Avian aspergillosis: description, symptoms, treatment and prevention

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Aspergillosis is an infectious disease caused by the fungus Aspergillius. This disease affects not only birds, but also farm animals. To date, two forms of this disease are known - acute and chronic. After reading this article, you will understand whether it is possible to eat the meat of birds with aspergillosis.

Brief historical background

For the first time, mold fungi were found in the bronchi and lungs of birds as early as 1815. They were found by the German scientist A. Meyer. Forty years later, in 1855, they were identified by another scientist, Fresenius, who was studying the respiratory system of birds. It was he who gave the name to this disease.

Over time, it was found that this infection affects not only birds, but also many mammals. This is one of the most common mold mycoses officially registered in most of the world's countries. The disease is taking a huge economic toll on poultry farms as more people die from ithalf of the young livestock.

How does infection happen?

Most often, avian aspergillosis occurs due to the fungus Aspergillus flavus, but it also happens that it is provoked by other pathogenic microorganisms. It has been established that the causative agent of the disease is found in the reproductive material, fodder grain and soil. Fungi are resistant to elevated temperatures, so they actively multiply and develop even at 45 degrees. Some varieties of Aspergillus are not afraid of chemicals and disinfectants.

In most cases, infection occurs by aerogenic means. As a rule, individual individuals are infected, but sometimes the disease becomes widespread. Outbreaks of aspergillosis occur only in the presence of a sufficient number of pathogenic microorganisms. The source of infection most often becomes infected litter in the chicken coop.

Another cause is believed to be a violation of resistance due to the use of immunosuppressive drugs, improper diet or stress. Also, infection can occur during contact with infected individuals.

How does Aspergillosis progress?

Symptoms in birds vary with age. The disease can occur in acute or chronic form. The first is usually found in chickens under thirty days of age. The first symptoms appear three days after infection. Sometimes this period is reduced to one dayor increases to ten.

Chickens infected with fungal spores show stunted growth, shortness of breath and rapid breathing. They become lethargic. Avian aspergillosis can be recognized by one characteristic feature. Infected individuals begin to stretch their necks and swallow air. In an acute course, at least half of the infected young animals die. In some cases, they develop diarrhea, cough, and discharge from the eyes.

Aspergillosis symptoms in adults

Laying hens usually get chronic. The course of the disease is somewhat different from that observed in young livestock. Adult birds have:

• Flowing from the nose and eyes.
• Diarrhea.
• Difficulty breathing, shortness of breath and cough.
• Embryo death.
• Exhaustion.

Chickens stop laying. Some individuals are paralyzed, leading to death.

Avian aspergillosis: diagnosis

An experienced farmer can easily recognize this disease. To confirm the diagnosis, the corpses of dead birds are sent for autopsy. As a rule, whole colonies of microorganisms are found in their air sacs and lungs, in appearance resembling small yellowish grains crumbling under scissors. In the process of opening the hatching eggs of laying hens, dark green or black spots are clearly visible on their shell membranes.

Further obtained biomaterial collected using certainantiseptics, sent for laboratory testing. Specialists carry out sowing on special media. As a rule, agar based on Czapek's solution or dextrose is used for these purposes. Since it takes at least ten days to get the final result, treatment is started before the final diagnosis is made. The rather low performance of serological tests is due to the uncharacteristic nature of the antigens.

Healing Methods

Farmers who realize that their livestock has been diagnosed with avian aspergillosis, the treatment of which is to destroy the pathogen, should immediately begin to act. These microorganisms are sensitive to iodine-containing drugs and antifungal spectrum antibiotics. This feature must be used not only for therapeutic, but also for preventive purposes.

At the slightest suspicion of avian aspergillosis, treatment of broilers should begin with mandatory aerosol treatment of livestock. It is advisable to do this indoors. Sick individuals are given potassium iodide at the rate of 0.15 milligrams per head. Copper sulphate, diluted in a ratio of 1:2000, has proven itself quite well. The bird needs to drink this liquid for five days.

Additionally, you can give chickens antibiotics of the antifungal spectrum. It should be noted that the effectiveness of such drugs usually does not justify their cost. You can use medicines such as "Intraconazole" or "Mycoplazol". Antibiotics desirableselect individually.

Preparations suitable for aerosol treatment

In the room where individuals diagnosed with avian aspergillosis live, it is necessary to spray special agents that prevent the further spread of pathogens. For these purposes, iodine monochloride can be used. In this case, processing is carried out by wire or sublimation with aluminum powder. For one cubic meter of poultry house volume, 0.5 milliliters of the drug is needed. In case of poor sealing of the room, it is advisable to double the dosage. Half an hour after treatment, the chicken coop is thoroughly ventilated.

Chloroturpentine has proven itself well. Processing is carried out by the sublimation method. One cubic meter will require 0.2 milliliters of turpentine and bleach. You can also spray iodotriethylene glycol indoors. Such processing is carried out for five days in a row. After a 48-hour break, it must be repeated.

Preventive measures

A disease as complex and dangerous as avian aspergillosis is more difficult to treat than to prevent. For prevention purposes, it is necessary to carry out daily cleaning and disinfection of containers intended for drinking water. In order to avoid the possible spread of infection, it is recommended to water the birds with a solution of copper sulfate prepared in a ratio of 1:2000. But this method cannot be considered a panacea, since it does not guarantee complete protection of the livestock from the harmful effects of pathogens. Experts do not advise too often to resort tothis technique.

For prevention purposes, a special vaccine can be used. To reduce the number of microorganisms, it is necessary to systematically ventilate the house. It is desirable that the room intended for keeping chickens has natural ventilation.

The basis of the diet of poultry should be high-quality feed prepared in full accordance with generally accepted standards. For their storage, it is recommended to use dry closed rooms. To avoid the rapid development of microorganisms that provoke aspergillosis in birds, you should get rid of dampness in the chicken coop. Uneaten food is recommended to be disposed of by incineration.

Outbreak activities

If, despite all the preventive measures taken, infection of the livestock has occurred in the poultry farm, it is necessary to carry out a whole range of actions aimed at stopping the disease.

First of all, you need to identify all sources of infection and exclude all questionable food from the bird's diet. Individuals that have already begun paralysis should definitely be destroyed. After that, it is necessary to disinfect the house in the presence of feathered inhabitants. You also need to promptly get rid of all bedding and litter. Such a competent approach will significantly reduce the mortality of livestock or avoid initiation altogether.