Occasionally chickens can either hatch blind or without eyes, or can go blind as a result of disease or injury to one or both eyes. Like with people, blindness can make things more challenging, however there are many blind chickens who are able to live happy, healthy lives. Chickens that are born with or acquire disabilities should not be so quickly cast aside---as there are many people who have kept and continued to care for blind chickens.
Signs of Blindness
Some signs that your chicken may have impaired vision include:
- Bumping into objects
- Acting like they aren't sure where to go
- Pecking at air
- Clumsiness
- Depression
- Reduced activity
- Enlarged or irregular-shaped pupils
- Cloudiness or discoloration of the eyes
Diagnosis of Blindness in Chickens
A quick and easy test that can be performed, to check whether a chicken is blind, is to slowly (don't use rapid movements because otherwise they can feel the airflow and sense the motion) move your finger towards the affected eye. A chicken that does not blind or try to move out of the way is likely blind.
In 2006, University of Florida scientists developed a gene therapy that helped restore sight to chicks with a certain genetic defect that were usually born blind. The genetic defect was associated with the Rhode Island Red chicken breed, that carry a defect preventing them from producing an enzyme essential for site. The condition is very similar to Leber congenital amaurosis type 1, or LCA1, a genetic defect in humans that causes blindness.
Cloudiness or discolored eye
Misshaped or unequally shaped pupils
Limited to little reaction to external stimuli
Inability to recognize food or water when right in front of them
Consistent chirping if newly hatched chick
- History
- Clinical signs
- Eye exam
Management changes: Don't let blind chickens free range where they are at a great risk of predator attacks, as they will be easy prey without their eyesight.
Keep birds confined within a limited area that effectively excludes predators from accessing the chickens.
Monitor the flock social hierarchy daily to ensure that the blind chicken does not get picked on by the other birds. There have been many incidences where blind chickens find companions which stay by their side and defend them, but in other cases they may not.
Keep an eye on the blind chicken's rate of weight gain or whether they lose any weight, which may result if they are having trouble getting to the food prior to the other chickens' eating it all.::
Make sure to promptly and appropriately treat chickens with early signs of respiratory illness, as many can often lead to chronic sinusitis, often resulting in blindness.
Good, blind chickens can usually live happy and healthy lives with just a little supportive care and help.
- McPherson MC, Delany ME.. Virus and host genomic, molecular, and cellular interactions during Marek's disease pathogenesis and oncogenesis. Poult Sci (2016)
- Valdez, Diego J., et al. Circadian Control of the Pupillary Light Responses in an Avian Model of Blindness, the GUCY1* ChickensBlind Birds and Pupillary Light Responses Investigative ophthalmology & visual science (2015)
- Hocking, P. M., Haldane, K. A., Davidson, E. M., Sandøe, P., & Kristensen, H. H. . Behavioural consequences of visual deprivation occurring at hatch or in the early life of chickens Behavioural consequences of visual deprivation occurring at hatch or in the early life of chickens (2015)
- Hocking, P. M., & Guggenheim, J. A. The chick as an animal model of eye disease Drug Discovery Today: Disease Models (2014)
- Cecchinato, M., et al.. An Outbreak of Blindness Due to Retinopathy in Nine Flocks of Guinea Fowl Avian diseases (2014)
- E Chase. What a Blind Chicken Can Teach Us About Humanity The New York Times (2013)
- Singh SD, Barathidasan R, Kumar A, Deb R, Verma AK, Dhama K.. Recent trends in diagnosis and control of Marek's disease (MD) in poultry. Pak J Biol Sci. (2012)
- Boote C, Elsheikh A, Kassem W, Kamma-Lorger CS, Hocking PM, White N, Inglehearn CF, Ali M, Meek KM.. The influence of lamellar orientation on corneal material behavior: biomechanical and structural changes in an avian corneal disorder. Invest Ophthalmol Vis Sci (2011)
- K Bartlett. Scientists Restore Sight To Chickens With Blinding Disease University of Florida (2006)
- C.F. Inglehearn; M.D. Mohamed; L.M. Downey; I.G. Simmons; C. Thaung; L.R. Bridges; G.W. Roberston; D.H. Lester; D.W. Burt; P.M. Hocking. Blindness Enlarged Globe (beg), a recessively inherited mutation in chickens Investigative Ophthalmology & Visual Science (2004)
- Shivaprasad HL, Korbel R.. Blindness due to retinal dysplasia in broiler chicks. Avian Dis (2003)
- Inglehearn CF, Morrice DR, Lester DH, Robertson GW, Mohamed MD, Simmons I, Downey LM, Thaung C, Bridges LR, Paton IR, Smith J, Petersen-Jones S, Hocking PM, Burt DW.. Genetic, ophthalmic, morphometric and histopathological analysis of the Retinopathy Globe Enlarged (rge) chicken. Mol Vis (2003)
- Akan M, Haziroğlu R, Ilhan Z, Sareyyüpoğlu B, Tunca R.. A case of aspergillosis in a broiler breeder flock. Avian Dis (2002)
- Salter DW, Payne WS, Ramsey DT, Blair M, Render JA.. A new inherited ocular anomaly in pigmented white Leghorn chickens. J Vet Diagn Invest. (1997)
