Content
Raising chickens is an interesting and profitable activity. But farmers often face the problem of poultry diseases. The disease of any animal is unpleasant and causes material damage to the owners of even a small poultry farm.
Chickens suffer from various diseases. Some of them are associated with mechanical damage, improper maintenance, care and feeding. Others are caused by infections that can destroy the entire chicken population in an instant. Marek's disease in chickens has its own characteristics and control measures. We will talk about them now.
Historical reference
This disease of chickens has been around for over a century. It was described by a scientist from Hungary at the beginning of the 20th century, and he even came up with a name - chicken polyneuritis. A little later, already in 26, polyneuritis was identified by the Americans A.M. Pappenheimer, L.P. Dan and M.D. Zeidlin in the nervous system, eyes and internal organs of chickens.
This infection has been proven to be contagious, causing damage chicken diseases colossal, since it is impossible to completely cure a bird. Over the course of a hundred years, the disease spread across all continents. Soviet scientists have also studied the infection since 1930, but have not come to a consensus on the issue of treatment.
General information about the disease
The disease virus infects the cells of the chicken’s body, from which point it becomes a dangerous carrier of infection. Moreover, infection occurs quickly if the sick bird is not removed from the rest of the chicken flock.
The dangerous Marek's disease virus is not only found inside the chicken's body. It can be released into the surrounding space, end up in food, on feathers, in dust and bedding. In a word, everything that a sick chicken comes near becomes infected.
The Marek's disease virus survives at temperatures up to +20 degrees and remains active for a long time. Temperatures up to +4 degrees allow it to live for several years. But at high air humidity the virus dies.
How do domestic chickens become infected? DNA containing a virus called herpesvirus enters the chicken's body. It blocks the process of antibody formation and exhibits interferonic activity from the very first minutes.
Incubation period of the disease
It is simply impossible to determine that a chicken has Marek's disease at first, since no clearly defined specific signs are observed. Although experienced poultry farmers who constantly monitor the condition of their birds may notice some external changes:
- a chicken's comb turns pale during illness;
- a gait unusual for chickens appears;
- chickens take unnatural poses;
- due to weakening and exhaustion, motor activity decreases.
The incubation period is very long - 2-15 weeks.At the end of it, the symptoms of Marek's disease in chickens become clear.
Forms of the disease
This infection has three forms, each of which has its own characteristics:
- With neural damage, the chicken’s peripheral nervous system is damaged, and the result, as a rule, is paresis and paralysis.
- The ocular or ocular form leads to poor vision. In some cases, the chicken goes blind. The mortality rate of chickens from the eye form is up to 30%.
- With visceral tumors form on the internal organs.
In addition, the disease in chickens can occur in acute and classic forms.
How to recognize Marek's disease
As we noted, the incubation period is extended. In older chickens with weakened immune systems, symptoms of Marek's disease appear more quickly.
Signs of the disease
Acute form
The disease in an acute form, similar to leukemia, is most often characteristic of young animals from one to five months. Since the infection is highly virulent, Marek's disease can affect all chickens within one to two weeks. Chickens suffer from paresis and paralysis. One of the symptoms is paralysis, clearly visible in the photo.
Symptoms:
- digestion is disrupted;
- chickens eat poorly, which causes them to lose weight and become weak;
- tumors form on parenchymal organs;
- The egg production of chickens is almost non-existent.
As a rule, the chickens die after a short period of time.
Classic shape
This form of Marek's disease is less aggressive; with timely measures, 70% of the herd can be saved. The lesion affects the nervous system or eyes of chickens.
What are the manifestations:
- the chicken begins to limp;
- her tail and wings sag, her neck may curl;
- Paralysis is also observed, but it is short-lived.
If there are signs of disease on the farm, special attention should be paid to the eyes:
- if the disease affects the eyes, vision is impaired;
- the chicken's iris changes color;
- the pupil becomes unnatural: pear-shaped or another shape, look at the photo below;
- Chickens do not react to light.
In some cases, complete blindness occurs. If the disease affects the eyes, the poultry will not live long.
Treatment
Poultry farmers are not always able to recognize the disease, so specialists must be involved to establish a diagnosis.
If the disease of chickens is noticed and detected at an early stage, they can be pierced with antibiotics and antiviral drugs. When paralysis occurs, no treatment will help. You just have to kill the sick chicken and burn it.
Poultry farmers have the only opportunity to protect their chickens - to vaccinate them in a timely manner.
Features of vaccination
Vaccination of chickens is the surest way to a healthy poultry population. It can be done in different ways:
- One of them can be carried out with special equipment while the chicken is still in the egg. It is clear that such vaccination is unacceptable for a homestead. But poultry farmers should know about it. After all, chickens are often bought from poultry farms. What is the essence of the method? The graft is placed directly into the egg on the 18th day of incubation. This is the best protection against Marek's disease. Therefore, when purchasing chicks, you need to ask whether such vaccination has been carried out.
- At home, newly hatched chickens need to be vaccinated in the first 24 hours of their life.The vaccine can be purchased in almost all specialized stores or veterinary pharmacies. The vaccine is sold together with saline solution. Before vaccinating chickens, read the instructions.
Why should young animals be vaccinated from the first days of life? You probably remember that the virus can be transmitted through the air and carried on clothing. And in small farms, as a rule, chickens are raised by chickens. No one can guarantee that she is not a carrier of the infection.
If an effective vaccine is administered to hens while they are laying eggs, the antibodies produced in the mother's body will be transferred to the chicks. They will be protected for 3 weeks. Vaccination is carried out after the protective period has expired. Then no treatment will be required.
Vaccination of newborn chickens:
Biosecurity
Biosecurity or preventive measures will help maintain healthy chickens, then the manifestation of Marek’s disease will be out of the question. Firstly, it is necessary to create optimal conditions for maintenance. Secondly, chickens need to be given maximum attention.
Now we recommend that you get acquainted with the rules that will help save your small poultry farm from Marek’s disease and receive high-quality and healthy products.
Rules for safe poultry farming:
- Compliance with veterinary and sanitary standards: included in chicken coop wear special shoes and clothing, change them when leaving, and wash your hands thoroughly.
- Maintaining cleanliness in the chicken coop, carrying out preventive disinfections. Feathers must be collected and burned.
- Cleaning chicken feathers from dandruff using special means.
- Keeping young and adult chickens in different rooms.
- Timely vaccination of poultry.
- Tracking sick chickens, culling and destruction (burning) to prevent mass infection of other poultry.
Conclusion
Despite the fact that Marek's disease is not such a rare disease, you can ensure that it does not exist in your yard. We talked about how to achieve this in our article. If you follow all the rules and regulations, your chickens will be healthy. You will receive not only tasty and healthy eggs and dietary meat, but also an annual litter of strong chickens.
