Saturday, July 20, 2024
HomeAnimal HusbandryPoultryAvian Influenza: Signs, Symptoms, and Prevention in Poultry

Avian Influenza: Signs, Symptoms, and Prevention in Poultry


As a 16-year-old member of 4-H, I was introduced to avian flu during a poultry exhibition where my birds were being tested. While they weren’t screening for it that day, I seized the opportunity to speak with the National Poultry Improvement Plan inspector.

I learned about poultry diseases and their prevention and treatment. Since then, my interest in avian illnesses has deepened, especially after acquiring my homestead flock, which I worry might fall victim to avian flu. Reports of avian influenza or bird flu are once again making headlines worldwide.

The current H5N1 HPAI has been confirmed in numerous countries across Asia, Europe, and North America, affecting commercial and wild bird populations. Over 31 million birds have been culled this year to prevent the virus’s further spread.

In this article, we will discuss the symptoms of AI, best practices to prevent its spread, and recommended actions and resources to help those whose flocks test positive for avian influenza.

Avian Influenza: Signs, Symptoms, and Prevention in Poultry
Photo: Cnet

History of Avian Flu

Avian Influenza A (H5N1) had wreaked havoc for years, with its origins tracing back to northern Italy in 1878 when veterinarian Edoardo Perroncito first noticed this highly pathogenic avian influenza (HPAI).

Known as fowl plague, the disease initially puzzled many as it was believed to be a result of another disease, fowl cholera, caused by Pasteurella multocida bacteria. Despite this, outbreaks continued throughout the early 1900s, with China experiencing a devastating outbreak in 1996 that claimed the lives of 40% of aquatic birds.

However, the disease’s most significant impact came in recent years due to its rapid mutations, with North America losing 50 million birds to avian flu during 2014-2015. This disease is a lethal threat to domesticated avian species, including chickens, and wild bird populations.

Protecting endangered bird species is critical to maintaining healthy ecosystems. Although governments focus on safeguarding both domestic and wild birds, hobby farmers worry mainly about their backyard flocks and the devastating implications that avian flu can bring.

Contaminated flocks often require culling, with many larger farms having to take the drastic measure of culling their entire flock to preserve the industry’s integrity. Backyard flocks are not immune to such dangers and are equally susceptible. Therefore, the essential question arises: What measures can one take to avoid the looming tragedy?

Did you know that avian influenza A viruses, although not commonly affecting humans, have been known to infect people with direct or unprotected contact with infected birds or contaminated surfaces? H5N1, a highly pathogenic avian influenza virus, is capable of causing fatalities in both poultry and humans.

Its first documented human case was reported in 1997, and since November 2003, it has claimed the lives of over half of those infected with it. The H7N9 bird flu, on the other hand, poses the most significant potential to trigger a pandemic and is considered a severe threat to public health if it were to cause sustained human-to-human transmission.

Human infection usually occurs through close contact with birds, as they shed the virus in their saliva, feces, and mucous. Thus, exposure to bird droppings is also a possible transmission route.

Avian Influenza to humans
Photo: Daily Express

Signs and symptoms of avian influenza

Avian influenza is a disease that can infect both wild and domestic birds caused by type-A influenza viruses. Migratory bird flight patterns, international trade, and human-wild bird points of cross-contact can influence the spread of AI. The virus is more commonly detected in colder regions due to its resilience in low to freezing temperatures.

The clinical types of influenza virus in poultry include highly pathogenic (HP) and low-pathogenic (LP). HP strains can cause sudden high mortality levels and multi-organ failure, whereas LP strains can form asymptomatic infections, respiratory disease, and/or decreased production.

Symptoms indicating the presence of avian flu in birds include sudden death without any warning signs, purple discoloration of the wattles, comb, and legs, swollen head, eyelids, comb, wattles and hocks, soft-shelled or misshapen eggs, decreased egg production, lack of energy, appetite and coordination, diarrhea, nasal discharge, coughing or sneezing, and ruffled feathers.

Discovering that a chicken or other poultry is ill can be a source of anxiety. Many veterinarians refuse to treat poultry, and it can be challenging to determine the cause of your birds’ symptoms.

According to the University of Minnesota poultry experts, signs of highly pathogenic avian influenza (HPAI) often involve respiratory distress and severe diarrhea followed by a swift death. The authors report that “chickens may develop swelling around the head, neck, and eyes, while the head and legs may become discolored with a purple hue.”

