The following explains the causes, signs, and treatments for ​Aspergillus Fumigatus-​Aspergillus (Brooder Pnuemonia) in chickens, poultry, and turkeys.

What is Aspergillus Fumigatus?

"Aspergillus fumigatus  is a pathogen which causes serious respiratory problems in chickens, turkeys, and other poultry. The pathogen A. Fumigatus is most commonly found in indoor farm environments due to inadequate ventilation, dusty living conditions which expose the birds to aerosolized spores which are extremely tiny and light enough to travel through air making it easier for birds to contract the pathogen. A. Fumigatus can spread quickly as it sporulates very easily in poor quality bedding and contaminated feed. "Sporulation is the formation of nearly dormant forms of bacteria . In a limited number of bacteria, spores can preserve the genetic material of the bacteria when conditions are inhospitable and lethal for the normal (vegetative) form of the bacteria"(3). As a result there is a high mortality rate which results in significant economic losses  in poultry production, particularly in turkey production.
"The chronic form affects older birds and looks more sporadic. The respiratory tract is the primary site of A. fumigatus development leading to severe respiratory distress and associated granulomatous airsacculitis and pneumonia"(2).

Signs and Symptoms of ​Aspergillus Fumigatus-Aspergillus (Brooder Pnuemonia)

Signs and symptoms of Aspergillus Fumigatus-Aspergillus (Brooder Pnuemonia) are:

1. Gasping
2. Sleepiness
3. Loss of appetite
4. Convulsions
5. Death

Causes of Aspergillus Fumigatus-Aspergillus (Brooder Pnuemonia)

Poultry need fresh clean dry bedding, fresh mold free feed, fresh clean water, and proper ventilation to prevent Aspergillus Fumigatus (Brooder Pnuemonia). Causes of Aspergillus Fumigatus​-Aspergillus (Brooder Pnuemonia) are:

• Wet bedding
• Unsanitary living conditions
• Not enough ventilation
• Moldy feed
• Introduction of Wild birds
• introduction of one-day-old birds whose down has retained conidia in hatchery facilities.
  

Baby chicks may contract brooder pneumonia if left in unsanitary wet or damp conditions, if wet feed has been left to long, for them to eat or if dust concentrations are too high. When baby chicks appear to be panting or gasping for air they have most likely been exposed to mold spores either from mold on hatching eggs, dusty surroundings, wet bedding, or wet feed that has been fed for more than one day.  (Note: Never use gas or propane heat for brooders as the fumes can cause the chicks breathing difficulties which can quickly result in death).

• Fumigatus, sources of which may include moldy, wet feed; wet bedding; or mold on hatching eggs. Infection occurs when birds inhale large numbers of fungal spores, producing severe inflammation in birds' lungs, air sacs, and sometimes other tissues (2).
• Diagnosis: Respiratory tract cultures and/or microscopic examination of the affected tissues (2).

Wild birds should never have access to your chickens, their feed, water, bedding or play areas. Infected wild birds can fly over your coop or run and their infected droppings can introduce the pathogen to your birds.

Treatment for Aspergillus Fumigatus​-Aspergillus (Brooder Pnuemonia)

Treatment for infected birds can be very expensive and time consuming and the chances for recovery are 50/50. In most commercial operations the infected birds are culled and the poultry houses are cleaned and disinfected before reusing. However, I have had many chickens brought to the sanctuary who made a complete recovery if the condition was caught quickly enough. Once a chicken develops an infection it often leads to other health problems as well. Check your birds every few hours especially if they are in a confined area such as a brooder. If you notice any signs of gasping, listlessness, lack of appetite or excessive sleepiness you can take the following steps to help your birds recover:

1. Remove all birds from the coop or brooder. 
2. Remove all feed and water.
3. Remove all bedding and loose feathers.
4. Clean the coop, feeders, water drinkers, or brooder immediately.
5. Disinfect the coop, feed and water containers, troughs, cups, nipples, etc.
6. Make sure bedding is fresh and dry with no mold.
7. Check your feed for signs of mildew, mold, or wetness before giving it to your birds.
8. Make sure water drinkers or nipples are not leaking.
9. Be sure your coop or brooder is properly ventilated.
10. Check for water line leaks
11. Check for moldy wood
12. Check for mold on bedding such as wood chips, pine bedding, alfalfa, straw, or hay.
13. Check inside your birds mouth for a white coating or clumps of a yellow or white cheesy substance which could indicate they have contracted Moniliasis (Thrush) and treat them for it. (See Moniliasis Treatments)
14. It is common for infected birds to develop Airsacculitis and should be treated if showing symptoms. See Airsacculitis Symptoms and Treatments
15. Treat all bedding with a fungistatic compound to reduce wetness and conditions which allow the pathogen and other bacteria to grow and spread.​

