How to Prevent Marek’s Disease in Chickens
by Alexa Lehr | The Pioneer Chicks | November 21, 2023
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Marek’s disease is a prevalent virus that commonly infects young and growing chicks but can also infect mature birds as well. This complex virus impairs a chicken’s immune system, making it more susceptible to the virus and other diseases, and it switches off a chicken’s tumor-blocking genes. The best way to keep your flock safe from Marek’s disease is to know how to prevent the virus from becoming chronically infective in your flock. This guide on how to prevent Marek’s disease in chickens will walk you through some simple measures you can take to help keep your homestead flock healthy and safe!

Is Marek’s Disease Preventable?

The Marek’s disease virus is a complex virus. Despite being one of the most widely studied chicken diseases, it is still not completely understood. There is no cure for Marek’s disease and it is so widespread that most experts believe that you can safely assume your flock has been exposed to the virus.

But don’t panic! Just because Mareks disease is practically unavoidable doesn’t mean it’s not preventable. However, since the virus is so prevalent, the best prevention your flock can have is immunity to the virus which is built through a strong immune system.

A strong immune system means a chicken is able to fight the virus when exposed to it. This leads to immunity which prevents the virus from becoming infective. A strong immune system is the foundation to Marek’s disease prevention. The following 4 prevention tips will help you build that strong immune system foundation in your brood or flock. 

You can learn more about Marek’s disease in my post on What is Marek’s Disease in Chickens?.

#1. Brooding for Marek’s Immunity

Like many poultry diseases, Marek’s disease is most fatal for young and growing chicks. As chicks grow and mature, they are also gradually building up natural immunity to the viruses, parasites, and bacteria in their environment. The younger a chicken is, the more susceptible it is to disease since it’s immune system won’t be as strong as an adult chicken. However, you can brood chicks in such a way as to encourage good immunity.

Reduce Exposure:

If you have a flock of adult chickens, more than likely the Marek’s virus is present in the environment. When raising chicks hatched from an incubator, brood them away from the adult chickens. This will minimize the quantity of infectants the chicks are exposed to while they are building immunity.

Chicks hatched and brooded by a healthy mother hen can be exposed to some of her anti-bodies through her droppings. This helps stimulate their immune systems to start developing immunity to the Marek’s virus immediately. However, chicks hatched from an incubator and raised in a brooder will not have that luxury.

Instead, the chicks should be kept completely isolated from adult birds until they are 5 months of age. By this time their immune system should have developed natural immunity that will help them overcome the Marek’s virus as adults.

Now, I know on the homestead, keeping your young brood completely isolated from adult birds may not be practical. That’s when helping your chicks develop a strong immune system comes into play!

Immune System Support:

While the immune system will naturally become stronger as a chick grows, there are some things you can do help that support strong immune system development. Using natural supplements, herbs, and keeping a clean brooder can all help support a healthy immune system.

I’ll dive into some more aspects of supporting the immune system later. For now, check out these resources for raising a healthy brood of chicks:

• 8 Ways to Keep Your Chicks Healthy
• 7 Herbs for Baby Chicks on the Homestead
• 10 Helpful Facts for Raising Chicks
• How to Tell if a Chick is Healthy

Biosecurity Practices:

You should also be brooding your chicks using good biosecurity practices. Good biosecurity reduces the exposure your chicks will have to Marek’s disease and other harmful pathogens. Here are some ways you can practice good biosecurity when raising chicks on the homestead:

• care for young chicks before tending to an adult flock
• make sure the brooder litter stays clean and dry
• clean and sanitize the brooder between broods of chicks
• keep the feeder and water clean and free of droppings
• ensure there is good ventilation in the brooder

#2. Breed for Resistance

Good breeding is the foundation for a healthy flock. Disease hardiness and resistance can be hereditary. A good breeding flock should be healthy and free from parasites, chronic diseases, and any other health issues. Breeding birds with strong immune systems will result in healthier chicks who can also develop strong immune systems.

When buying chicks, purchase from reputable sources who know the breeding history of their flock. While you can certainly go to the farm store and pick out some chicks for your homestead flock, buying from a responsible breeder will get you healthier birds in the long run.

Chickens can also be bred for resistance to Marek’s disease. Some chickens carry the resistance gene, B21. This gene can only be detected through blood testing. Essentially, the resistance gene prevents the virus from creating tumors or compromising the immune system. Fayoumi chickens are a chicken breed with a very strong constitution that makes them genetically more resistant to many poultry disease, including Marek’s disease.

If the resistance gene is present in a bloodline, you can selectively breed individual birds to make the gene more prevalent in your strain of chickens.

#4. Support the Immune System

The immune system is a chicken’s defense against disease and parasites. A strong immune system will not only help a chicken fight the Marek’s virus, but it will also help the chicken fight other disease causing pathogens as well.