Understanding these symptoms is critical to ensure your birds’ safety. If you notice sudden, high mortality rates or many birds displaying signs of HPAI, immediately contact your veterinarian or local health board.

The University of Minnesota also emphasizes that flocks within 6 miles of confirmed cases should be checked for the virus and may require euthanasia. This is crucial in limiting the virus’s spread, as many cases have been identified within backyard flocks.

Sick poultry often appears chaotic, are less active, eat or drink less, and generally look unwell. It is advisable to isolate sick birds from the rest of the flock. Even if it is not avian flu, separating an ill bird from others can help prevent the spread of other illnesses.

According to the USDA Centers for Disease Control and Prevention, avian influenza viruses seldom infect humans. Nonetheless, it poses a potential threat to a specific group of individuals in direct contact with birds, namely farmers. Symptoms of avian flu in humans include fever, cough, sore throat, body aches, respiratory issues, and nausea and vomiting.

The USDA highlights that bird flu virus infections in people usually occur through close, prolonged, and unprotected contact with infected birds or environments contaminated by their excretions, including saliva and mucus. Therefore, it’s crucial to adopt good hygiene practices when handling poultry to minimize the risk of infection.


Practicing proper handwashing techniques after any contact with birds is vital, not only for avian flu but also for other diseases.

Discover Why Newborn Chicks Die and What You Can Do to Prevent It

How to Prevent Avian Influenza in Poultry

I understand the importance of safeguarding the health and well-being of poultry. Avian influenza is a highly contagious virus that can devastate a flock, spreading rapidly through direct contact with infected birds or contaminated feed, water, equipment, or clothing. Therefore, taking appropriate measures to prevent the introduction and spread of the virus is crucial.

How to Prevent Avian Influenza in Poultry
Photo: abbagetownpetclinic

Biosecurity Tips

Although there is no absolute way to prevent avian flu, there are several measures you can take to help mitigate its spread and keep your flock healthy.

First and foremost is biosecurity, a procedure that safeguards your animals or yourself from harmful biological diseases. While biosecurity doesn’t guarantee complete disease prevention, it can be a great way to drastically reduce the risk of disease spread.

Biosecurity is the first and most essential prevention method at the farm level. To protect your poultry:

  1. Reduce the likelihood of attracting wildlife, and prevent their access to your property.
  2. Remove standing water, grade your property to avoid pooling water, and locate feeding structures on a clean pad.
  3. Keep the area around the barn clean and frequently mow, removing fallen fruits.
  4. Avoid feeding wildlife and cover waste, ensuring that used litter is not piled near the barn.

Wildlife deterrents such as exclusionary netting, screens, and perch deterrents like bird spikes or repellent gel should be installed. Move and replace scare devices frequently to keep wild birds at bay.

During high-risk times, such as an outbreak in the area, keep your birds indoors or ensure wild birds cannot access their feed and water sources. Cover outdoor runs to protect housed birds that may have contact with wild birds.

It is also essential to maintain control over the access of people and equipment to poultry houses. If infected wild birds are in the area, reduce the movement of people, vehicles, or equipment to and from areas where poultry are kept. Change clothes before and after contact with the flock, and ensure visitors do the same.

Maintained sanitation of the property, poultry houses, equipment, vehicles, and footwear. Disinfect regularly, and for commercial poultry owners, clean and disinfect housing at the end of a production cycle. Wash hands thoroughly before and after contact with birds.

To avoid introducing birds of unknown disease status into the flock, acquire birds from sources that verify they are disease-free. Quarantine new birds for two weeks in separate quarters to ensure they are healthy.

Report illnesses and bird deaths immediately to a vet. Quick action will help protect other flocks in the area if the disease is confirmed. Appropriately dispose of manure and dead poultry, following local depopulation and disposal methods guidelines.

Maintain surveillance by following local regulations regarding breeder flock monitoring and testing protocols. Protecting your flock from avian influenza requires diligence and a proactive approach, but the rewards are healthier birds and a thriving poultry operation.

When I was in 4-H, I owned a rabbitry and poultry farm where many customers wanted to tour our farm, but this was impossible due to our biosecurity measures. Allowing visitors onto your farm increases the risk of diseases coming onto your property.

