Chicken Aflatoxicosis: Moldy Feed Poisoning and Liver Damage

Poison Emergency

Think your pet may have been poisoned?

Call the Pet Poison Helpline for 24/7 expert guidance on poisoning emergencies. Don't wait — early treatment can be lifesaving.

Call (844) 520-4632
Quick Answer
  • See your vet immediately if your chicken is weak, not eating, bruising, bleeding, jaundiced, or if several birds decline after a feed change.
  • Aflatoxicosis happens when chickens eat feed contaminated with aflatoxins, toxins made by Aspergillus mold on corn, peanuts, cottonseed, and other grains.
  • The liver is the main organ affected, but aflatoxins can also reduce immunity, slow growth, lower egg production, and increase flock losses.
  • Diagnosis usually combines history, exam findings, bloodwork or necropsy, and testing the suspect feed for aflatoxins.
  • Treatment focuses on stopping the contaminated feed, supportive care, and managing liver injury because there is no specific antidote.
Estimated cost: $95–$1,500

What Is Chicken Aflatoxicosis?

Chicken aflatoxicosis is a poisoning syndrome caused by aflatoxins, a group of toxins produced by certain Aspergillus molds. These toxins can contaminate grains and mixed feeds in the field or during storage, especially when heat, moisture, drought stress, or insect damage are involved. In chickens, the liver is the main target, so affected birds may develop liver injury, poor growth, weakness, reduced egg production, and in severe cases sudden death.

Chickens are generally considered more resistant than ducklings or turkey poults, but they are not immune. A low-level exposure over time can still harm a backyard flock, especially young birds, stressed birds, or birds with other illnesses. Chronic exposure may look less dramatic than an acute poisoning event, but it can still cause meaningful losses through poor thrift, lower feed efficiency, and immune suppression.

One important point for pet parents: feed does not have to look obviously moldy for aflatoxins to be present. If your flock becomes ill after opening a new bag of feed, using older stored grain, or feeding damp or musty rations, your vet may consider aflatoxicosis as part of the workup.

Symptoms of Chicken Aflatoxicosis

  • Reduced appetite or refusal to eat
  • Poor growth or weight loss
  • Lethargy, weakness, or drooping posture
  • Pale comb or wattles from anemia or poor condition
  • Yellow discoloration of tissues or enlarged, fatty liver on necropsy
  • Bruising, bleeding, or small hemorrhages due to clotting problems
  • Drop in egg production or poorer shell quality
  • Loose droppings or general digestive upset
  • Higher-than-expected illness from secondary infections
  • Sudden death in severe exposures or when multiple birds are affected

Signs can be vague at first. Many chickens show general unthriftiness before a pet parent notices a clear emergency. In a flock, the pattern matters: several birds eating poorly, growing slowly, laying less, or becoming weak after a feed change should raise concern.

See your vet immediately if a chicken is collapsing, bleeding, jaundiced, severely weak, or if multiple birds are sick at once. If a bird dies unexpectedly, ask your vet whether necropsy and feed testing would help identify a toxin problem before more birds are exposed.

What Causes Chicken Aflatoxicosis?

Aflatoxicosis is caused by eating feed contaminated with aflatoxins, most often from Aspergillus flavus or related molds. Corn, peanut products, cottonseed meal, rice, and other cereals are common risk ingredients. Contamination can happen before harvest or during storage, and warm temperatures plus moisture make the problem more likely.

Feed may become risky after drought-stressed crop seasons, insect-damaged grain harvests, poor storage ventilation, condensation inside bins, torn bags, or long storage times in humid conditions. Backyard flocks can also be exposed through old scratch grains, damp treats, or homemade feed mixes stored in garages, sheds, or barns.

Dose and duration both matter. A very contaminated feed can cause acute illness, while lower contamination over days to weeks may lead to slower growth, immune suppression, poor laying performance, and chronic liver damage. Young birds are usually more vulnerable than healthy adults, and birds already dealing with parasites, infection, heat stress, or poor nutrition may have a harder time coping.

How Is Chicken Aflatoxicosis Diagnosed?

Your vet diagnoses aflatoxicosis by putting several pieces together rather than relying on one single test. The history is important: recent feed change, musty or damp feed, several birds affected, poor growth, lower egg production, bleeding problems, or sudden deaths. Your vet may also ask about storage conditions, feed brand, lot number, and whether other animals ate the same ration.

Testing may include a physical exam, bloodwork to look for liver injury and protein changes, and sometimes clotting tests if bleeding is a concern. In birds that die, necropsy can be especially helpful. The liver may appear enlarged, pale, yellow, friable, or hemorrhagic, and tissue samples can be submitted for histopathology.

