marx positive flock you could vaccinate any age bird to mix it in.
Dr. Morishita: 20:28
Whenever you get new birds, you wanna try and find out are they vaccinated or not? But a lot of times, no commercial poultry are all vaccinated, like I mentioned before. But what about the backyard flock? Sometimes it's unknown, right? And you can ask the person, did you vaccinate the birds or not? But if they haven't. I would say that you could vaccinate your birds. You don't know. See, the problem is as you vaccinate them at an earlier age, you don't know if they were exposed earlier or not. Remember, we, when does it, when does that herpes virus express itself? We don't know, but we do know that once you're infected for life. So that's the thing is if you wanna be sure you can vaccinate them at any age you got at, to make sure that you vaccinate them because you don't know. Maybe you, maybe you, your flock never had herpes virus, so you probably safe, but who's to tell that they don't come out later? That's why they always say vaccinate them at end of age. But if you can't, the second best thing is to vaccinate them. Hope they didn't get exposed earlier. Hope that you're vaccinating them with the good. Virulent Turkey strain,
Jennifer: 21:42
can wild birds spread it?
Dr. Morishita: 21:46
No. Right now, all those birds that seem to be susceptible, mainly chickens, but I gave you rare cases of the other birds, they all belong to the order birds called the gala forms.
Jennifer: 21:58
The wild
Dr. Morishita: 21:58
birds, like the sparrows or songbirds belong to the order of birds called the passera forms. So a different order. So we haven't reported any of that, in other or of birds.
Jennifer: 22:15
So you, in your opinion, you don't think you can combine vaccinated with unvaccinated birds?
Dr. Morishita: 22:23
I would say I. That you should vaccinate your birds if you're gonna put unvaccinated birds in your flock, or if you don't know whether they're vaccine had vaccines or not. If you care for each bird as a pet, and you don't want it to die. Okay. But if you have okay, this is my flock. I know that they may have Mars and they might die then you can take that potential risk. It's a hard disease. It's a hard disease because you don't, if you really love every single bird, you don't want them to die, so you're gonna be vaccinating them, right?'Cause at least we don't know, because we don't know if they were expe exposed earlier, but what can, what else can you do?
Jennifer: 23:17
So what I'm hearing, because you're, it's pretty like everywhere. Is it even possible to have a Marx free flock?
Dr. Morishita: 23:29
You possibly could have a Marx free flock if you were like isolated. Maybe you got your chick, you didn't have dander in the area, you didn't expose them, you weren't expo, you yourself. Don't ca handle infected birds on your clothing and touch your new chicks or whatever. Potentially you could have a Mars free flock,
Jennifer: 23:53
but that would be rare.
Dr. Morishita: 23:57
Depends on the, what they were exposed to.
Jennifer: 24:00
So I, when you were talking about the biosecurity, I'm basically envisioning somebody going to the feed store and running into somebody that they know. And so they sit down on a feedback to chit chat with their friend and then they leave and then I go in there and buy the feedback and bring it home. That theoretically that dander could be on that feedback.
Dr. Morishita: 24:26
Potentially. But you're only gonna have maybe a few dander. It's not gonna be as much as if you actually was in that chicken house.
Jennifer: 24:35
I agree with that. Yeah.
Dr. Morishita: 24:38
So hopefully though those feed stores don't keep your, their feed bags and stuff right next to chicks or that people can sit on.
Jennifer: 24:49
Okay, so that's another point. If you go to the big box stores and they have the chicks are vaccinated. That dander is flying everywhere in the store and it's landing on you and you walk through there, are you now not taking it home?
Dr. Morishita: 25:06
If somebody with let's say I have Mar's Disease in, and I came in and said, oh, these new baby chicks, and you touch them and you hold them. Who knows? You remember, if you're close, contain that from your farm. And you brought it in, and then that little, you say, oh, buy Little Chick. And then he goes back in there and you pick up another chick. Maybe those get that on them. And then it spreads to those other chicks that are in there. So that's why vaccinating them at as soon as they're hatched. When they come out and they're a little fluffy moving around not when they just hatch, but after they've dried up a bit and vaccinate them.
