Aspergillosis in Chickens and Other Fungal Infections

Chicken Feather Loss, Red Skin, and Thrush Can be a Fungal Infection.

Aspergillosis in Chickens and Other Fungal Infections

By Brittany Thompson, Georgia

One of my oldest hens and the matriarch of my flock, Chirpy, a six-year-old Rhode Island Red, was diagnosed with a fungal infection through nose swab testing. Chirpy was also featured in my last article on bumblefoot in Backyard Poultry.

The type of fungal infection was called Candida fumata. Chirpy had six different colonies of this fungal infection growing in her. It mostly affected her breathing. It was pricey testing, but worth finding out what was the cause of her respiratory issues since antibiotics were not working. My vet and I tried four different antibiotics before coming to the conclusion that her illness was not bacterial related. Symptoms are similar to respiratory infections and it is a common mistake to treat fungal infections as a respiratory infection, which only makes the fungal infection worse, as I found out.

In July 2015, Chirpy passed away from her fungal infection. I found her one morning under the roosts. I also had a Golden Comet hen, Little Worm, who was four, that recently passed from what I believe to be an internal fungal problem of digestion.

Rapid weight loss was noted, as well as decreased activity, eating more, and fatigue.

What Is a Fungal Infection?

Fungi come in molds, mildews, yeasts, mushrooms and toadstools. Of the more than 100,000 species of fungi only two kinds cause infections — yeast-like and mold-like.

Causes Of Fungal Infections

  • Moldy food (especially processed poultry feeds or corn)
  • Spores in the air or on surfaces
  • Wet weather, high humidity and heat, like found in the southern United States.
  • Bedding materials that mold especially easily, such as some kinds of hay
  • Even after the bedding dries out, dangerous spores can remain.
  • Lack of good sanitation
  • Direct contact with fungus on another infected bird
  • Weak immune system

Types of Fungal Infections:


Mycosis: Fungal infections have gotten more common with the widespread use of antibiotics. Fungal infections tend to prey on birds with lower immunity. The use of antibiotics also kills the naturally occurring body flora residing in their system, which leads to a weakened immune system. Mycosis is grouped by two different methods:

Superficial: affects the skin or mucous membranes.

Deep: affects internal organs, usually the lungs or crop, which is what Chirpy had.

Moniliasis (sour crop, thrush): This is a disease that primarily affects the upper digestive tract of all birds and is characterized by whitish, thickened areas of the crop and proven triculus, erosions in the gizzard, and inflammation of the vent area. It is caused by a yeast-like fungus (Candida albicans). Poultry of all ages are susceptible to the effects of this organism. Chickens, turkeys, pigeons, pheasants, quail, and grouse are species most commonly affected as well as other domestic animals and humans. The Candida organism is widely spread and is found throughout the world. Moniliasis is transmitted by ingestion of the causative organism in infected feed, water or environment. Unsanitary, unclean water can be a nesting ground for the organism. The disease luckily doesn’t spread directly from bird to bird. The organism grows especially well on corn, so infection can be introduced by feeding moldy feed.This infection produces no specific symptoms.

Mycotoxicosis: It is known that certain strains of fungi (molds) growing in feed or feed ingredients can produce toxins that, when eaten by man or animals, can cause a very lethal disease called mycotoxicosis. The toxins produced by these fungi are very toxic and rivals the botulism toxin for toxicity. Mycotoxicosis is caused by ingestion of toxic substances produced by molds growing on feed, feed ingredients and possibly litter. Several types of fungi produce toxins that may cause problems in poultry, but of primary concern are substances produced by the Aspergillus flavus fungi and are thus called aflatoxins. Aspergillus flavus is a common mold that grows on many substances, and grows especially well on grains and nuts. Several other fungi also produce toxins that cause the disease, so be sure to keep litter as clean as possible. I would not recommend using hay or any litter that molds quickly.

Aspergillosis in chickens: Aspergillosis has been observed in almost all birds and animals, including in humans. The disease is observed in one of two forms; acute outbreaks in young birds with a high mortality in young birds, and a chronic condition affecting adult birds. This type of fungal infection is highly contagious. Birds must be in isolation if they have been diagnosed with this infection. The condition is caused by Aspergillus fumigatus, a mold or fungus-type organism. These organisms are present in the environment of all poultry. They grow readily on many substances such as litter, feed, rotten wood, and other similar materials.The bird comes in contact with the organisms through contaminated feed, litter, or environment. The disease does not spread from bird to bird. Most healthy birds can withstand repeated exposure to these organisms. Inhalation of large amounts of the infectious form of the mold or reduced resistance of the bird apparently results in fungal repiratory infections in chickens. The more chronic form in older birds usually results in loss of appetite, gasping or coughing and a rapid loss of body weight. Mortality is usually low and only a few birds are affected at one time. If you do take your bird to the vet and has been confirmed to have aspergillosis, your bird will have to be put in isolation. (The website by MSU really helped explain aspergillosis in chickens the best.).

Symptoms of Fungal Infections

  • Weakness due to intestinal fungi that does eat your bird’s food and can cause damage to organs that digest food.
  • Overall uncoordination of the bird
  • Difficulty breathing, gurgling noises, and respiratory symptoms. Air passages are restricted by fungi.
  • Fatigue
  • Bird may not be very interested in eating and is losing weight
  • Some bright green and watery droppings, also known as vent gleet.
  • Droppings may stick to vent area.
  • Anemia
  • Infertility and reduction in laying
  • Respiratory system may be restricted and bird isn’t able to use panting to cool down as well as normal
  • Internal bleeding is possible
  • Death may occur from a prolonged, severe infection.

Possible Treatments/Prevention

I have never personally tried Oxine AH, but have heard good things about it. It kills bacteria, viruses, and fungi. It can be used by fogging or spraying coops and the surrounding area and any equipment used. It’s also used to treat water. More information on Oxine AH can be found by doing a Google search if interested.

  • Keep litter as clean as possible. I recommend using sand and have been using this for many years in my coops. I also use Sweet PDZ Coop Refresher and Red Lake Earth DE in my coops.
  • If possible, get a veterinarian to test your chicken. The testing can narrow down the type of fungal infection your chicken has and proper medication can be found.
  • Do not feed your chickens anything moldy. Feed needs to be as fresh as possible. Check the dates your feed was made. This date can usually be found stamped on the bottom of a feed bag. I do not use feed more than a month old, just in case.
  • If the infection is really bad, medication might need to be used, but antifungals are pretty harsh on a bird’s system.
  • Keep birds in well ventilated areas.
  • Probiotics can be a good way to introduce more good bacteria to kill off the fungi. Just be careful how much probiotics you give yours birds. Don’t overdo it. Also do not combine antibiotics and probiotics at the same time.


  • Fresh garlic is great as a natural antifungal. You can feed it directly in crushed up bits in their feed or use a liquid form in their water.
  • Raw, unfiltered from the mother apple cider vinegar added to their water can also help prevent infections.
  • Damerow, Gail. The Chicken Encyclopedia. North Adams, MA: Storey Pub., 2012. Print.
  • Dr. Campbell, Dean, Heart of Georgia Animal Care, Milledgeville, GA
    Mississippi State University Extension
  • Burek, Susan. Moonlight Mile Herb Farm
One thought on “Aspergillosis in Chickens and Other Fungal Infections”
  1. My chickens were giving me 1 to 11/2 dozen eggs a day. We have caught 3 coons and 2 possum. We are still down to less than 6 to 8 eggs a day. Could the chickens still be scared?

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