All About House Finch Eye Disease: A Guide for Backyard Birders

Red, swollen eyes, crusty eyelids, and a struggle to see. These are the telltale signs of House Finch Eye Disease, a contagious bacterial infection plaguing our house finches. This backyard bird disease is raising concerns across the country. While it’s not a threat to humans, House Finch Eye Disease can significantly impact bird populations. Let’s dive into the causes, symptoms, prevention tips, and what you can do to help backyard birds overcome this disease.

Female house finch infected with eye disease.

What is House Finch Eye Disease?

House Finch eye disease, also known as mycoplasmal conjunctivitis, is a contagious bacterial infection affecting the eyes of, primarily, house finches. It is caused by the bacterium Mycoplasma gallisepticum, the same one responsible for respiratory infections in poultry.

Learn More about other Diseases that May Affect Backyard Birds.

Symptoms of House Finch Eye Disease:

  • Red, swollen, and runny eyes: This is the most common symptom, often accompanied by crusting around the eyelids.
  • Difficulty opening or keeping eyes open: The swelling and crusting can obstruct vision, making it difficult for birds to see and feed.
  • Discharge from eyes: The discharge can be clear, white, or yellow, and may crust on the feathers surrounding the eyes.
  • Loss of appetite and lethargy: Infected birds may become withdrawn and inactive due to discomfort and difficulty foraging.
  • Head tilt: In severe cases, the infection can cause facial paralysis, leading to a head tilt.

Causes of House Finch Eye Disease:

Male house finch with the disease. Photo: Kathy Diamond
  • Direct contact: Transmission occurs primarily through contact with infected birds’ eyes or nasal discharge, often at crowded feeders or birdbaths.
  • Contaminated surfaces: The bacteria can survive for several hours on surfaces like feeders, birdbaths, and ground, infecting birds through contact.
  • Mosquitoes: Recent research suggests that mosquitoes may play a role in transmitting the disease, but this is still being investigated.

Diagnosis of House Finch Eye Disease:

  • Visual examination: Veterinarians can often diagnose the disease based on the characteristic symptoms.
  • Laboratory tests: In some cases, swabs from the eyes may be tested for the presence of the bacteria.
  • Differential diagnosis: Other diseases, such as avian pox and trichomoniasis, can also cause similar symptoms, so accurate diagnosis is crucial.

Is there a Treatment for House Finch Eye Disease?

Unfortunately, there is no specific treatment for House Finch eye disease in wild birds. Antibiotics are not generally effective, and attempting to treat individual birds is often impractical. 

However, supportive care, such as providing clean food and water and minimizing stress, can help birds recover on their own.

Is House Finch Eye Disease contagious to other birds?

Yes, House Finch eye disease is highly contagious among birds, primarily house finches. It can also potentially spread to other bird species through contact and contaminated surfaces.

Is House Finch Eye Disease Contagious to humans?

The good news is that House finch eye disease is not considered contagious to humans. While the bacteria responsible for House finch eye disease (Mycoplasma gallisepticum) can also infect humans, the strain that causes this disease in birds is different from the one that affects humans.

Therefore, you don’t need to worry about catching house finch eye disease from your backyard birds or by handling feeders or birdbaths. However, it’s always good practice to maintain proper hygiene, which includes washing your hands after handling bird feeders and birdbaths, as a general precaution against any potential pathogens.

Risk Factors for House Finch Eye Disease:

  • Crowded feeders and birdbaths: Close contact at feeders increases the risk of transmission.
  • Poor hygiene: Dirty feeders and birdbaths can harbor the bacteria.
  • Stress: Stressed birds may be more susceptible to infection.

Preventing House Finch Eye Disease:

Not only house finches contract the disease but other birds such as cardinals. Photo: Julie Reid.
  • Maintain clean feeders and birdbaths: Regularly clean and disinfect feeders and birdbaths with a bleach solution or vinegar to prevent the bacteria from multiplying.
  • Offer diverse food sources: Provide a variety of food sources to encourage birds to spread out and reduce competition at feeders.
  • Create a natural habitat: Plant native vegetation to attract insects and natural food sources, reducing reliance on feeders.
  • Monitor bird behavior: Observe birds for signs of illness and remove any sick birds from feeders to prevent transmission.
  • Report outbreaks: If you suspect an outbreak in your area, contact your local wildlife agency or bird rehabilitation center.

Do Birds Infected with House Finch Eye Disease Survive?

While House Finch eye disease can be serious, many birds do make a full recovery, especially with supportive care and adequate nutrition. However, some birds may suffer permanent vision loss or succumb to complications from the infection.

Only House Finches Get House Finch Eye Disease?

While house finches are the primary victims of House Finch eye disease, other bird species can be infected, including goldfinches, purple finches, and American robins. However, the disease is usually less severe in these species.

Key Takeaways:

1. House finch eye disease (HFE) is a contagious bacterial infection affecting primarily house finches, causing red, swollen eyes and difficulty seeing.

2. Transmission occurs through direct contact, contaminated surfaces, and possibly mosquitos.

3. While no specific treatment exists, clean feeders, diverse food sources, and a natural habitat can help prevent outbreaks.

4. HFE is not contagious to humans, but good hygiene around feeders is always recommended.

5. Many infected birds recover with supportive care, but some may suffer vision loss or complications.

6. Other bird species can be infected, but HFE is usually less severe in them.

7. By understanding and preventing HFE, we can protect backyard bird populations and enjoy their presence.

Learn more about another bacterial bird disease: Salmonellosis.


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