Disease among garden birds
3 September 2013
From time to time, sick or dead birds may appear in a garden. Unfortunately, once birds are visibly sick it is rarely possible to treat them successfully.
The best thing people can do is to prevent healthy birds from catching the infection, thereby helping to slow down or stop the spread of disease.
Exercise good hygiene around the feeders and water containers, and if necessary, withdraw food to encourage birds to disperse to feed over a wider area. It is better to do this than to expose them to a serious disease risk.
If you must handle sick or dead birds, it is important to exercise great care and hygiene, since there is a small but real risk of transmissible infections from sick birds. Some of the diseases of wild birds, most notably salmonella and coliform infections, can be passed onto people and pets.
Use protective gloves, and wash hands and forearms thoroughly as soon as you have finished with the bird. Avoid touching your eyes, nose or mouth until you have been able to wash properly. Do not allow your pets to play with or eat birds, especially if they are sick or dead.
Please see our page on hygiene precautions (right) for more details.
Can sick birds be treated?
No treatment can be administered to birds in the wild, because it is impossible to ensure adequate dose for the infected individuals and to prevent healthy birds picking up the medicine. Some drugs that will cure one species can be lethal to others.
Once birds are visibly sick and can be caught, they are usually so sick that they cannot be treated successfully. You may wish to contact a local vet or RSPCA inspector, since the kindest thing may be to put these birds to sleep. While many vets are happy to treat wild birds without a charge, check on this before taking the bird to a vet. Please note that the RSPB is a conservation charity. We do not run bird hospitals or a rescue service, and so are unable to help a sick bird.
Trichomonas gallinae affects bird's digestive system. It typically affects finches, and doves and pigeons. Any bird can catch the infection, but being bird specific, it does not pass on to mammals, including humans.
Trichomonosis causes lesions in the throat of the infected bird, which makes it progressively harder for the bird to swallow its food. In addition to showing signs of general illness such as lethargy and fluffed-up plumage, affected birds may regurgitate food, have difficulty swallowing or show laboured breathing. Finches frequently have matted wet plumage around the face and beak, and uneaten food in and around the beak. Sometimes it is possible to see swelling in the throat area of an infected bird and it may stretch its neck in discomfort.
The infection is spread as birds feed one another with regurgitated food during the breeding season, and through food and drinking water contaminated with freshly regurgitated saliva. Sick birds, unable to swallow, will spit out food particles, which then carry the infection. Trichomonas is vulnerable to desiccation and cannot survive for long periods in the open outside a bird.
The higher the concentration of birds at a feeding station, the greater the chance of another bird exposing itself to the infection.
If a number of birds show symptoms of trichomonosis, it is recommended to temporarily stop putting out food, and leave bird baths dry until no further sick or dead birds are found in the garden. This will help to disperse the feeding birds and reduce contact between sick and healthy individuals, thus slowing down or halting the outbreak.
Avian pox is a viral skin infection that shows up as warty growths on the head (particularly next to the eyes and beak), legs, wings or other body parts of the infected bird. The growths are usually grey, pinkish, red or yellow in colour, and can reach a considerable size. Smaller brown or grey lesions can be confused with ticks. Affected birds feed and move around normally. The birds most often affected are tits, dunnocks and pigeons.
Avian poxvirus spreads between birds by biting insects, by direct bird-to-bird contact, and by indirect contact via contaminated surfaces such as perches or bird feeders. The virus is relatively resistant and can persist on contaminated surfaces for long periods of time.
Where an avian poxvirus outbreak exists, ensure optimal hygiene at garden bird feeding stations, paying particular attention to regular disinfection of surfaces that the affected birds have been in contact with, such as perches or feeder ports. Clean out bird baths on a daily basis, and refill with fresh water. If a large number of affected birds congregate, consider reducing the amount you feed while affected birds visit the garden to help reduce close contact between them and healthy birds.
Salmonellosis is a bacterial infection, which is present at a low level in wild bird populations. Salmonella outbreaks can be seen in wild birds in Britain during the winter months. Flocking ground feeders, such as greenfinches and house sparrows, are most commonly affected. There are no symptoms specific to salmonella, but infected birds will show general signs of ill-health. They are listless and lethargic, tend to stay close to feeders, fail to respond to danger and can be approached closely. Even though an infected bird tends to continue to eat almost to the end, it will become weak and emaciated.
As this infection is spread through droppings (when they contaminate items eaten by other birds) ensuring good hygiene at feeding stations is the best way to avoid it spreading.
Some types of Salmonella are responsible for food poisoning in people. Therefore, it is very important to exercise good personal hygiene if handling sick or dead birds, and when cleaning the feeders and water containers.
Some other infections
There is a range of other bacterial, viral and parasitic infections that are encountered from time to time in garden birds.
Coliform infections can occur in garden birds. While some of these bacteria occur normally in the intestine, outbreaks in finches are normally caused by Escherichia albertii. The affected birds show general signs of ill-health – lethargy and fluffed-up plumage. Although these infections can occur any time of the year, they seem to be more common in the late spring months. Outbreaks are best prevented by keeping all feeding areas and water containers clean and free from droppings.
Foot deformities in finches are normally caused either by chaffinch viral papilloma or by burrowing mites that cause cnemidocoptiasis. Both of these show up as pale, crusty growths on the feet of the affected bird. Neither condition is life-threatening, although they can cause visible discomfort.
Chlamydiosis, also called psittacosis or ornithosis is a well-known infection in pet parrots, but can also affect wild birds such as pigeons. There are rare instances where it has also been affecting birds such as robins, dunnocks and tits.
Gape worm is a throat parasite found in blackbirds and other earthworm eaters. It moves from an earthworm to a bird and back to an earthworm.