Feed analysis is often the most useful confirmatory step. Your vet may recommend sending the suspect feed to a diagnostic laboratory for aflatoxin testing. For backyard poultry, veterinary diagnostic labs such as university avian health programs can help with necropsy and flock investigations. Because signs overlap with infection, nutritional disease, and other toxins, your vet may also rule out additional causes before making a final diagnosis.

Treatment Options for Chicken Aflatoxicosis

Spectrum of Care means you have options. Here are treatment tiers at different price points.

Budget-Conscious Care

$95–$300
Best for: Mild signs, early suspected exposure, or pet parents needing a practical first step while stopping the source right away.
  • Urgent exam for one chicken or basic flock consultation
  • Immediate removal and disposal or isolation of suspect feed
  • Switch to fresh, quality feed and clean water
  • Home supportive care plan directed by your vet
  • Basic monitoring of appetite, droppings, weight, and flock losses
Expected outcome: Fair if exposure is caught early and liver damage is limited. Guarded if birds are already weak, bleeding, or if multiple birds are affected.
Consider: Lower upfront cost, but less diagnostic certainty. Without lab work or feed testing, it can be harder to confirm the cause or estimate long-term flock impact.
Most Common

Recommended Standard Treatment

$300–$800
Best for: Most backyard flock cases where birds are ill enough to need confirmation, prognosis guidance, and a clearer plan for the rest of the flock.
  • Veterinary exam and flock history review
  • Bloodwork when feasible to assess liver injury and protein changes
  • Feed sample submission for aflatoxin testing
  • Targeted supportive care such as fluids, nutritional support, and treatment of secondary problems as directed by your vet
  • Necropsy and tissue submission for birds that die during the outbreak
Expected outcome: Variable. Birds with mild to moderate exposure may recover after the feed is changed, but production losses and slower recovery can continue for weeks. Prognosis worsens with severe liver injury or clotting problems.
Consider: More complete information and better flock decision-making, but higher cost range and possible delays while waiting for feed or tissue results.

Advanced / Critical Care

$800–$1,500
Best for: High-value birds, severe weakness, active bleeding, repeated sudden deaths, or situations where a pet parent wants the fullest diagnostic picture.
  • Emergency stabilization for severely affected birds
  • Hospitalization, injectable fluids, assisted feeding, and close monitoring
  • Expanded bloodwork and coagulation assessment when available
  • Advanced necropsy or histopathology for flock-level investigation
  • Consultation with an avian or poultry-focused veterinarian and diagnostic laboratory
Expected outcome: Guarded to poor in critical cases, especially when birds are jaundiced, bleeding, or profoundly weak. Some survivors may still have lasting liver or production effects.
Consider: Most intensive option with the highest cost range. It may improve monitoring and decision-making, but there is still no antidote and some birds decline despite aggressive care.

Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.

Questions to Ask Your Vet About Chicken Aflatoxicosis

Bring these questions to your vet appointment to get the most out of your visit.

  1. Do my chicken’s signs fit aflatoxicosis, or are there other liver or flock diseases you are more concerned about?
  2. Should I stop this feed for the whole flock right now, and what should I switch to while we investigate?
  3. Would bloodwork, necropsy, or feed testing give us the most useful answers for the cost range I can manage?
  4. Are my other chickens at risk even if they are not showing symptoms yet?
  5. What supportive care can I safely provide at home, and what warning signs mean a bird needs urgent recheck?
  6. Could this exposure affect egg production or long-term liver health in birds that survive?
  7. Should I save the feed bag, lot number, and a sample for testing or possible reporting?
  8. What storage changes would most reduce the chance of this happening again?

How to Prevent Chicken Aflatoxicosis

Prevention starts with feed quality and storage. Buy feed from reputable suppliers, avoid damaged or outdated bags, and use feed within a reasonable time instead of storing large amounts for long periods. Keep feed in a cool, dry, well-ventilated area, ideally in clean containers that reduce moisture, pests, and condensation. Do not feed rations that smell musty, feel damp, are clumped, or show visible mold.

It also helps to watch higher-risk times of year. Hot weather, drought-stressed crops, insect-damaged grain, and humid storage conditions all increase risk. If your area has had crop quality issues, ask your feed supplier about quality control and turnover. For backyard flocks, be cautious with homemade mixes, old scratch grains, and treats stored in sheds or garages.

If you suspect contamination, stop feeding the product immediately and contact your vet before more birds are exposed. Save the bag, lot code, and a sample of the feed in a sealed container. That information can help your vet and a diagnostic lab investigate the problem faster and may protect the rest of your flock.

Find a Vet Near You