Most Common Bird Diseases
If you have a bird feeder in your backyard you can enjoy an up-close view of the birds. At the same time you can easily spot a sick bird at your feeder. When the bird is sick it looks for easy meals and often comes to feeders placed by man. It should be noted that only veterinarians or federally licensed wildlife rehabilitators can legally treat wild birds. If you see a bird that seems to be sick or injured never attempt to treat the bird yourself. Keeping wild birds at home is against the law unless you act under the supervision of a licensed specialist.
If you noticed a sick bird near your feeder, do everything possible to reduce the risk of other birds catching the disease to minimum. First of all, clean the whole feeder area thoroughly. In case you spotted several sick birds, take down all your feeders for a week or two so the birds could disperse. Remember that it's easier to prevent the diseases than treat it. Make sure you clean your feeders often even when there are no signs of disease.
House Finch Eye Disease
Birds suffering from House Finch eye disease (or Mycoplasmal conjunctivitis) have red, swollen, runny, or crusty eyes. Sometimes the eyes may get swollen shut and the bird can even get blind. This bird disease is caused by Mycoplasma gallisepticum bacterium that is considered a pathogen of domestic turkeys and chickens, but also has been infecting House Finches since 1994. Some other bird species like American Goldfinch, Purple Finch and Evening Grosbeak also have high chances of catching the disease.
Avian Pox
There are two forms of avian pox. The symptoms of the common form are wart-like growths on the areas of the body free from feathers – legs, feet, around the eyes or the base of the bill. In the second case, plaques appear on the mucous membrane of the mouth, throat, trachea, and lungs, making it hard for the bird to breathe and feed. Both forms of the disease are caused by some strains of the pox virus. More than 60 species of birds, including turkeys, hawks, owls, and sparrows are known to get infected by it. The virus is spread through direct contact with infected birds or contaminated surfaces (feeders, for example) or by consuming contaminated food or water.
Salmonellosis
This disease is caused by one of Salmonella bacteria. In some cases infected birds become thin or fat, often fluffed up and with swollen eyelids. The birds also may become lethargic so they are easy to approach. Sometimes the symptoms of this mortal disease are hard to notice and the carriers of the bacterium continue to infect other birds. Sick birds transmit salmonellosis through fecal contamination of food and water, or bird-to-bird contact. There have been instances when severe outbreaks of the disease resulted in high mortality rate of some species, such as Pine Siskin, Common Redpoll, and American Goldfinch.