Protect Your Backyard Birds from Disease

I have spent years studying, observing and feeding bird in my backyard. This passion for birds has led me to research and write about ways to protect backyard birds from diseases.

While there is evidence suggesting a rise in reported cases sick birds, attributing this solely to an actual increase in disease prevalence is not conclusive. Photo: Susy Morris.

The Growing Concern of Bird Diseases in North American Backyards

We enjoy our backyard birds in countless households across North America. However, there is a growing concern: the increasing prevalence of diseases affecting our backyard birds.

Is the perceived increase in bird disease real? 

Determining a definitive increase in backyard bird diseases is a complex issue with no straightforward answer. While there is evidence suggesting a rise in reported cases and mortality rates, attributing this solely to an actual increase in disease prevalence is not conclusive. 

Here’s a breakdown of the evidence:

  • Increased reports of outbreaks: Wildlife rehabilitation centers and birdwatchers report a surge in cases of diseases like trichomoniasis, avian pox, and salmonellosis in backyard birds.
  • Species affected: The spectrum of affected species is widening, impacting a greater number of species that visit backyards feeders.
  • Mortality rates: Studies suggest disease outbreaks can lead to significant mortality in backyard bird populations, raising concerns about long-term sustainability.

Why are we seeing this rise in  backyard bird diseases?

Several factors may contribute to this concerning trend:

  • Habitat loss and fragmentation: Loss of natural habitats due to urbanization and deforestation forces birds to rely on concentrated food sources like feeders, increasing the risk of transmission through contaminated surfaces and close contact.
  • Climate change: Shifting weather patterns and temperature fluctuations can disrupt the natural changes in food availability during critical periods of birds’ annual cycle. This uncertainty and a period of food scarcity may weaken bird immunity, making them more susceptible to disease.
  • Human activities: Unhygienic practices like using dirty feeders and neglecting bird bath maintenance can create breeding grounds for pathogens. Additionally, the introduction of non-native bird species can expose native populations to new diseases.
  • Increased surveillance: Advances in disease detection and reporting contribute to a more accurate picture of the problem, but may also give the impression of a higher prevalence compared to the past.

Understanding Common Backyard Bird Diseases

Pay attention to changes in bird activity, feeding patterns, or appearance.

Backyard bird feeders provide a vital source of food for our feathered friends, but they can also become breeding grounds for disease if not maintained properly. Here’s a breakdown of how diseases spread and some common backyard bird illnesses:

Ways Bird Diseases Spread

  • Direct contact: This is the most common transmission method, especially through beak-to-beak contact during feeding, mating, or aggression.
  • Contaminated food and water: Dirty feeders, stagnant water sources, and moldy bird seed harbor bacteria, viruses that birds can ingest.
  • Vectors: Mosquitoes and ticks carry diseases like West Nile virus and avian malaria and transmit them to birds when they bite.
  • Environmental contamination: Bird droppings, feathers, and other debris can contaminate surfaces like feeders and birdbaths, serving as reservoirs for pathogens.

Common Backyard Bird Diseases

Bear in mind that this list is not exhaustive, and symptoms can vary depending on the disease and individual bird. If you suspect a bird is sick, it is crucial to contact a wildlife rehabilitator, veterinarian, or county extension office for proper diagnosis and treatment.

1. Avian Pox:

  • Symptoms: Wart-like lesions on beak, legs, and eyes, often accompanied by lethargy and drooping wings.
  • Appearance: Lesions can be red, gray, or brown and crusty.
  • Transmission: Direct contact and contaminated feeders.

2. Salmonellosis:

  • Symptoms: Diarrhea, lethargy, ruffled feathers, and loss of appetite.
  • Appearance: Birds may appear dehydrated and weak.
  • Transmission: Contaminated food and water, often from droppings of infected birds.

3. House Finch Disease:

  • Symptoms: Red, swollen, runny, or crusty eyes, conjunctivitis, and difficulty breathing.
  • Appearance: Crusted eyelids may obscure vision.
  • Transmission: Direct contact, contaminated feeders, and possibly mosquitoes.

4. West Nile Virus:

  • Symptoms: Difficulty breathing, coughing, sneezing, and diarrhea.
  • Appearance: Birds may appear lethargic and have ruffled feathers.
  • Transmission: Mosquito bites.

5. Trichomoniasis:

  • Symptoms: Difficulty swallowing, weight loss, drooling, and regurgitation.
  • Appearance: Birds may appear emaciated and weak.
  • Transmission: Contaminated food and water, often from droppings of infected birds.

Learn More about other Diseases that May Affect Backyard Birds.

What can I do to keep my backyard bird feeding station free from disease?

Maintaining a clean and healthy feeding environment is an ongoing process. Consistent effort and vigilance will help you keep your backyard birds happy and healthy for years to come.

The following tips are intended to help you create a healthy, diverse backyard habitat that significantly reduces the risk of disease at your bird feeding station and enjoy the company of healthy and thriving birds.