Just because chicks (or chickens) have built immunity to one form of Mareks disease doesn’t mean they are immune to all forms of the virus. That’s why a strong immune system is always important. If the immune system is strong, it will fight new forms of the virus that the bird may not have built up immunity to. 

You can support a strong immune system in your brood or flock with these tips: 

Herbs

Herbs are a great holistic asset to have on the homestead, so it should be of no surprise that they can help support a strong immune system in young chicks and in mature chickens. Certain herbs specifically boost the immune system. Other herbs are rich in antioxidants or work as natural antibiotics, both of which can help the immune system stay in strong working condition.

Here are some beneficial herbs to offer that can help boost the immune system to prevent Marek’s disease:

• Immune Support– bay leaves, echinacea, astragalus, turmeric
• Rich in Antioxidants– dandelion greens, marigold, sage, tarragon, thyme
• Natural Antibiotics– oregano, thyme, nasturtium

You can supply these herbs free-choice, use them as fermented feed or treat toppers, or add them to your flock’s drinking water. Herbs in powder form (like turmeric or astragalus), are best sprinkled over fermented feed or treats.

These herbs are best used on a varied basis. Offer one herb for a little while, then switch to a different herb so that a chicken’s body doesn’t get used to receiving one herb all the time. In general, it’s best to use a single herb for 7-10 days, then take a break or switch to a different herb. Alternatively, use an herb on a once-a-week basis rather than continually every day.

All of these herbs can help boost the immune system on a regular basis and they can provide immune support when the immune system might be taxed or stressed. You can give these herbs to both young chicks and adult chickens. Young chicks should be given smaller amounts of an herb compared to an adult chicken.

Natural Supplements

Other natural supplements can be used in addition to herbs for supporting a strong immune system. Like herbs, these natural supplements are best used on a varied or as-needed basis. Offer these supplements during times when a chicken might be stressed or more susceptible to illness. I’ll discuss some situations that might cause immune stress in a minute.

But for now, consider stocking these natural supplements in your poultry first aid kit:

• Raw Garlic– crush 3-4 cloves into 1 gallon of water, replace with fresh water after 48 hours
• Probiotics– follow the directions on a probiotic formula specifically formulated for poultry
  • Fermented Feed– fermenting chicken feed provides a natural source of probiotics
• Raw Honey– dissolve 1 T. of raw honey into 1 c. of water, administer individually or supply free-choice
• Elderberry Syrup– use an all-natural recipe and administer individually

Immune Stress Prevention

When a chicken is experiencing stress, one of the first places it diverts energy from is the immune system. Thus, stress can cause a chicken’s immune system to become suppressed. Without energy to work properly, the immune system won’t be able to fight disease and help a chicken build immunity.

To help a chicken’s immune system stay in healthy, working condition you should prevent stressors that can cause immune suppression. Here are some factors that can cause immune system suppression:

• other diseases, especially chronic diseases
• parasites, both internal and external
• cold stress or heat stress
• overcrowding
• boredom
• predator attacks
• dirty living conditions

By preventing these factors, you will reduce the affects they have on a chicken’s immune system. If some of these factors are unavoidable (like cold stress during a sudden cold snap), offer immune boosting herbs and supplements to support the immune system during the time of stress.

#4. Raise Turkeys

Lastly, you can raise turkeys to help your chickens develop immunity to Marek’s disease! Turkeys carry a non-tumor forming virus that is similar to the Marek’s virus that infects chickens. This related virus is often used in Marek’s disease vaccines. However, turkeys can also naturally shed the virus and thus expose chickens to the virus. The turkey virus is not harmful to chickens, and instead, it can naturally help chickens build immunity to Marek’s disease.

When chicks or chickens are ‘infected’ by the harmless turkey virus, the virus works to prevent the Marek’s virus from forming tumors. Chicks and chickens can be exposed to the turkey virus when they are raised with turkeys or are exposed to the turkey’s droppings.

While it is not advisable to raise both chicks and young turkeys (poults) in the same brooder, you can still expose young chicks to the turkey virus by placing some turkey poop in the brooder. For adult birds, keeping chickens and turkeys together can expose the chickens to the harmless and beneficial turkey virus.

Even though the Marek’s virus is a prevalent and mysterious chicken disease, you can still take preventative measures to protect your homestead flock! A strong immune system is the foundation for preventing Marek’s disease. Building a strong immune system starts as soon as a chick hatches. Using herbs and natural supplements can help support the immune system, but you should also use good brooding and management practices to keep your chicks and chickens healthy. With a strong immune system, your flock will be able to fight the virus and prevent it from becoming infective in your homestead flock!

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