Jennifer: 25:48
Once you vaccinate'em with a live virus, are they shedding it in their dander now too?
Dr. Morishita: 25:53
But it's the vaccine, it's the vaccine strain. And that virus goes in them and it has to populate in them and then go to their feather follicles. But I think Carrie was mentioning, can that vaccine strain spread throughout the flock, that's gonna take too long,
Jennifer: 26:13
okay. So that's two different things,
Dr. Morishita: 26:16
right? Gotcha. So if you got your vaccine strain, don't think that you vaccinate one. It's gonna spread throughout your flock. Your flock is protected. That's too gonna be too long.'cause it has, that virus has to go into that individual bird. That virus has to multiply, then that virus has to go to the dander and then the nearby chickens have to be there. That's too higher risk. You might as well just vaccinate them.
Carey: 26:40
What I was wondering is if I give that virus, if I get a chick that is vaccinated and put it with chicks that are not vaccinated, will those chicks get sick? Because the one that I bought that was vaccinated has the live virus inside of them.
Dr. Morishita: 27:01
The live virus that is the A virulent, so it wouldn't cause disease. So if they pass it on to the other chicks, they would be like. Feather vaccinate, but that's gonna be too long. And they could be exposed to other infected sources.
Carey: 27:19
Got it. And that could stress'em out. And that would be what would cause the tumors
Dr. Morishita: 27:25
that would cause them, yeah. If you got some infected farm and then that bird shed that virus then they have to get that virus in. And that would cause the tumors, the, if they got the field strain, the one that causes disease.
Jennifer: 27:43
Okay. So once a chick is vaccinated, how long before it is fully protected?
Dr. Morishita: 27:49
It's protected almost immediately because that virus that has the live a virulent vaccine strain like the herpes virus from the turkeys, and it goes throughout the body.
Jennifer: 28:07
Okay. Now different subtopic, you mentioned that the vaccine, HVT, tur tea is Turkey. So is there something in the Turkey dander that helps protect the chickens from merricks?
Dr. Morishita: 28:25
The herpes virus of turkeys? The HVT, that's what you get in the vaccine.
Jennifer: 28:34
So would raising your chicks with puls do the same thing?
Dr. Morishita: 28:40
I don't know because that's, that, that wouldn't be doing, because it's just like the other question, if I got one chicken, how long will it take to spread his vaccine strain?'cause he has to get it inside of him. It has to multiply and spread that way. So I wouldn't, I. They haven't done
Carey: 28:59
that research yet.
Jennifer: 29:01
So there, there are discussions. Excuse me. There are discussions that Turkey dander will help protect your chicks, and I just wondered there's any merit to that.
Dr. Morishita: 29:16
There's probably thinking in that strain if you're using the herpes virus,
Jennifer: 29:20
I personally raised my chicks and my pulps together.
Dr. Morishita: 29:25
Oh. Did you find that? Have you had any outbreaks of merricks?
Jennifer: 29:29
No. No, but I don't stress my birds, so since my birds don't get stressed how would I know that I had merricks?
Dr. Morishita: 29:43
You wouldn't until something develops, and they don't have to develop right away. They can be like later in age too.
Jennifer: 29:53
So what
Dr. Morishita: 29:54
age? Most times we think of Marxx as being a young chick disease. So they can happen as early as three to four weeks of age. You can see Marx usually about four. And traditionally we learn that, anywhere 12 weeks and younger, you 12 to 16 weeks and younger you, when you see tumors in the bird, you usually think of it as a merrick's disease. But we do know that birds that have never been exposed before, let's say I show my birds at the fair and they don't have don't have merricks, but I go to the fair and you take your bird to the fair and then you bring that bird back home. There's feather dander at the fur fair, right? And right next door we don't, we have open while your cages and sometimes it can be spread. To the next birds and stuff. Then your bird will come home and with Mars. So that's why if you tend to, you gonna show your birds and stuff like that you wanna vaccinate them, you're gonna vaccinate them.
