The inability to waterproof itself by a swan is a sign that something is definitely wrong. Swans can not only drown, but get chilled and develop a cold, pneumonia or other serious illness. You did the right thing by bringing her inside and warming her. She needs to be checked by a veterinarian (Blood test) to ensure she is not suffering from any illness which might require an antibiotic. In the meantime, she needs to stay warm. If you can give her a warm bath in Dawn Dish Soap (not sure what your brand name is in Australia-you may need to check with a waterfowl rescue facility to find out what soap product they use for de-oiling seabirds/waterfowl. Bathe the swan in the soap and warm water. Remove the algae by scrubbing the feathers (something is causing the feathers to retain the algae). Rinse with warm water and place the swan in a warm room, gently towel and blow dry almost to the point of totally dry. Leave some moisture on the feathers and allow the swan to preen herself dry so that she can re-oil her feathers with the uropygial oil from her preen gland.

Keep her slightly misted for two days so that she can continue to use the preen oil. Keep her on antibiotics if determined by the veterinarian. Once she is off the antibiotics, bathe her one more time. Allow her to completely dry herself and observe the condition of the feathers. Then, mist her with warm water the next day and again observe the condition of the feathers.

If everything looks good, then you can release her back into the pond, with a boat ready or other means to capture her in the event that her feathers are still not working. If she cannot maintain water repellency, you will need to keep her in a pen with a small water feature where she cannot drown, cannot be accessed by predators and allow to live until the problem can be rectified. If this is a permanent problem, she will need to live in a very controlled setting. However, having said this, usually antibiotics and a good bath usually takes care of the problem. Please let us know how she is doing. The Regal Swan