Pasteurellosis, also known as bird cholera, is an infectious disease that can quickly drain the entire population. This disease is infected by all representatives of the bird family, including domestic chickens.
Features of pasteurellosis in chickens
The causative agent is pathogenic sticks - pasteurella P. Haemolytica and P. Multocida. Bacillus infected birds are slaughtered immediately and the chicken coop is disinfected. One sick chicken is enough to kill 75% of the livestock as soon as possible.
The causative agent of the disease was isolated and grown in 1880 by L. Pasteur. In honor of the scientist, the bacterium got its name - Pasteurella.
The disease affects all types of chickens - meat and egg, but young animals are especially vulnerable. Pasteurellosis is more common in countries with a temperate and warm climate, less often in the north. Cholera of birds is found both in homesteads and in large egg production farms. Even if the bird survived the disease, it is forever a source of infection - it is completely impossible to cure it.
Causes and methods of infection
The disease affects not only birds, but also mammals. Animals, especially rodents, spreading the microbe in the environment can provoke an epidemic. The disease most often affects broilers of one month old, egg fry of 2-3 months of age and laying hens at the stage of spread - at the age of 4-5 months.
Outbreaks of the disease contribute to temperature instability and high humidity. The duration of incubation is determined by the aggressiveness of the microbe, and can last from half a day to 3-5 days.
Chickens can become infected:
- through the respiratory tract due to contact with a sick bird, corpses are especially dangerous;
- penetration of bacilli through damage to the skin;
- feed or water contaminated with pasteurells;
- bites of blood-sucking insects, ticks are especially dangerous - argas and red chicken.
Pasteurella is able to dwell for a long time in natural reservoirs, in moist land, but the manure does not favor the bacillus - it is rare here. The microbe is also extremely sensitive to direct sunlight.
Once in the body of chickens, the stick multiplies rapidly. Having spread at the site of penetration, the bacilli enter the blood and lymph. The incubation period lasts several days.
Embryos in eggs can be affected by weakened pathogens that do not interfere with its growth and development. Hatching, the chick becomes a carrier of infection, and under favorable circumstances, a dormant infection will provoke an outbreak of bird cholera in the chicken coop. If the egg is affected by aggressive species of the bacillus, the embryo dies on about the 10th day. Remaining in an incubator, dead embryos can infect other eggs.
Symptoms of Cholera in Birds
The first thing that should alert is the poor appetite of chickens. At first, birds eat worse than usual. Then the condition of the hens worsens, they begin to die rapidly, one after another.
The symptomatology of pasteurellosis is vague and depends on the form of the disease, it can be:
- acute
- super-sharp;
- chronic.
An ultra-acute course is usually observed at the beginning of the spread of the disease and causes sudden death of the bird. A chicken dies literally before our eyes. The bird, which does not seem to cause disturbance, suddenly, flapping its wings, falls dead.
In order not to confuse pasteurellosis with another ailment, we recommend getting more information about other diseases of chickens here.
In acute form
The sick chicken is oppressed, she sits with a cracked tongue, her head is hidden under the wing or thrown back. Other symptoms of acute form:
- increased body temperature - up to 43-44 ° С;
- cyanotic shade of scallop and catkins;
- lack of appetite;
- ruffled feathers;
- constant thirst;
- expiration of mucus and foam from the beak;
- hoarse, labored breathing;
- diarrhea with blood.
With the development of the disease, the bird weakens, convulsions may occur. On day 2-3, the chicken dies.
In chronic form
The chronic form develops after the acute course of the disease, and is associated with the weakness of the pathogen strain. In chronic form in chickens there is:
- general weakness;
- progressive exhaustion;
- inflammation of the meninges;
- runny nose, hoarse breathing;
- swelling of the paws, scallop, jaw;
- inflammation of the eyes;
- damage to the joints of the wings and paws.
The chronic course of pasteurellosis lasts for months, the bird is depleted, its productivity decreases, but death in this state rarely occurs.
How can a disease be diagnosed?
Without laboratory tests, a definitive diagnosis cannot be made. Having noticed the symptoms characteristic of pasteurellosis, sick birds are immediately sent for slaughter. The next step is to contact the veterinarian who will take the tests, the corpses of dead birds, and send it all to the laboratory. Only after research will it be possible to establish the cause of death of chickens.
The diagnosis of "pasteurellosis" is made only on the basis of bacteriological research. Pasteurellosis is important to differentiate from bird flu, salmonellosis and Newcastle disease. Also, confirmation of the disease are autopsy data. The dead chickens have hemorrhages in the heart, spleen, and in the liver also foci of necrosis. To clarify the diagnosis, 4-5 dead birds are sent for autopsy.
