A killer disease that is ravaging Britain's small garden birds has spread to Norfolk for the first time. Common birds such as finches, sparrows and blackbirds are starving to death as a result of a parasite that swells their throats, preventing them from eating.

A killer disease that is ravaging Britain's small garden birds has spread to Norfolk for the first time.

Common birds such as finches, sparrows and blackbirds are starving to death as a result of a parasite that swells their throats, preventing them from eating.

Bird lovers are being warned to disinfect their feeders and bird baths regularly, and in more extreme circumstances stop feeding birds altogether, to help prevent the spread of the infection.

The parasite, trichomonas gallinae, has been common among pigeons and game birds for a number of years and is treatable with drugs in captive animals.

But, in a development which has baffled scientists, it has suddenly spread to small wild bird species, which, because they fly freely cannot be helped by medicine.

Experts are also unable to put a figure on how many birds have already died since the problem was first identified in parts of the north and south of England in 2005.

The disease is most prevalent in late summer and early autumn. Last year birds in East Anglia seemed to have largely escaped the infection. But this year reports of diseased birds in the region are already flooding in, with numerous reports in Norfolk for the first time.

Graham Appleton, from the British Trust for Ornithology, said the spread of the disease was currently being researched and the reason why wild birds had suddenly become susceptible was under investigation, but as yet no answers were available.

He said: “In pigeons the disease is called canker and has been known for years, but recently it has started to be seen in the wild bird population.

“It has been spotted in quite a few species - most commonly the greenfinch, but it is also affecting chaffinch, the sparrow, blackbirds and probably starlings. The disease has spread each year and has spread into Norfolk this year.”

The parasite is passed on through saliva and bird droppings. It can also be passed on by birds regurgitating food for their young during breeding season.

Often birds with the disease show signs of lethargy and will not fly away when approached. They may also suffer from fluffed-up plumage, drool and regurgitate food, and have laboured breathing.

Humans and household pets such as cats and dogs are not affected by the parasite.

One bird enthusiast in Norfolk is already taking direct action. Bill Drayton, from Brewery Road, Trunch, near North Walsham, has written to all the homes in his area asking people to decontaminate their bird feeders and baths and to stop feeding the birds.

He said: “I do not want to panic people, but I also don't want people to put the birds at more risk.

“I have found several birds dead in my garden in the last few weeks.”

Kirsi Peck, RSPB wildlife advisor, said it was impossible to put a figure on how many birds had been affected either nationally or regionally.

She said: “Although we do get reports from people, each bird would need a post mortem to confirm the disease.

“Another complication is we do not know how many go unreported. There is just no way to put a figure on it.

“There were very few cases reported in the eastern region last year but there are more this year.”

t The RSPB is part of a scheme called The Garden Bird Health Initiative, which studies garden bird health and disease outbreaks. It is appealing for anyone who finds sick or dead birds in their garden to get in touch so it can monitor the spread and intensity of disease outbreaks. Go to www.rspb.org.uk/advice/helpingbirds/health/sickbirds/greenfinches.asp and click on the downloadable registration form or call 0207 449 6685.

t For information or advice email wildlife@rspb.org.uk or call 01767 693690.

TRICHOMONIASIS: THE FACTS

Trichomoniasis typically affects pigeons and doves in the UK. It can also affect birds of prey that feed on pigeons and doves that are sick with the condition.

The common name for the disease in pigeons and doves is “canker” and in birds of prey the disease is known as “frounce”.

Infested birds show signs of illness such as lethargy and fluffed-up plumage. They may also drool saliva, regurgitate food and have difficulty swallowing. Finches are frequently seen to have matted wet plumage around the face and beak.

The disease is spread through food or drinking water contaminated with recently regurgitated saliva, or possibly, from droppings of an infected bird.

The parasite does not pose a health threat to humans or mammals such as dogs and cats but does have the potential to affect captive poultry and pet birds.

Helping stop spread of disease on your bird table:

t Clean and disinfect feeders and feeding sites regularly. Suitable disinfectants that can be used include a weak solution of domestic bleach. Always rinse thoroughly and air-dry feeders before re-use.

t Do not use brushes and cleaning equipment used for bird feeders, tables and baths for any other purpose and store safely.

t Wear rubbers gloves when cleaning feeders and thoroughly wash hands and forearms afterwards with soap and water.

t Avoid handling sick or dead birds directly.

t Where a problem with trichomoniasis exists consider leaving bird baths empty until no deaths occur.

t Where large numbers of birds are sick or dying, consider significantly reducing or stopping feeding for a short period. This will encourage birds to disperse and minimise the chance of new birds becoming infected.