When I think about my biosecurity measures, I consider starting to finish. When I buy new birds, I always quarantine them and ensure that they appear healthy when I purchase them. If I buy directly from a farm, I inspect their facility to see if it is clean and healthy.

I usually ask myself the following questions:

  • Do the animals look healthy?
  • Are the enclosures clean?
  • Are there too many animals in a confined space?

If animals don’t appear healthy or the environment isn’t clean, there is a high risk of disease. Pens filled with dust increase the risk of respiratory issues in birds. Birds that come from high-stress environments like these are more susceptible to illness. Animals crowded into inadequate areas also spread diseases rapidly.

I am careful about whom I allow onto my farm. Limiting the number of people who expose your animals and property to pathogens is essential for your farm’s biosecurity. I do not allow just anyone to visit. When people come, I ask them to wash their hands and disinfect their shoes.

I am always cautious of other poultry owners coming over since anyone could carry diseases on their boots. I prefer farms that don’t allow tours as it shows they are conscious of disease, and the less traffic in and out of their farm, the better.

Feathered Friends

Feeding wild birds may seem harmless and enjoyable, but it significantly threatens your flock’s health. Although it’s natural to observe birds on your farm, wild birds that fly around your coops and feeders can carry avian flu, parasites, and diseases that could be fatal to your birds.

To protect your free-ranging flock, keeping them away from contact with wildlife is necessary. However, preventing wild birds from entering your yard is almost impossible. To reduce the risk of disease transmission, avoid allowing feed to sit out and discourage waterfowl from landing in your pond.

You should also make your yard less appealing to these birds and drain standing water. To maintain proper biosecurity, it’s crucial to disinfect all your poultry equipment, including feeders and waterers, at least once a month. During cleaning, wear gloves and masks, and practice personal hygiene.

It’s also necessary to change your clothing and shower after cleaning. When introducing new poultry to your farm, quarantine them for at least a month away from your existing birds. This way, any diseases they may have can show themselves, and you can take action to prevent transmission.

Finally, having special shoes solely for your coop is an excellent way to protect your flock from external diseases and prevent you from potentially tracking diseases outside your coop.

Related post: A Guide to Preventing and Treating Common Chicken Illnesses

Best practices to help prevent the spread of AI

The prevention and control of avian influenza are of utmost importance for any poultry operation. The use of antiviral compounds is not advised. Therefore, it is recommended to have a robust monitoring system and implement effective biosecurity measures to prevent the spread of the virus.

prevent the spread of AI
Photo: nbcnews

The World Organization for Animal Health recommends humanely culling infected and exposed animals, followed by the appropriate disposal of carcasses and animal products. Furthermore, surveillance, tracing, quarantine, and controls on the movement of poultry and at-risk vehicles are necessary to contain the spread of the virus.

Additionally, proper decontamination of infected premises is essential, followed by a minimum period of 21 days before restocking. Vaccination can be helpful to support eradication programs if combined with other control methods, such as emergency vaccinations, to reduce transmission rates.

In case of a potential outbreak, closely monitoring each flock is vital. If signs of avian influenza are detected, notify the USDA or the state veterinarian immediately. Authorized workers are allowed in and out of the facility, while movements of birds, poultry products, and equipment are restricted.

Depopulation and disposal are required if the birds test positive for avian influenza. Finally, thoroughly cleaning and disinfecting the premises, equipment, and potentially affected areas is necessary before restocking.

Engaging in extracurricular activities such as poultry shows and swaps, or even hunting game birds, may raise concerns about the potential spread of avian flu. While hunting can be safe if precautions are taken, attending shows and swaps can be more complicated.

Current guidelines can be found on maps provided by the CDC to assess the risk level in your area. If no cases are nearby, it may be safe to continue attending these events.

However, it’s essential to remain vigilant of other diseases that can be contracted at these gatherings. Practicing caution and maintaining a healthy flock is vital to ensuring they stay healthy and continue to provide for the farm.

Keeping coops clean and properly disinfecting equipment can help reduce the risk of disease transmission. Ultimately, it’s a personal decision whether or not to participate in extracurricular activities, but taking steps to prevent disease is always a wise choice.

Related  post: Tips to Keep Your Flock Healthy and Happy In Winter



Please enter your comment!
Please enter your name here

Popular posts

Follow Us!