A diagnosis is considered reliable if:
- a culture with properties characteristic of the pathogen was isolated from the material;
- of two animals (laboratory mice) infected with an isolated pathogen, at least one died.
Treatment methods
Pasteurellosis is not treated. All infected birds are discarded. Even if the animal can be cured, it remains the carrier of the pathogen and is able to infect healthy birds. The fight against the disease boils down to the timely slaughter of sick birds and to prevention.
Having scored all sick hens, and disposing of the carcasses, the sick individuals will be given a course of preventive therapy. They are given antibiotics for a week, for example:
- Chloramphenicol - 60-80 mg per 1 kg of live weight, 2-3 times a day (added to the feed).
- Tetracycline - 50-60 mg / 1 kg.
- Aquaprim - 1.5 ml per 1 liter of water.
For preventive treatment, it is also suitable for Spectrum B, Floron, and other drugs based on spectinomycin and lincomycin.
To find an effective drug, you need laboratory data. Based on the antibioticogram, which determines the sensitivity of the pathogen to drugs, the most effective medicine is selected.
The room in which the sick chickens were located is treated with Ecocide C or Monclavite. Lactic acid is also suitable for disinfection.
For disinfection of the house use:
- 5% solution of clarified bleach;
- 10% solution of iodine monochloride;
- 20% freshly slaked lime - surfaces are whitened three times with an interval of one hour.
On the grass mowing grass. They do not release chickens on him for two weeks - he must be exposed to the sun. Then walk sprinkled with quicklime. Plowing the ground, carefully dry all wet areas. Pasteurellosis vaccination is an exceptional measure in a small chicken farm. They resort to it if the infection cannot be eradicated by any other preventive measures.
Predictions and terms of treatment
Pasteurellosis is incurable and the prognosis for diseased birds is poor. The task of the farmer is to minimize losses by preventing the spread of infection. Only clinically healthy chickens are saved from the disease. The course of preventive treatment takes at least five days.
Are chickens contagious?
Chickens with pasteurellosis can infect healthy individuals, which is why it is so important to isolate and kill all diseased birds in time. The epidemic can also trigger carriers of the infection - chickens that survive the disease. Other types of birds, animals, and humans can become infected from chickens.
Is the disease dangerous for humans?
Pasteurellosis is dangerous not only for chickens, but also for their owners. The disease is transmitted from bird to person through direct contact. Transmission of pathogenic bacillus occurs through wounds and microcracks. Boils appear on the skin of an infected person.
Through the mucous membranes, the infection does not penetrate. Airborne infection is rare. But if this happens, a person's meninges and ears become inflamed, and osteomyelitis appears.
Precautions:
- they enter the infected house only in overalls and gloves;
- personal hygiene.
At the first alarming symptoms, it is necessary to consult a general practitioner or infectious disease specialist.
Can other animals get infected?
Pasteurellosis is dangerous not only for chickens, but also for other birds - geese, turkey ducks, quails. Farm animals like pigs, cows, goats, etc. are also sick. It is also found in cats and dogs. Any animal can become infected with it - through direct contact, through drinking, food, bites, scratches. The source of infection is sick animals and carriers of infection. The latter include mice, rats and guinea pigs - they can live and spread bacilli for years.
Is it possible to eat meat of a bird suffering from pasteurellosis?
Meat slaughtered due to pasteurellosis of chickens can be eaten. Chicken farmers are interested in profit. If all birds slaughtered due to the outbreak of the disease had to be disposed of, they would have suffered enormous losses. Fortunately for poultry farmers, the meat of chickens suffering from pasteurellosis becomes safe after heat treatment. But the pest controllers have their own opinion on this matter - they believe that all infected chickens, alive or slaughtered, should be destroyed.
Prevention
Pasteurellosis prevention measures:
- compliance with sanitation and hygiene;
- timely isolation and disposal of carriers of infection;
- good nutrition - vitamin supplements are included in the diet;
- mowing and plowing overgrown paddocks;
- vaccination.
Chickens are vaccinated with live or inactivated vaccines. A living drug has a residual effect - complications are not excluded. Therefore, chickens are usually vaccinated with non-living vaccines.
Vaccines are not used for treatment. Only clinically healthy chickens are vaccinated. The minimum age of birds for vaccination is 1 month. For 6-8 months, the vaccinated chicken maintains immunity, and then re-vaccination is required.
If there is an outbreak of pasteurellosis on the farm, inanimate vaccines are combined with antibiotic therapy. Vaccination can be done before, after or in parallel with a 5-day course of antibacterial therapy.
Pasteurellosis is a real disaster for any chicken coop. It is much easier to prevent the disease than to deal with its consequences. If chickens get bird cholera, the population will inevitably decline. It is important to notice an outbreak of pasteurellosis in time in order to take preventive measures.
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Russia. City Novosibirsk
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