TrichomoniasisWe have had lots of reports from our members of sick and/or dying birds frequenting their bird table and feeding stations. This is almost certainly due to the parasite Trichomoniasis which has been very prevalent in finches throughout the Waveney Valley this last autumn. It mostly affected Greenfinches and Goldfinches and is nearly always witnessed close to permanent feeding stations. WBC ringers have found many underweight individuals, for example Greenfinches < 24g and Goldfinches < 12g. These were signs that birds were hosting the parasite and was confirmed by a quick check on the pectoral muscles and mucous deposits around the. WBC ringers do not ring infected birds generally to avoid a waste of rings – infected birds are going nowhere! However, some believe that if we don't ring and record such birds, then we will be unable to determine whether there is any sort of recovery percentage! This debate continues. The RSPB website reports that the trichomonad parasite lives in the upper digestive tract of the bird, and its actions progressively block the bird’s throat making it unable to swallow food, thus killing it by starvation. Birds with the disease show signs of general illness, for example lethargy and fluffed-up plumage, but affected birds may also drool saliva, regurgitate food, have difficulty in swallowing or show laboured breathing. Finches are frequently seen to have matted wet plumage around the face and beak. In some cases, swelling of the neck may be visible from a distance. The Trichomonad parasite is vulnerable to desiccation (drying out) and cannot survive for long periods outside the host. Transmission of infection between birds happens when they feed one another with regurgitated food during the breeding season and through food or drinking water contaminated with recently regurgitated saliva, or possibly from droppings of an infected bird. To minimise parasite transfer the general advice is to stop feeding for 14 days and increase hygiene precautions by scrubbing bird tables with disinfectant, provide clean water only if it can be changed several times a day, empty birdbaths, etc. Feeding can continue once there are no sick or dead birds in the garden. There is no effective treatment can be administered to birds in the wild, because it is impossible to ensure that the infected individuals receive an adequate dose and that healthy birds do not pick up the medicine. Ringers should ensure that bird bags are clean and any throught to have been used to carry an infected bird should be removed from circulation for washing. Weighing cones should be cleaned after each bird is processed. The Garden Bird Health initiative was set up as a UFAW (Universities Fund for Animal Welfare) Working Group in 2003, including among others the RSPB, the BTO, and the Institute of Zoology. Dead birds could be sent to the Institute of Zoology for analysis. I do have one further dilemma. One of the sites where infected birds have been seen also hosts one of Suffolk's last Tree Sparrow colonies. If feeding is stopped, the Tree Sparrows will probably disappear! I have House Sparrows feeding alongside infected Greenfinches in my garden but have yet to find one with signs of the parasite. I would be interested to hear from anyone who has found either Tree Sparrows or House Sparrows showing symptoms of "Tricho"? For further information visit: www.ufaw.org.uk/gbhi.php or see the attached information sheets. Steve Piotrowski |
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