Hygiene and Maintenance:

  • Clean your feeders regularly: Do this at least twice a week, especially during warm weather. Disassemble the feeder and scrub all parts with hot soapy water, followed by a 10% bleach solution (1 part bleach to 9 parts water). Rinse thoroughly and let air dry completely before refilling.
  • Replace worn-out feeders: Cracked or damaged feeders harbor bacteria and encourage mold growth. Opt for feeders made of easy-to-clean materials like stainless steel or ceramic.
  • Provide fresh, clean water: Clean and refill bird baths regularly, removing any algae or debris. Consider using a circulating birdbath with a filter to prevent stagnant water.
  • Move feeders regularly: This may be difficult but it helps prevent the accumulation of droppings and food waste under the feeder, reducing the risk of contamination. Alternatively, maintain the area under the feeders free from food waste accumulation. 

Food and Habitat Management:

  • Offer a variety of healthy foods: Don’t rely solely on birdseed. Supplement with fruits, nuts, suet, and other natural foods to provide a balanced diet and boost bird immunity.
  • Rotate your food sources: Avoid offering the same food for extended periods. This can attract birds with specific diseases and encourage them to linger, increasing the risk of transmission.
  • Manage spills and debris: Promptly remove any spilled food or debris from under the feeder to prevent attracting pests like rodents and insects, which can carry diseases.
  • Plant native vegetation: This attracts a wider variety of birds and provides them with natural food sources, reducing reliance on feeders and potentially reducing disease transmission.

Bird Observation and Community:

  • Monitor bird behavior: Pay attention to changes in bird activity, feeding patterns, or appearance (e.g., ruffled feathers, lethargy). If you suspect a bird is sick, remove it from the feeder and contact a wildlife rehabilitator or veterinarian.
  • Discourage overcrowding: Use multiple feeders spaced apart to avoid competition and crowding, which can facilitate disease transmission.
  • Educate other backyard birders: Share your knowledge about hygiene and disease prevention practices with other bird enthusiasts in your area.
  • Consider using bird-friendly disinfectants: Some commercially available disinfectants are specifically formulated for bird feeders and are less harmful to birds and the environment than bleach.

How to recognize and Respond to Sick Birds and disease Outbreaks

While watching birds in your backyard brings joy, it’s important to be able to recognize signs of illness and respond effectively. Remember, never attempt to treat sick birds yourself. Here’s how to navigate situations involving sick birds and potential outbreaks:

Recognizing Sick Birds:

  • Observe behavior changes: Decreased activity, lethargy, loss of appetite, difficulty flying or perching, unusual vocalizations.
  • Check appearance: Ruffled feathers, drooping wings, discharge from eyes or beak, abnormal growths or lesions.
  • Monitor feeding patterns: Avoidance of feeders, difficulty swallowing, dropping food.

When to Contact a Professional:

  • If you suspect a bird is sick, isolate it from other birds immediately. This minimizes the risk of transmission.
  • Contact a wildlife rehabilitator or veterinarian experienced in bird care. They can diagnose the illness and provide appropriate treatment.
  • Do not attempt to handle the bird yourself unless absolutely necessary. This can further stress the bird and increase the risk of transmission to you.

Reporting Outbreaks:

  • If you suspect a disease outbreak affecting multiple birds, report it to your local wildlife agency immediately. This helps track disease patterns and implement control measures.
  • Provide details like species affected, observed symptoms, and location of feeders or birdbaths.
  • Cooperate with any investigation or recommendations from wildlife officials.


  • Early detection and intervention are crucial for bird recovery.
  • Wildlife professionals have the expertise to handle sick birds safely and effectively.
  • Reporting outbreaks helps protect bird populations and prevent further spread.

Frequently Asked Questions

This Blue-Gray Gnatcatcher on the ground may appear sick, but it is either anting or taking a dust bath, and it is fine. Photo: Ed Rizer.

How often should backyard bird feeders be cleaned to ensure avian health?

Bird feeders should be cleaned at least once a month to ensure avian health. If there are signs of disease in your backyard birds, it is recommended to clean the feeders more frequently. If you notice any sick birds, remove the feeders immediately and clean them thoroughly before putting them back out.

Which types of bird feeders are least likely to contribute to disease transmission among birds?

Bird feeders with smooth surfaces, such as tube feeders, are less likely to contribute to disease transmission among birds. Platform feeders and hopper feeders with large perches can attract more birds and increase the potential for disease transmission. It is also important to provide multiple feeding stations to reduce crowding and the potential spread of disease.

What are the recommended practices for disposing of seed and water that may be contaminated?

Seed and water that may be contaminated should be disposed of in a sealed plastic bag and placed in the trash. Do not compost or recycle contaminated seed or water. It is also important to clean the area where the contaminated seed or water was located with a 10% bleach solution to prevent the spread of disease.


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