Parasitic infection kills finches
Trichomonas gallinae is a protozoan that lives in the throats and crops of birds. In Finland it has been previously found in domestic pigeons. When birds of prey eat infected birds, the disease can be transmitted to them and make them seriously ill. In small birds the parasite causes a painful infection in the upper digestive tract and in the crop, which makes it difficult for the birds to eat so that eventually they famish. Infected birds appear fluffy and lethargic and may have secretion on their beaks. The parasite is not transmitted to humans, or to e.g. dogs and cats.
The Trichomonas parasite causes an infection called trichomonas, which has been found in small birds since 2005 in England, where it causes mortality of chaffinches and greenfinches that visit bird feeders in gardens. This year the infection was found for the first time in finches in Sweden and Norway. In Finland, reports of infected birds have been received in September and October from Kaarina, Halikko and Turku in south-western Finland. Most of the infected birds have been greenfinches.
Trichomonas is transmitted among the birds through secretion from the beak. At bird feeders, for example, sick birds may contaminate the seeds and the peels of the seeds or the drinking water with this secretion. The parasite does not survive in temperatures below zero, which is why outbreaks of the disease usually occur during the mild seasons. Drought also kills the parasite. Birds should usually only be fed in the winter to prevent parasitic infections. If birds suffering from trichomonas or showing the symptoms of the infection are seen at feeders, the feeders have to be thoroughly cleaned. Bird baths must also be emptied and cleaned, and preferably also disinfected. Any feed that has fallen on the ground should be removed. The feeders should be moved to a new place or at least feeding should be discontinued until the temperature falls below zero.
Evira continues to monitor the occurrence and possible spreading of the Trichomonas parasite. Samples and reports of dead small birds can be sent to Evira's Fish and Game Health Research Unit, which can be contacted by telephone or e-mail.
For more information, please contact:
Marja Isomursu, Researcher (veterinarian), tel. +358 (0) 20 77 24910, e-mail: marja.isomursu evira.fi