Trichomoniasis: disease risk to finches, sparrows and some other garden birds
Over the past few years, BirdWatch Ireland has periodically received reports of birds suffering from a disease known as Trichomoniasis (also sometimes called Trichomonas). Since about 2009 reports of infected birds remained at a steady but low level. However, the past couple of months have seen a renewed increase in the reports of birds suffering from this disease, with Greenfinches being the hardest hit.
Trichomoniasis occurs as a result of infection with the single-celled protozoan Trichomonas gallinae. The infection causes the growth of lesions at the back of the throat, as well as the sinuses of the bird. Over time, these growths restrict or even block the throat, making it difficult or even impossible for a bird to drink or eat. If the growths reach the latter stage, it is usually fatal to the bird – mainly as a result of dehydration or starvation. However, it is not fatal in all cases and some birds may recover.
There is currently no cure available for wild birds infected with Trichomoniasis. Birds suffering from the disease, especially in severe cases, appear lethargic and will sit in one spot for long periods. They may also have fluffed-up plumage, as well as wet and matted plumage around the beak. However, during cold weather many birds fluff-up their plumage to preserve heat, so this alone is not a definite sign of sickness.
Greenfinch showing signs of Trichomoniasis: note its ragged
appearance and the matted feathers on its face
(Photo: Cóilín MacLochlainn)
Most reports in Ireland of birds sick with Trichomoniasis have been of Greenfinches and, to a lesser extent, Chaffinches. Other species in which the disease has been noted include other members of the finch family, House and Tree Sparrows, Collared Doves, Pheasants and some birds of prey. However, many garden birds, such as Robins and Blackbirds, appear to be unaffected by the disease; it is also harmless to humans, and indeed all mammals.
To prevent the spread of Trichomoniasis, the best advice is to regularly clean bird feeders and baths, and to let them air dry, as the protozoan responsible for the disease survives for only a short time away from moist conditions. It can be helpful to use a wildlife-friendly biological disinfectant on feeders and baths: a recommended brand is available from the BirdWatch Ireland online shop.
If possible, bird feeders should be moved occasionally to prevent the build up of waste which may harbour the disease. If a bird suffering from Trichomoniasis is noted, all feeding should be stopped, with bird feeders and baths cleaned and air dried. Feeding should be stopped for approx. 10 days to two weeks to allow birds which had previously visiting the feeders to disperse and so reduce the likelihood of other birds being infected. However, it is best not to resume until you no longer see any infected birds in or around your garden.
Greenfinch with Trichomoniasis: note the bedraggled, wet appearance
of the feathers around its face
(Photo: Cóilín MacLochlainn)
If you have seen any birds likely to have been infected with Trichomoniasis or would like more information about the disease, you can contact BirdWatch Ireland by phone at 01 2819878 or by email at firstname.lastname@example.org.