Fungal

This disease is caused in pigeons by the fungus Aspergillus fumigatus and in rare cases by Aspergillus flavus and Aspergillus niger.
The fungus spreads by forming threads and can spread over a surface. Multiplication takes place by forming spores. These are tiny particles that spread through the air. It is a fungus that occurs almost everywhere in nature. Birds can become infected by breathing in these spores.

Condition

Whether an infection with the spores causes disease is largely due to the condition of the pigeon. A healthy pigeon that gets a good feed without deficiencies, will, in most cases, be able to tackle the inhaled spores itself and no disease will occur. Vitamin A deficiencies often play an important role in the development of fungal infections. In cases of infection with large numbers of spores, a healthy bird can also develop the disease.

If Aspergillus is not eliminated by the body itself, it will multiply and cause illness. The biggest problems with pigeons are often seen in the airways.

Acute or chronic

Aspergillus can have an acute or chronic course. With an acute form, the fungal spores attack different places and cause a large infection throughout the body. In addition to the airways, the liver and kidneys can also be affected. The pigeon will soon become ill, will not want to eat and will have difficulty breathing. They often drink a lot and droppings may be green coloured. They can even die suddenly without obvious symptoms.

The chronic form is more common. The fungi grow slowly, from one or more places in the body (often starting in the airways). They form plaques and granulomas (lumpy masses) of mould.

The fungus can attack at different places in the body.  For example, fungal plaques can be in the nose or in the throat slit, and they often settle in the air pockets. Here they cover the wall and can even close the connection to the lungs. Spores that are formed spread slowly through the body. This can be a very insidious process. The birds are not acutely ill, but do lose condition, can be a bit slow and sleep a bit more. Shortness of breath is often present, especially after exertion.

Fungal disease

The disease is more common in parrot varieties than in our racing pigeons, where this fungal disease is rather rare. However, I would like to write an article about it, because the symptoms are often reminiscent of other diseases.

Due to the tightness of the chest, we often first think of the ornithosis complex of the deeper airways, such as lungs and air pockets! If the usual antibiotic treatment(s) don’t work quickly, you have to look further to arrive at the correct diagnosis. In our pigeon clinic in Colchester near London, we were consulted by a pigeon fancier who had critically ill pigeons who died after a short time with symptoms of severe tightness of the chest, but also PMV-like symptoms, like twisted weak necks just before they died. Also, they were drinking more than usual and had dirty green slimy droppings. At first, it reminded me of Adeno type II. In this rapidly fatal disease, however, the droppings are bright yellow (due to the severe destructive liver infection). The mortality is acute within 20 hours!