Menu Close

What Causes Marek’s Disease in Chickens

what causes marek's disease in chickens

Marek’s disease or also known as “chicken paralysis” is a highly contagious viral neoplastic disease among birds. This disease tends to take caregivers by surprise so in this post you will learn a little more about Marek’s disease.

WHAT IS MAREK’S DISEASE?

Let’s start by explaining a little more about what this disease is. Marek’s disease, also known as “chicken paralysis”, is a viral neoplastic disease, characterized by the presence of T-cell lymphomas infiltrating the organs and tissues of birds.

WHAT CAUSES MAREK’S DISEASE IN CHICKENS

This is caused by a herpes virus called Alphaherpesvirinae. This disease is highly contagious, can even persist in the environment for several years and has a high mortality rate, usually affecting more hens than chickens and rarely affecting turkeys.

The virus can vary from non-pathogenic (not causing disease) to highly pathogenic (causing disease and death), and this depends on the strain of Marek’s disease contracted.

SYMPTOMS OF MAREK’S DISEASE IN CHICKENS

Many symptoms are similar to other diseases so it may be a little difficult to make an early diagnosis. But their symptoms also depend on the severity of the disease.

It rarely happens that some animals die without presenting the characteristic symptoms of the disease but the usual symptoms affect the nervous system, eyes, skin and other organ systems.

Neuronal symptoms of Marek’s in chickens: these symptoms are the most common in progressive paralysis diseases.

  • Stretched legs. Due to inflammation of the sciatic nerve.
  • Flaccid paralysis of the neck.
  • Turning of the head to one side or backwards
  • Weight loss.
  • Difficulty in breathing.
  • Lack of appetite.

Eyesight:

  • Hen’s eye becomes pale and gray.
  • Unequal Iris.
  • It can develop blindness.

Cutaneous:

  • Appearance of excessively elongated and reddened feather follicles
  • Appearance of white bumps on the skin that lead to the formation of brown scabs.

Visceral:

  • Lymphomas may appear in different internal organs such as the heart, liver, lungs, ovaries, etc.

Many of these symptoms could be signs that your baby chick is dying.

HOW TO PREVENT MARECK’S DISEASE IN CHICKENS

The best way to protect your animals from this disease is first of all, to prevent it.

HOW DOES MAREK’S DISEASE SPREAD AMONG CHICKENS

The virus spreads horizontally, that means, from hen to hen (not from the hen to egg) mainly by direct contact between birds and by contact between dust and infected follicles and scales. Therefore, it is recommended that you make sure your hens have enough space.

There are biosecurity standards that farms must follow to control and prevent the spread of Marek’s disease in birds, but when it does appear, there is no medication that can reverse it.

For this reason the management of the birds, biosecurity and vaccination is very important when trying to avoid the disease.

Many keepers are lucky enough to never see this disease in their animals, despite how highly contagious it can be. To find out if it is common in your area, call your local extension office, they will be able to provide you with this information.

We hope that this post will be useful to you in order to be alert and to be able to prevent this disease that unfortunately is more common and contagious than it seems.

cheap supplies for livestock