Carey: 30:58
Lemme ask this, let's say that I have a bird that I've had, I hatched it out on my farm and it's a year old. It may have been exposed to Merricks, but it's never shown any signs or anything like that. If I take that bird and I ship it across the country Obviously that's gonna stress it out. How long, if at all, if that was going to stress it and make the merits show up and be prominent? How long would it be before I saw that?
Dr. Morishita: 31:36
If it did have merits, it could shed it because you're stressing, right? You remember it. It comes out, whatever. But in the bird itself, that's where there's a lot, like you said, a lot of research and a lot. When is it gonna, when is it gonna show?
Carey: 31:53
Would it be a week from now? The bird just starts with the eye issue and the leg issue and all that? Or is it probably, you'll get the leg
Dr. Morishita: 32:02
issue. You probably get the leg issue. If you have that, but it's unknown. And just think of it, this is like a cancer in chickens. So just like cancer in people, you never know when it comes up. It just shows up. So think of this disease as that. You have the potential, like some people have oncogenes in them And they don't know when it comes up. So that's why you need to know that potentially you might have this and you wanna prevent it.
Jennifer: 32:35
Okay.
Dr. Morishita: 32:36
Can you test for it? That's a tough one. I don't think you, you can if you have the disease, if you didn't like something like a PCR test that's quite expensive for one bird.
Jennifer: 32:53
So it, but it is possible to test a live bird or no?
Dr. Morishita: 33:01
I guess you could, but you would have to have that DNA in the bird and take some, so
Carey: 33:07
You would have to draw some blood or something like that from the bird.
Dr. Morishita: 33:10
And if that tumor is actively circulating throughout the blood, there's so much If it's there, if it's there. So even if you had a negative now, you wouldn't, even for diagnosis, you can't, there's really very hard to do when the bird is still living. There's some cases like we get some blood, we can see some of these cells, but it's not a routine thing that is done. So most of the diagnosis is through historical signs. And unfortunately if the bird dies, then we can take pieces of that liver or spleen, look at that under the microscope, and you can see the the cells, just like cancer in people. We look at the cell type. So in the chickens they're looking for this type of immune cell called the lymphocyte because that's the cell that's affected by the virus that causes the tumors.
Jennifer: 34:11
Is there any other disease that presents that way? Pardon me? Is there any other disease that presents the same?
Dr. Morishita: 34:19
There's two big tumor diseases in chickens. One was Merrick's disease and the other one is lymphoid osis, which occurs usually they say in older birds after 14, 16 weeks of age. But we know that if you see tumors in a bird younger than 14, 16 weeks, it's mareks because lymphoid osis only happens in older birds. But if you see tumors in older birds, then you have to think, is it marck or is it lymphoid osis? So most of the time, those birds, they got the tumors, they'll die. You take that tumors you look at under the scope and you look to see the formation or how similar those lymphocytes are, the T cells. And that will tell you whether you've got Merricks or you've got lymphoid osis,
Carey: 35:13
but there's no 100% accurate way to test for this. Like I can't just walk out to on my farm and pick up a chicken and open its wing, pop some blood out from the vein that's under the wing like they do for the NPIP testing. And send that off and tell a hundred percent if a bird's got married, the bird is going to have passed and you're gonna actually have to have the liver or doing the crops or something along those lines,
Dr. Morishita: 35:45
That would be the best because they don't always circulate in the blood and they have to be a high level too.
Carey: 35:51
Okay. And if it was a high level when you're taking the blood, it would be obvious because their legs would be, like you described earlier, their eyes would be gray. They have the bumps on their skin. Something would be there at that point when it's in their blood and moving around.
Dr. Morishita: 36:12
Okay. So let's say you got a bur because now. Now when you say like in the blood, because in the blood you gotta do special things. If I'm in the blood and I look at the blood, I might not see very many of those tumor cells, the lymphocytes in the blood. But those are like special ones. You gotta stain the blood, you gotta look at under the microscope. So then we think about what are the new scientific methods that there are, there's that PCR, right? Polymerase chain reaction. So that kind of machine takes like a DNA and it's like a copy machine. It makes multiple copies. So if you got very low levels that you find that machine makes it like multiple copies, then it can be detected. So that's why people use that PCR. But again, it's a very, it's not a for the backyard chicken owner,
Carey: 37:02
so for that PCR test. If it's in, if it's in their DNA and they're immune to it, essentially it's gonna show up.
