Cleaning bird feeders, trichomonosis and bird flu

Feeders and bird baths are where the BTO says disease is most likely to spread in a garden, because sick birds leave saliva or droppings on food and water that other birds use. Cleaning does not remove every risk. The RSPB’s October 2026 explainer says the trichomonosis parasite was found on food in feeders, on trays and on the ground, and not on the feeder surfaces in that study (none of 79 feeders). Regular cleaning is still what both organisations ask for. It is not, on its own, enough.

Once a week, if you are feeding

The RSPB says clean feeders and bird baths at least once a week. The BTO gives weekly as the example. A routine that matches both pages:

1. Take the feeder down and throw away the old food. Do not pour it under the hedge. The BTO says dispose of it as waste, where wildlife cannot still eat it.
2. The BTO says dampen surfaces first so you are not breathing dry dust, and wash dirt off before disinfectant. Dirt neutralises the disinfectant.
3. Wash with hot soapy water. The RSPB then says disinfect with a non-toxic product such as Ark-Klens, or a mild (5%) bleach solution. The BTO says a weak solution of domestic bleach (5% sodium hypochlorite), or a commercial product diluted as the bottle says. Those phrases are not identical. Use the bottle’s own dilution. Do not mix a stronger solution because two pages both mention 5%.
4. Rinse with fresh water and let the parts air-dry before you refill.
5. Clear waste and droppings from underneath. If the lawn makes that awkward, the BTO says moving the feeder even a short distance stops the pile growing.
6. The RSPB asks for a different spot every week where you can, and for separate areas if you have more than one feeder.

Brushes for feeders stay outside and are not used for anything else. Wear rubber or disposable gloves. Wash your hands and forearms with soap and water afterwards, especially before you eat. The BTO is explicit that some bird diseases can affect people, and that the risk is small but worth the gloves.

Do not clean feeder parts in the kitchen sink.

Food and water, not just the plastic

The BTO says provide fresh food from a reputable source, in amounts you will use, stored sealed, cool and dry, so condensation does not encourage mould. Remove uneaten food after 24 to 48 hours and do not refill on top of old food.

Water can carry the trichomonosis parasite. The RSPB says change it daily, and only offer it if you will do that. More is in water for garden birds.

If you see a sick bird

The signs the BTO gives for trichomonosis are difficulty swallowing, laboured breathing, and swelling of the throat and neck. For avian influenza they list a swollen head, watery droppings and neurological signs. Their disease page says avian influenza since the winter of 2021/22 has hit wildfowl, seabirds and birds of prey hard. It is not described there as a typical garden-finch disease. Garden birds that look ill should still make you stop feeding.

Here the two organisations do not match, and both pages were open on 14 November 2026:

• The BTO says stop feeding for at least two weeks since you last saw an unwell bird, especially if several birds are sick or dead, so that birds disperse. Empty the bird bath until you see no further sick or dead birds. Start again only when you are no longer seeing signs, and stop again if they return.
• The RSPB feeding page says if you see a sick bird on your feeders, stop feeding altogether, clean thoroughly, and store the feeders away (a garage or shed). Resume only after a month, and only if no more sick birds are seen.

We are not choosing a winner. If you want a single rule, follow the page you trust and re-read it, because both organisations say the advice can change. Reporting is separate: the BTO asks for sick or dead garden wildlife to go to Garden Wildlife Health. Dead wild birds and what GOV.UK says about disposal are in sick and dead birds.

Treatment is rarely useful, the BTO says. By the time a bird can be caught it is often too ill, and medicine scattered in a garden will not reach only the sick bird at the right dose. A bird that can still escape a cat may be better left. If you are worried about welfare, they suggest a local vet, the RSPCA in England and Wales, or the Scottish SPCA.

What cleaning cannot fix

The seasonal pause on seeds and peanuts, from May to October, exists because cleaning alone has not stopped finch trichomonosis. The BTO links the disease to declines in greenfinch and chaffinch survival, more sharply in residential places, which fits transmission at feeders. The RSPB says greenfinches have dropped by 65% in the last three decades, and that in the 2026 Big Garden Birdwatch they ranked 18th, against 7th when the survey started in 1979. Those are their figures, from their page.

How often should I clean a feeder?

At least weekly while it is in use, according to the RSPB. The BTO uses weekly as the worked example. Clean sooner if the food is wet or caked.

Bleach or a wildlife disinfectant?

Either, as those pages describe them. Follow the dilution on the bottle, rinse, and dry. Keep the brush outside.

The RSPB says a month and the BTO says two weeks. Which do I follow?

Both are published. This site will not pretend they are the same. Stopping at once is the shared part. Read the current page before you put feeders back.