 Bird Diseases
House Finch Disease
Avian Pox
Salmonellosis
Aspergillosis
Trichomoniasis
What do I do if I see a
sick bird?
Most people go for years without
seeing a sick bird. Below we describe five common avian diseases that you should be aware
of in case you are unfortunate enough to have a sick feeder bird. Remember, prevention is
the key to avoiding disease: regularly clean your feeding station.
House Finch Disease
House Finch Disease was first
noticed in 1994 by a handful of FeederWatchers in the Washington D. C. area. Birds
infected with this disease (also called mycoplasmal conjunctivitis) appear to have red,
swollen, runny, or crusty eyes; in extreme cases the eyes become swollen shut or crusted
over, and the bird becomes blind and unable to fend for itself. You might observe an
infected bird sitting quietly in your yard, clumsily scratching an eye against its foot or
a tree. While some infected birds recover, many die from starvation, exposure, or
predation.
Conjunctivitis can have many
causes, but the type most often seen in House Finches is caused by the bacterium Mycoplasma
gallisepticum. This bacterium has long been known as a pathogen of domestic turkeys
and chickens, but has been observed in House Finches only since 1994. More recent reports
indicate that it also has spread to the American Goldfinch. As birds flock together at
feeders, transmission of the disease becomes more likely.
You can help us monitor the spread
of this disease by contributing to the House Finch and American Goldfinch Disease Survey.
For more information, visit http://birds.cornell.edu/hofi/index.html or call (800) 843-2473.
TOP OF PAGE
Avian Pox
There are two forms of avian pox.
In the more common form, wart-like growths appear on the featherless areas of the body
such as around the eye, the base of the beak, and on the legs and feet. In the second
form, plaques develop on the mucous membrane of the mouth, throat, trachea, and lungs,
resulting in impaired breathing and difficulty in feeding. Secondary infections often
develop and ultimately lead to an infected bird’s death.
Avian pox can be caused by several
strains of Poxvirus, and has been reported in at least 60 species of birds from 20
families, such as turkeys, hawks, owls, and sparrows. The virus can be spread by direct
contact with infected birds or contaminated surfaces (e.g., feeders), or by ingestion of
contaminated food or water.
TOP OF PAGE
Salmonellosis
Salmonellosis is caused by a
bacteria belonging to the genus Salmonella. It is a common cause of mortality in
feeder birds, but the symptoms are not always obvious. Sick birds may appear thin, fluffed
up, and depressed and may have pasted vents and swollen eyelids. They are often lethargic
and easy to approach. Some infected birds may show no outward signs, but are carriers of
the disease and can spread the infection to other birds.
Salmonellosis is primarily
transmitted by fecal contamination of food and water by birds, though it can also be
transmitted by ingestion of contaminated feeds or from bird-to-bird contact. Occasionally,
outbreaks of the disease cause significant mortality in certain species.
TOP OF PAGE
Aspergillosis
Aspergillosus is a fungal disease
that affects the respiratory system of birds. Healthy birds normally resist the disease,
but birds with depressed immune systems are especially vulnerable. External symptoms
include difficulty in breathing, emaciation, and increased thirst. Birds also can appear
to have difficulty walking. When their eyes are infected, there may be a white opacity in
one or both eyes, accompanied by a discharge.
Aspergillosis is a mold infection
that is usually caused by Aspergillosus fumigatus, commonly found in decaying
vegetable matter. A bird becomes infected by the ingestion or inhalation of mold spores
from contaminated foods. The infection causes lesions in the lungs and air sacs and has
been reported in many species of birds. Occasionally, outbreaks of the disease cause
significant mortality in certain species.
TOP OF PAGE
Trichomoniasis
Trichomoniasis is a disease that
most commonly affects pigeons, doves, and the raptors that feed on them. It is
characterized by raised lesions in the mouth, esophagus, and crop. Infected birds may
appear to have trouble closing their mouth. The disease is caused by the protozoan Trichomonas
gallinae, which is often present in the mouth secretions of birds that appear to be
healthy but are carriers of the disease, such as pigeons.
Infected birds can contaminate
water containers (bird baths) with their oral secretions, which can, in turn, expose many
other birds to the disease. Mortality from this disease varies, but it can be quite high.
TOP OF PAGE
What do I do if I see a sick bird?
Only veterinarians or federally
licensed wildlife rehabilitators can legally treat wild birds. Therefore, if you find a
diseased bird, it’s best to report it to your state or local wildlife agency. If you
are advised to take the bird in for an examination, try to catch the bird by throwing a
light towel over it and placing it in a box with airholes. If you find a dead bird, place
it in a double plastic bag and into the garbage (wear gloves).
If a sick bird comes to your
feeder, minimize the risk of infecting other birds by cleaning your feeder area
thoroughly. If you see several diseased birds, take down all your feeders for at least a
week to give the birds a chance to disperse. Keep the feeders down until you no longer see
diseased individuals. And remember that prevention is the key to avoiding the spread of
disease. Regularly clean your feeders even when there are no signs of disease and prevent
overcrowding by adding more feeders or setting up different types of feeders that allow
only a few birds to visit at one time.
To report sick birds and to learn
more about these diseases contact the National Wildlife Health Center.
TOP OF PAGE
|
GET STARTED 