Dr. Morishita: 37:15
The PCR detects the DNA of the virus. So find it whether it's alive or a dead strain,
Carey: 37:22
okay. So even if my birds were vaccinated as chicks and a year from now somebody does a PCR test, it's gonna show positive.
Dr. Morishita: 37:35
But I don't even know if those are commercially available. That's probably in a research lab.
Carey: 37:41
Wow. Yeah
Dr. Morishita: 37:42
It's not commercially available. So for all intents purposes right now, commercially available diag diagnosis is through necropsy with the tissues.
Carey: 37:53
Gotcha. Okay. That's what I was thinking. But we have a lot of listeners Yeah. That don't know and they're very curious. And this is a very controversial topic. And we know that you know a lot about this type stuff'cause you studied it. So that's why we wanted to talk to you and find out, that the ins and outs and what was possible and what wasn't and all that good stuff.
Dr. Morishita: 38:20
May maybe in the future somebody will develop a quick test that could be done at a diagnostic lab. Nothing's impossible'cause this is a great time to be alive. Look at all the advances in medicine.
Carey: 38:31
Yeah.
Dr. Morishita: 38:32
And we could use that too. And who knows, maybe at some point they could do biopsies too and send that tissue in. And, for us that race PO poultry, because they're flock animals, you get one positive, they, you consider your whole flock positive, right? Yeah.
Jennifer: 38:51
Okay. I have a question about the vaccine itself. So when I listened to the other discussion about it, the, it was a research scientist and she was very adamant that the vaccine had to be stored and applied under very strict rules, otherwise you were just wasting your time. Would you agree with that?
Dr. Morishita: 39:15
Yes. Because remember, it's a live virus, right? We can't this has to be a mod. The Turkeys virus strain, that's a live virus. You're injecting a live virus from a Turkey into your chickens. So in commercial production, it's held like in under liquid nitrogen or, very cold environment. It's given, within no longer than. One hour or so, depending on the temperature because you wanna ensure that your birds get vaccinated and you don't wanna be vaccinating them with a, that turkeys viruses out in the, in in your air your place where you're vaccinate them they'll die over time too. So that's why you vaccinate them as soon as possible.
Jennifer: 40:02
Would you agree that a backyard person really can't vaccinate their own birds with Merricks because they don't have the tools to do it correctly?
Dr. Morishita: 40:13
You can, or you can work. Maybe you find a local veterinarian that has the supply. You have to keep that vaccine cool. Because they do sell that on some of the. Sites that sell poultry. You've seen the individual vaccine now know that for the backyard flock owner, that vaccine was developed for the commercial industry. So you're gonna see vials made for 1000 doses. And we don't, most backyard flocks do not have 1000 birds, right?
Jennifer: 40:44
So
Dr. Morishita: 40:44
one of the common things is to maybe have vaccine get togethers or whatever, and you have somebody that has a vaccine and you vaccinate all your chicks at the same time, or, those chicks are valuable. For me, I'll pay$29 to buy a vaccine because I want my birds to be protected. It all depends on human, but it has to be stored
Jennifer: 41:07
In liquid nitrogen.
Dr. Morishita: 41:09
That's to keep it cool because we have a lot of birds, so I believe that they ship it there, so as soon as they can ship it to you. From the commercial where you can buy those vaccines, you'll see them. Yeah. You have to immediately with the day you get it, and thank God. Now with the delivery service you can get when it's coming in, then you start get ready, and as soon as it comes out, then you prepare it, and then you start vaccinating the birds,
Carey: 41:38
okay, so let's just, now my son has a nitrogen tank that he can store stuff in. Because of that reason, he's gotta keep it cold.
Jennifer: 41:45
So somebody just says, oh, I just keep it in my freezer and as they hatch, I give it to him, or no?