Treatments for infected poultry are nonexistent; therefore, prevention is the only way to protect poultry. Development of avian models of aspergillosis may improve our understanding of its pathogenesis, which remains poorly understood" (2).
​Notes:

• Do not put baby chicks with baby ducks as baby ducks will play in the water causing the bedding to become wet which will in turn create an ideal environment for mold spores to develop.
• Wet feed can quickly develop mold spores particularly during warm weather. When feeding wet feed, do not feed more than the birds can eat in one day. Feed dishes should be cleaned, disinfected, and any  remaining wet feed should be discarded within 24 hours of serving. 
• Never feed your chickens moldy bread, fruit or vegetables or anything with mold on it. A good rule of thumb, if you wouldn't eat it do not feed it to your chickens.

Using Litter In This Way Can Reduce or Eliminate Mold in Your Coop?

Recent studies show that the fungal populations in poultry bedding change over time and can actually reduce or eliminate the chances for respiratory infection as the litter ages. Typically, pine bedding mixed with chicken poo will turn into mold which then turns into a yeast within two months. By using pine bedding and compounds which reduce fungal population and proper ventilation, you can actually use bedding for a much longer time.  As the bedding matures the pH and ammonia levels change. pH and ammonia are the culprits responsible for fungal populations. Within 2-5 years the fungal population stabilizes and mold induced litter respiratory infection is all but eliminated.
"​Minimizing mold growth, maintaining proper litter and relative humidity to reduce spore inhalation, and treating the bedding with fungistatic compounds have been some of the strategies used in the past to lessen potential respiratory infections. As fecal deposition increases on the fresh bedding during the first flock on litter (litter is the combination of bedding and fecal matter), there is rapid shift in the fungal populations. The populations changes from predominantly molds to yeast species during a typical two-month poultry growout cycle. A rapid shift in litter pH (acid to alkaline state) and ammonia which acts as a mold inhibitor is responsible for the change in fungal populations. As the litter ages with increasing number of flocks (sometimes 2-5 years before complete bedding replacement), the fungal population tends to stabilize and the potential for mold-induced litter respiratory infection is all but eliminated. In the past there were concerns with using the moist, acidic, “green” hardwood sawdust due to potential corrosion of the metal equipment (ie. feed pans) in contact with the fresh bedding. With the shift to plastic poultry house equipment this is no longer a major issue in the industry (4). See Factsheet It stands to reason, based on this study of commercial poultry bedding,  that if birds are removed from the bedding when it has matured for less than two months when the yeast starts developing and placed in another coop or if bedding as removed and stored in a dry area until the bedding matured over time (2-5 years) and could be re-used then because the fungal mold would not be able to grow in the matured bedding.  For small backyard operations this may not be very useful information because who wants to have a dirty coop sitting around for 2-5 years but it could be very helpful for larger operations who have poultry houses or large flocks of birds, extra coops, and want to lower their bedding costs.

Coop Ventilation Tips

Brooder Tips

Respiratory Diseases & Treatments

---

References: 

1. Arné, P., Thierry, S., Wang, D., Deville, M., Le Loc'h, G., Desoutter, A., Féménia, F., Nieguitsila, A., Huang, W., Chermette, R. and Guillot, J. (2019). Aspergillus fumigatusin Poultry.
2. ​Penn State Extension. (2019). Respiratory Diseases of Small Poultry Flocks. [online] Available at: https://extension.psu.edu/respiratory-diseases-of-small-poultry-flocks [Accessed 20 Oct. 2019].
3. ​Encyclopedia.com. (2019). Sporulation | Encyclopedia.com. [online] Available at: https://www.encyclopedia.com/science-and-technology/biology-and-genetics/cell-biology/sporulation [Accessed 20 Oct. 2019].
4. ​Udel.edu. (2019). [online] Available at: https://www.udel.edu/content/dam/udelImages/canr/factsheets/utilizing-hardwood-sawdust-poultry-bedding.pdf [Accessed 20 Oct. 2019].