Few signs of deadly bird infection, but expert says be cautious when hanging feeder

Bird enthusiasts who took down their feeders last year because of an infectious bird disease known as trichomoniasis may be able to hang them back up this year — but they should be on the look out for birds with signs of the disease. 

Megan Jones, wildlife pathologist and the Atlantic regional director of the Canadian Wildlife Health Cooperative (CWHC), said the feeders should be taken down for the whole season if there are signs that birds in the area may have trichomoniasis, but she said there haven't been any lab-confirmed cases of the disease in the Maritimes yet. 

But Jones said just because there have been no confirmed cases, doesn't mean the disease isn't going to occur at all this year, especially since it's early in the season.

"If you've seen sick birds at your feeder that you think could be trichomoniasis, we would recommend you take them down," she told Information Morning Fredericton.

There have been four suspect cases reported to CWHC in the Maritimes so far this year. Suspect cases are those that are reported to CWHC by the general public, but no specimen is submitted for laboratory examination. There have only been two suspect reports of trichomonosis in New Brunswick, one in the Saint John area and one in the Doaktown area. 

How it spreads

Trichomoniasis mainly affects seed-eating birds, like American goldfinches and purple finches, in Atlantic Canada. It poses no danger to humans or mammals.

A microscopic parasite (Trichomonas gallinae) causes trichomoniasis, which is an infection in the mouth and throats of birds that makes them unable to swallow. Because of their inability to swallow, birds may have wet or ruffled feathers and food particles around their face or beak.  

Bird feeders and baths are potential sites for transmission for trichomoniasis.

107 cases were reported to the CWHC from the Atlantic provinces in 2017. Of those, 18 were lab-confirmed cases. 

The first case of trichomoniasis in Atlantic Canada was reported in 2007 and, according to Jones, they've seen cases "pretty much every year since then."  

"It's been known for a long time, [but] what was weird about 2007 was that it showed up in finches as causing a really significant disease and causing mortalities," Jones said.  

The disease had not been identified as a cause of illness or death in native finches before 2007, although it had existed for a long time in other species, like pigeons and raptors.

Keep bird feeders clean

Jones said the parasite that causes the disease can survive in moist bird seed for prolonged periods of time.

"We know that bird feeders are a place where birds congregate, and so sick birds could pass it in their droppings or in their regurgitation," she said.

If the disease has been confirmed in a particular area, she recommends that people take down their bird feeders until the first cold frost of the fall.

However, there are measures people can take to make their bird feeders safer, including keeping their bird feeders clean by washing it with soap and water.

"We know the parasite can survive in moist bird seed, but if your seed is dry and clean, it doesn't survive very long," she said.

Rubber gloves should be worn when cleaning bird feeders and any equipment used to clean them should not be used for other purposes, as birds can carry other diseases that humans are susceptible to.

Any sick or dead birds should be reported to the CWHC.