Dr. Morishita: 41:50
No. Once you open that vial, you gotta use it.
Jennifer: 41:53
Okay. So is that doing nothing or is it doing bad? Doing What if somebody just kept it in their freezer and gave it to the chicks? Is that doing nothing at all because it is now just a moot point? Or is it actually farming? You
Dr. Morishita: 42:11
remember some frost freeze freezers do not always keep it cold. It's cold. Then it defrosts. Otherwise you got a lot of ice buildup in your freezer. Like the freezer itself it freezes and then it, the temperatures fluctuate.'cause otherwise there'll be ice buildup. That's how you can tell the freezers that don't have that frost free. So you're just wasting your right. You're gonna waste your time because that, that freezer is fluctuating. The only way they keep these vaccines is like. We have at research areas like negative 80 degrees freezers.
Jennifer: 42:46
And then
Dr. Morishita: 42:46
when we're transporting them, we're putting in a nitrogen tank, right?
Jennifer: 42:50
Okay. We see, and then you have it there,
Dr. Morishita: 42:52
but you're not gonna give the chick at nitrogen tank level temperatures. One cannot even touch the, like liquid No. That burned your skin. Yeah. So you take it out and you let it, thaw out that you're gonna get, start injecting your chicks,
Jennifer: 43:11
and then when you're done injecting your chicks, you just throw it away. The rest of it,
Dr. Morishita: 43:14
you gotta,
Carey: 43:16
because it's already thought out, so it's, you thaw it out, do it. You can't refreeze it and do it again.
Jennifer: 43:22
Okay. Got it. All right. You've, we collected some questions to ask you, but I'm looking at the list and you've answered most of'em. So the pupils, how are the pupils affected by marck?
Dr. Morishita: 43:35
Okay, so the, that Merricks disease virus is a herpes virus. It attacks a certain type of we call immune. These are immune cells of the body, and these are immune cells that, that protect the birds against disease. There are two types, A, B cell, B type A, B cell, we call it B cell lymphocyte. Those are the cell types that produce antibodies in the body. Then there other immune cell is called a t. Type T cell, a T cell type of lymphocyte. That's the one that's affected by the Marck disease virus. Okay. And so it, it mutates that T cell goes throughout the body and spreads. That's how we get the tumors. It spreads throughout the blood stream. And then that can also go to the eye. So that tumor virus invades the pupil. And that's how it changes the color.
Jennifer: 44:39
Changes the color. Does it change the shape
Dr. Morishita: 44:43
of the pupil? It might have ragged edges. A normal pupil is very nice and circular and a clean circle. If you take a look at anybody eye, even our eye. But sometimes when you, they have the invasion, sometimes you'll see little ragged edges around there. But the main thing is, the first thing you'll notice is a color. You know
Jennifer: 45:04
the gray? Oh, good to know.
Dr. Morishita: 45:07
But that's more like a chronic, the birds have survived the Merricks disease, but so they'll be alive. And you see that. So when you go through your flock, always look at your birds and see if there's different coloration. One bird with that. Maybe it had an injury. When you have multiple birds with gray eyes, you probably had merricks going through the flock. But thank goodness you only had that form and not the tumor form, because that's right. You can find dead birds, and that's why it's important that whenever you have dead birds, and we always say when you got dead birds, and if you don't mind opening up, you should open it up. Learn to look for what kind of lesions. And seeing something, if you can't take it to a vet, you can't take it to a necropsy, your state diagnostic lab. You as a poultry owner, you always wanna learn what do these diseases look like? And that tells you right away I might have this, and then you yourself can do something. Whether you got new birds or your existing birds, what do you wanna do to it?
Carey: 46:11
When I have people ask me, they're like, oh, look at this bird. It passed away. What was wrong with it? I always ask them to, I want to know what their poo looked like, because you can tell a lot by that. Very good. Yes. My next question is, can you open the bird up and look at it? Because if it smells funny, looks funny. If you see the tumors, if you see an exorbitant amount of fat or something like that, then you can tell that something was wrong with it. If you open it up. And it looks like something you would see on the aisle at Publix then. In the what? It was in a Publix, the grocery store.
