Contributing author Enrique Moreno
Aspergillum is also known as Mitotic Pneumonia
as well as Breeders Pneumonia. The fungus known as Aspergullusfumigatus
though its cousin Aspergillum Niger on occasion causes it
causes it.
Aspergilla is a very huge economic devastator
of chicken farms and is frequently also found as the culprit
in respiratory sickness in flock birds as in wild and aviary
bred birds too.
In the early 1800s mold was discovered growing
in the air sacs of waterfowl. The first time it was described
as the cause of lesions in the air sacs was in 1842 in a Royal
Chaffinch (Fringilla montifringilla). Not until 1912 was the
aspergilla was written about by De Jong in canaries in which
he noticed these manifested as tiny whitish yellow crusted
bumps on the tongue, upper and lower mouth membranes and on
the upper syrinx, larynx, trachea, bronchi and in the lungs.
Aspergillum spores are found growing throughout
the entire world in great quantities on days that the weather
is favorable and there is an ample food and oxygen supply.
They are very hardy and resist even the most weather conditions,
and as so, they are extremely hard to get rid of.
Transmission
These attack your birds in relation to the
following criteria:
- There are an increased number of spores in the air:
- Your birds are exposed to the infected air for enough
time:
- Depending on the age of your birds, the youngest and oldest
are most affected:
- You over use antibiotics, especially the tetracycline
based ones and/or you are providing anti-inflam-matory drugs
to your birds:
- Malnutrition:
- Your aviary or cage has poor ventilation and/or conditions
favorable to the inhalation of already formed spores:
- Presence in the air of respiratory irritators (ammonias,
tobacco smoke, gases caused by disinfectants and others):
- Communicable diseases.
An example of the effects of stress as related
to the susceptibility to the Aspergillum in birds is as follows:
regular sea gulls that seem to be healthy, when caught in
areas of a low density of Aspergillum spores and kept captive
tested positive for sickness after a while though chickens
kept on the same premises did not get sick at all. The most
frequent method of contact is by breathing spores in the air.
The one other way these spores can begin to grow in the birds
is when transferred in an injury, especially to the air sacs.
Aspergillum is a strictly an environmental
transferred sickness and cannot pass form one bird, person
to another. The infections or other sickness that the birds
get during this time that kill them are because of the depressed
immune system. Healthy birds exposed to high concentrations
of these spores are resistant. Penguins (as are other water
fowl and reptiles) are very susceptible to falling pray to
Aspergillum, especially those that live in captivity. Perching
birds and psittacines are very much less susceptible. For
these many years now of our avian clinic the most common birds
with Aspergillum that have been brought to us are the African
Grays, Blue Fronted Amazons and "mainates."
Birds have a rather efficient system to keep
their respiratory systems clean; it consist of mucus covering
of the entire system that acts like a mop that eliminates
them from the system (out the mouth and nose) before they
can germinate. The abundance of dust with a low humidity provokes
the paralyzation of this form of defense.
Aspergillum and other fungi grow rapidly
in decomposing organic mater. A damp type material used in
building nest will favor its growth, contaminating the eggs
and in turn the youngsters born in said nest. Dusty or wormy
feed will also encourage the growth of fungi spores.
Symptoms
Symptoms can appear in from almost unnoticeable
forms to chronic illness.
Acute Aspergillum is fatal. This occurs
when the bird inhales a large quantity of the fungi and it
grows very rapidly. The symptoms are: loss of appetite, difficulty
breathing and finally death, usually with no prior notice
of sickness.
Chronic Aspergillum is much more the
common form of the sickness, presenting itself typically in
small nodules or spread out in the lungs or air sacs. The
nodules you see will be of white, yellow or green usually
on the syrinx, larynx, trachea and bronquials are mostly the
areas involved. The symptoms are variable: difficulty breathing,
listlessness, depression, and going light. The fact it, this
sickness attacks the respiratory system right at the beginning
and these are the very first signs of this illness. Some birds
even seem well but in the autopsy, the lesions are present.
Weakness brought on by bacterial or viral
infection, or some parasite give the Aspergillum fungi a very
comfortable and opportune dwelling place and many times cover
the actual cause of death.
Not all Aspergillum are fatal.
Lesions affecting the upper respiratory tact
(trachea, syrinx [pl. syringes] and bronchi) are usually frequently
associated with:
- Voice changes (less volume, change of tonal quality when
talking or vocalizing.
- Audible breathing sounds.
- Respiratory difficulty: frequently this symptom is first
noticed after a prolonged or moderate period of activity
or exercise.
- On occasion the Aspergillum affect the Nervous System,
producing lack of coordination in movements or even paralysis.
Diagnostics
Confirming the sickness in the bird is rather
difficult when it is still alive. Once dead, the findings
of lesions in the respiratory tract would be proof to you.
The clinical history, laboratory analysis, x-rays, endoscopes
and so forth are that can help us in the diagnosis.
A couple of other sicknesses can manifest
themselves with some of the same symptoms, such as are Ornitosis
and Megabactosis.
In general, there is little hope, with or
without treatment.
Treatment
Application of treatment is rather insidious,
many times being of intravenous method. There are several
medications that are helpful but all of them have drastic
side effects. Thus, it stands only reasonable to find a specialized
avicultural veterinarian in order that the bird is properly
treated according to the type it is.
Control
The best form of control against this sickness
is its prevention. A dirty cage, bed or housing is the culprit.
Reducing the amount of dust by providing better ventilation
helps a lot in preventing contamination. Of course, natural
ventilation is better than forced air.
Another way to prevent Aspergillum is to
reduce the stress in your birds by minimizing such as: malnutrition,
fecal buildup, use of antibiotics, and unnecessary amounts
of food….
© Enrique Moreno
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