Aspergillosis In Birds: Causes | Symptoms | Treatment | Diagnosis & Prevention

Aspergillosis is one of the most commonly occurring fungal infections found in birds, in particular, turkeys, ducks, parrots, penguins, chickens, waterfowls, etc.

The young birds are majorly affected by the disease, though older ones can also be infected if they lack immunity. 

What is aspergillosis in birds?

Aspergillosis is a non-contagious fungal infection that commonly affects a wide range of domestic and wild birds by causing respiratory health problems or more distributed systemic diseases in them. 

Commonly referred to as fungal pneumonia, mycotic infection, or brooders pneumonia, Aspergillosis is caused by the fungus Aspergillus which exists in varied indoor and outdoor environments or organic substrates. 

In this fungal infection, the tissues in the body gradually damage over a span of a few weeks to months, leading to a state when an organ or system is severely endangered. 

Mostly, the respiratory system is majorly damaged as the disease causes both lower (air sacs and lungs) and upper (eye, sinuses, nose, and trachea) respiratory problems.

Aspergillosis in birds may occur in two forms:

Acute Aspergillosis

In the acute presentation of aspergillosis, the fungus typically impacts the voice box, air sacs, and trachea. It mostly occurs from a profuse concentration of fungal spores.

Chronic Aspergillosis 

Chronic aspergillosis in birds is more common and severe. The primary site of infection is the lungs. The white nodules grow and tear away the tissue, with an overwhelming amount of spores entering the bloodstream.

The spores then make their way inside the bird’s body and impact multiple organs and even the eggs, causing the death of embryos. 

How do birds become infected with aspergillosis? ( causes )

The inhalation of the spores of the fungi Aspergillus leads to the infection of Aspergillosis in the birds. The fungus subsists in the environment in the form of microscopic spores that are found almost everywhere. 

Aspergillus fumigatus, Aspergillus flavus, and Aspergillus niger are the most common causative species that grow easily in environments with warmth and moisture. 

The chances of the inhalation of the spores are excessive because they have the ability to proliferate in a large number of environments and resist disinfection.

The reason behind this is their great thermal tolerance that makes the fungi ubiquitous organisms. 

But just inhaling would not result in aspergillosis, various other reasons can predispose birds to become infected with the disease such as:

  • The birds with lower immunity, compromised due to malnutrition or other health problems, are more prone. 
  • Long-term antibiotic use, steroid use, excessive stress, poor hygiene, viral infections, or other severe infections can lead to immunosuppression which can further cause chronic aspergillosis. 
  • Injury to birds’ respiratory systems can make them vulnerable to becoming infected.
  • Birds that feed on all-seed diets become infected easily as the seeds lack vitamin A, prominent nutrition for birds’ healthy immune systems and respiratory tracts. 

Some other risk factors are:

  • Wild-caught animal
  • Physical exertion (eg, migration)
  • Trauma
  • Genetics (eg, inbreeding)
  • Toxicosis

Healthy birds can also have the risk of developing infection but only if the birds are exposed to a large number of spores. Usually, the disease occurs in young birds. 

Aspergillosis in birds symptoms:

What are the first signs of Aspergillosis?

Birds with aspergillosis do not show very specific signs during the early phase of their infection. But ultimately,  the birds may show signs of the disease such as depression, inappetence, tail throbbing, reluctance to fly, etc.  

The symptoms of acute and chronic aspergillosis are not very similar. Birds with an acute form of the disease show the signs early as compared with the birds having chronic form. Thus, it becomes quite difficult to acknowledge the chronic form of the disease in birds.

Here are some of the common symptoms of acute aspergillosis in birds:

  • Weakness
  • Silent gasping
  • Increased thirst
  • Frequent Urinating
  • Drowsiness
  • Bluish mucous membranes 
  • Eye swelling
  • Torticollis 

The symptoms of the chronic form of aspergillosis are:

  • Trouble breathing
  • Change in the bird’s voice
  • Opacity
  • Eye discharge
  • Neurological dysfunction
  • Lethargy
  • Diarrhea

How do you test for bird aspergillosis?

Many different tests can be done to confirm aspergillosis in birds. A single test may not provide absolute confirmation but when multiple tests are done together, they provide more clarity.

Here are a few tests that can be employed for bird aspergillosis:

1. X- rays

X-rays are the most common tests that are done to view lesions.

At the early stage of infection, they may show subtle lesions. But later in the disease, the x-ray may show changes like thickening of air sacs, pneumonia, or breakage of a bone.

2. Serology (antibody)

The tests are available but they cannot be trusted completely as there are chances that they can have false negative or positive results.

This is because most infected birds do not have a healthy immune system, which is necessary to mount antibody response, thus resulting in false-negative results.

Whereas, false-positive results occur as well because many healthy birds may have antibodies as the fungi are commonly present in the environment.   

3. Tracheal Wash 

If the bird’s trachea is affected by aspergillosis, the tracheal wash may help in knowing the presence of aspergillus organisms in it. However, small spores can be present in healthy birds as well.

4. Laparoscopy

It is the most accurate technique that provides a complete view of the bird’s trachea, air sacs, sinuses, and lungs. The technique involves passing a fiber-optic endoscope surgically into the bird’s airways. 

Can you cure aspergillosis in birds?

Aspergillosis is an extremely challenging disease to cure in birds.

However, if the diagnosis of the disease occurs at the right time, the right treatment can be provided to birds, leading to the curing of the disease.

A strong immune system is the most important requirement to eliminate the disease completely. The treatment often takes a long time.

How do you treat Aspergillus in birds? 

Aspergillosis in birds is treated by providing antifungal medications to infected birds. The drugs can be given orally, topically, or by directly injecting into the bloodstream.

The treatment may also include surgery for the removal of lesions.

The common antifungal drugs include fluconazole, itraconazole, amphotericin B, and clotrimazole. There has been no vaccine developed yet for immunization from aspergillosis in birds.

Other than clinical treatments, supportive care may also help in making the treatment more effective. It includes:

  • Hospitalisation
  • Supply of Warmth
  • Oxygen therapy
  • Force-feeding
  • Treatment of other existing diseases

How to prevent aspergillosis in birds?

Controlling the factors that support the growth of the spores of Aspergillus can help in preventing the infection in birds. 

Here are some of the common prevention practices:

  • Keep birds’ surroundings clean and disinfected. Make sure to practice proper sanitation regularly to avoid any contamination.
  • Store feed in clean and dry containers.
  • Regularly replace bedding to eliminate any sort of contamination.
  • Store and keep the eggs in a moisture-free and clean space. 
  • Provide fresh, nutritious food to increase birds’ immunity.
  • Ensure good ventilation in birds’ in hatcheries and poultry farms.

What happens if aspergillosis is untreated?

Aspergillosis can lead to chronic health diseases, organ failures, and even death, if not treated in time. The fungal infection can affect not just the respiratory system, but also other organs and systems of the bird’s body.

The acute form of aspergillosis is severe and requires immediate treatment. The lack of treatment results in congestion of air sacs with white mucus and severe growth of nodules.

Chronic aspergillosis damages the birds’ lungs gradually. If not treated, it can affect the central nervous system, leading to paralysis, loss of coordination, and tremors in birds.

Wrapping up: 

Aspergillosis is a fungal infection that you would never want your birds to get infected with as it can affect them severely if not acknowledged and treated in time.

So, the best way to dodge the disease is by implementing prevention practices.