Jennifer: 46:51
Oh, okay. Okay. Yeah, he's in California. They don't have Publix out there.
Carey: 46:55
If you see it, if it looks like something in the grocery, then, it could have just been a fluke. The thing had a heart attack'cause the plane flew over or something like that.
Dr. Morishita: 47:04
But
Carey: 47:04
I tell him to look at But it might
Dr. Morishita: 47:06
look like in your public store or Kroger or whatever, Safeway out here, but, or Stater Brothers. But we will not eat any bird that is dead, that is found dead. Even though it looks like the one in the store. We don't because it died of something. Because you
Carey: 47:20
don't know. But I tell people, I say, if it looks like something you would see in the store, then you're probably okay. Then it might be, if it looks bad, you need to get it checked out.
Dr. Morishita: 47:33
Okay. If it died in the store, it might have died from something, right? But it's something that we visually cannot see. So the things that we visually cannot see could be maybe a virus that doesn't cause disease like botulism. Or maybe it is something like bacterial that gone through the blood. So those are things that maybe we cannot see.
Jennifer: 47:54
But
Dr. Morishita: 47:55
Things that we visually see, then we say, oh yeah. More likely we can hint what it is. Yeah. But any dead animal or sick animal we do not eat. Do not. And I've had people say oh, after I do a necropsy, can I have that breast or whatever?'cause it looked okay.
Carey: 48:09
No you don't. You don't know.
Dr. Morishita: 48:13
No,
Carey: 48:13
that's right. I mean that you might as well go to a fast food restaurant and get something.'cause you don't know there either.
Jennifer: 48:21
Okay. So the liver of a meric bird will have white or yellow nodules on it. That makes it hard.
Dr. Morishita: 48:30
You will see that. And if you had a knife or whatever that you, and remember, if you do this on your own, this is disease, so you wanna make sure you wear gloves and clean, right? Because you don't wanna be like, oh, I just. Cut this Mars liver up and then I wipe it on my pants or something. And then you go touch your other Yeah.
Carey: 48:48
You do this and you clean up your mess and then you go take a shower.
Jennifer: 48:52
Yes.
Carey: 48:53
And put your clothes in the don't go check on the rest of your chickens or something like that before cleaning and sterilizing your hands and stuff.
Dr. Morishita: 49:01
Yeah. Yeah. Wash your hands with soap and water.
Jennifer: 49:05
Okay. I just happened to harvest or wear a
Dr. Morishita: 49:08
gloves, first of all, wear our gloves.
Jennifer: 49:09
Wear gloves. Yeah. Yeah.'cause it's gross because it's
Dr. Morishita: 49:12
common. Now you can go and buy those plastic gloves.
Jennifer: 49:15
So I harvested about 15 chickens yesterday. Two different breeds. And I always check all the insides for. Any issue because in, if I had issues in the ones I'm harvesting in several birds, then that would tell me, okay, hey, I need to look at the living birds. Then look for issues. Yeah. But all my livers, all 15 livers were that nice, dark, maroon red color lungs were pink, everything looked like it was supposed to look, and so we just motored right on through.
Carey: 49:53
You chop that up and feed it to your chicks.
Jennifer: 49:56
Lady dog was stealing out of the bucket as fast as we were
Carey: 50:01
putting that, that happens too. Yeah.
Jennifer: 50:04
So she ate good yesterday,
Dr. Morishita: 50:06
but you can check what, even the intestines if you got worms or something,
Jennifer: 50:11
yep. I, I didn't open them up yesterday, but I have opened them up before and looked and I never could find anything.
Dr. Morishita: 50:19
But I do wanna say when you give the raw meat like that to the dogs, remember? Always chickens are known to have salmonella. And so we don't wanna, it can be done, but just watch out, as a precaution too.
Jennifer: 50:33
Yeah.
Dr. Morishita: 50:33
Cooked is there. That's it. Think things like that happen. We people drink raw eggs with orange juice, those are. Those are things that we, some people do
Carey: 50:42
that, and I don't understand it.
