Conjunctivitis is a general term which refers to an inflammation and swelling of the conjunctiva, the delicate membrane that lines the eyelids and covers the exposed surface of the eyeball. In house finches, the infection is attributed to Mycoplasma gallisepticum, a microorganism which typically causes respiratory illnesses in domestic poultry. The disease is not contagious to humans, dogs, or cats. Reports of affected birds have been limited almost entirely to house finches, although there have been a few confirmed reports in other species, most notably goldfinches.
House finch (pictured right) conjunctivitis was first documented in February 1994 in Washington, D.C. Since then, it has moved westward, through the eastern United States, crossing the Mississippi River and infecting house finches as far west as Texas.
Most individuals report seeing only one or two affected house finches at a time although some say that a large percentage of house finches visiting their feeders show signs of the infection.
Wildlife disease researchers continue to study this infection. While house finches with swollen eyes may be infected with Mycoplasma gallisepticum, there are several other causes of conjunctivitis in birds, such as injuries, bacteria, fungi, nematodes, and protozoa. The symptoms of conjunctivitis caused by MG are typically more severe than those caused by other factors. Research has shown that house finches are particularly susceptible to this infection.
House finches are now a common breeding bird in urban areas throughout the state and a familiar visitor at bird feeders where they consume Niger thistle, sunflower, and other seeds.
The Division will respond to inquiries about infected house finches, but is particularly interested in hearing about any occurrence of conjunctivitis in other species of birds.
People who feed birds have the best opportunity to see such infections because the birds are easy to view at feeding stations. The Division would like to know what species is involved and the date and county where it was observed.
The Division of Wildlife is also requesting reports of cardinals with missing head feathers. "These birds look bizarre," says Peters. "Without the contour feathers, the head appears very small and dark gray in contrast to the brighter body. We received our first report of this condition two years ago and they are coming more frequently."
Editors Note: Please direct all reports and inquiries to (614) 265-1015. Reports may also be mailed to Division of Wildlife-Conjunctivitis, 2045 Morse Road, Columbus, 43229-6693.
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