Describe 'Marek's Virus- The Most Frequently asked Questions' here


Q: Isn't Marek's Virus ONLY a problem for Big commercial operations?

No. While the large commercial chicken operations got Marek's under control, Marek's was increasingly affecting the small flock owners' chickens.

Q: How did this happen?

Commercial chicken raising companies had to change their methods because they were losing so many chickens. They began practicing vaccination, " All In/All Out" with their flocks, and scrubbed and disinfected between batches of growers. Meanwhile, small flock owners like us were continuously adding chickens from everywhere, not vaccinating, and selling chickens that we didn't know carried Marek's virus, thinking that we would certainly never have that problem. In the 1980's , commercial chicken operations went from losses of 60% down to 5-10% nowadays. Meanwhile, Marek's is growing to epidemic proportions in the smaller flocks that we have. Most of us do not even know all the symptoms of Marek's in their chickens because it can mimic so many different illnesses.

Q: What are the symptoms?

Since now there are more strains of Marek's Virus, there are more symptoms. A chicken could have all , some, or no symptoms at all. Most of us know the classic symptoms, but we do not recognize all the many symptoms that Marek's can have.

- The symptoms may include: paralysis of leg or legs, may have one point forward one backward OR not.
- Cloudy eye, gray eye, or pupil not perfectly round, OR not.
-They may have small tumors all over the outer skin.
Wasting: Appearing to eat but not able to aim and pick up food, or not absorbing the nutrients and calories. Not looking sick until the end

- Paralysis of ANY nerves in the body including nerves to the lungs (causing gasping), crop ,or digestive system not moving food along, (looks like impacted crop. OR not).
- Paralysis of the legs is the easiest to recognize.
- Small tumor lumps all over the body, or not.
- Loss of control of their neck, and can't aim at food and pick it up.
- Wing paralysis, or walking with their wings, or not.
- They can look like there is nothing wrong with them with or without symptoms.
- They may have some symptoms, or, symptoms that seem to come and go. . It may be months before death.
- A necropsy can show tumors on organs. Some appear to just drop dead. It may be because they are wasting (starving) and the weight loss is covered by feathers, so it's not
seen until the last few days before they die.
*I know that's alot to read , please read it several times.

Q:How do my chickens get it?

A chicken Has to be exposed to a chicken that has it . Once they have, it's on your property, It will be there for years, or many years. There's nothing you can do. It's spread by chicken dust, dander, and saliva. You can't clean it away or cull it away. Keep a flock history. The information may help you decide when or if your flock was exposed.

Q: When will my chickens first show symptoms?

Most commonly you will see the symptoms at 6-12 weeks. However with new strains and mutation, Marek's affects chickens at any time of thier life. Most of my adults have been under 8 months old when they developed symptoms. A few were older. With older chickens, they usually waste. Chicks usually display paralysis. But this is not a rule set in stone. A Botulism paralysis usually kills a chicken within a few days. They will most likely look sick. Marek's paralysis usually does not cause death right away. Your chicken most likely not look sick at all.

Q: How do I Prevent Marek's in my flock?

You keep a closed flock. You need to start your flock by attaining day old hatchery chicks or hatching any eggs yourself. Never adding chickens that came from any other place. Not attracting wild birds. The guy at the feed store most likely does not know if they are vaccinated, but tell you that they are. Many older chickens have built up resistance, but can still carry it and infect others. Your flock may have it with no symptoms, yet, give it to unvaccinated chicks and they will die. Mareks' has no cure.

Q: Can the Vaccine or vaccinated chickens give my flock Marek's?

NOT from the VACCINE. A vaccinated chick or chicken can still be exposed to Marek's and spread it. The vaccinated chicken will have a 90-100% chance of not dying from Marek's symptoms even while carrying it.

Q: Is there life after Marek's?

Yes. Keep the flock you have.
You can buy vaccinated day old hatchery chicks, and keep them quarantined for 2+ weeks. The longer the better.
You can hatch your own flock's eggs. They may be resistant already. (I've done this twice).
You can buy fertile eggs from others , incubate them, vaccinate them day 1, and quarantine them for 2+ weeks.
You should not sell chickens from your flock. You can sell eggs. And if your chicks remain in strict quarantine, you can sell them. Remember that Marek's can be carried on you, your clothes, and your hair, and that will expose the chicks.
Please practice a moral responsibility , and not give your exposed chickens to others. Most owners who have deaths from Mareks have cried for days and lost their favorite pets or the chickens they love. And there is nothing anyone can do to save them once they are exposed and develop symptoms.

My first victim, MushMouse. The vet diagnosed him with Eastern Equine Encephalitis because he could not see any tumors in his necropsy. I didn't realize it was Marek's until over a year later when eight 6 week old chicks got paralysis one by one.

My last Victim, Clarence. I had noticed he pupil was not round one day. He wasted away over a few months.

most information supplied by
"Diseases of Poultry" , 11th edition, Editor in Chief- Y.M. Saif