Dr. Morishita: 50:45
They do not. Anytime we have raw food, either us or our pets, we always have the potential risk of getting bacterial diseases,
Carey: 50:55
oh yeah, definitely.
Dr. Morishita: 50:56
But some people like sunny side up eggs, that's why for people with poor immune, sys poor immune systems, you wanna cook your food well,
Jennifer: 51:04
little
Dr. Morishita: 51:05
kids or old people.
Jennifer: 51:06
Next question is, which I think we answered it, but are there any medicines available for Marx?
Dr. Morishita: 51:14
Unfortunately not. A lot of people think we can give antibiotics, but this is a virus, a viral disease. So virus is the only way to treat virus. There are antiviral in drugs. That humans have. Like when you got a cold sore, there's antiviral medications. But there is not any for poultry. And so the only way if you got like this Merrick's disease is prevention is through vaccination.
Jennifer: 51:45
There is a group on social media that swears they can cure it with some natural medicines and herbs and such. Any thoughts on that?
Dr. Morishita: 52:03
I'm not gonna say, never say never.
Jennifer: 52:06
Because,
Dr. Morishita: 52:07
How did people cure a long time in ancient times? What did people use? Natural plants, right? And herbal medicine. So I don't know what kind of herbs they are using.
Jennifer: 52:21
I'm looking really quickly because I couldn't remember what it was called,
Carey: 52:27
but I would think if that was a possibility that the commercial poultry industry, if it was a possibility for it to be done reliably and consistently, that the commercial poultry industry would be doing it like clockwork and probably have already copyrighted it.
Dr. Morishita: 52:44
They would be doing it and they wouldn't do it. Not only for Mareks, but any viral disease, right?
Jennifer: 52:50
But
Dr. Morishita: 52:51
how much is that medication gonna cost?
Jennifer: 52:54
It's Chinese skull cap.
Dr. Morishita: 52:56
Oh, yeah. I don't know. I'm not gonna expect. Okay. I don't either, But I know for other things that, you know, like in working with some people that wanna raise organic what are some herbs that are known antimicrobial? So you got like oregano, rosemary. Garlic, and we have things like probiotics,
Jennifer: 53:19
gut health is the beginning of good health. All right. I think I'm looking, I think we answered all that's,
Carey: 53:26
I was gonna say, I think we covered everything.
Dr. Morishita: 53:28
It's a tough disease, but it's so complex,
Carey: 53:32
and I really like how you explain it. And there's multiple strains of vaccines.
Dr. Morishita: 53:37
Pardon me?
Carey: 53:38
I really like how you explained it all. You did a really good job and you're very thorough.
Jennifer: 53:42
And
Carey: 53:43
you said it like everything was in a way that our listeners could understand it. They don't have to have at least a master's degree to understand the way you explained it. And so I think they'll appreciate that too, because most of our listeners are backyard poultry people. So that's what we try to, that's who we try to help out.
Dr. Morishita: 54:05
I'm here to help them if they have any questions, to the best of my ability. But that's what we know right now.
Jennifer: 54:12
We will have you back for yet another grilling on a different disease.
Carey: 54:18
Yeah. We'll collect some more questions.
Dr. Morishita: 54:21
Or eating birds that are dead.
Jennifer: 54:23
No.
Carey: 54:25
Yeah.
Dr. Morishita: 54:26
That will be a short podcast. We'll just say don't do it.
Carey: 54:29
Don't do it.
Dr. Morishita: 54:31
I had some people, if they had, they found some ostriches that were frozen. They had a cold storm and they were frozen out if they could eat it because it was cold. But it's not good. Anything dead to not eat.
Carey: 54:46
If you don't, if you don't know what caused that, don't chance it.
Jennifer: 54:51
All right. Thank you so much for being here with us again.
Dr. Morishita: 54:54
Always a pleasure. Thank you for inviting me.
Carey: 54:57
Yes, ma'am.
Jennifer: 54:59
All right. Bye bye.