Watch this report by Penny Silvester:
Interviewees: Joanne De Nobriga, Swan Support volunteer & Wendy Hermon, Swan Support co-ordinator
The number of swans being attacked by dogs is on the rise in Berkshire, according to a wildlife rescue centre.
Swan Support says it is a particular problem during the nesting season, from February until August, where birds are more vulnerable.
It is calling for dog owners to keep their animals on leads.
A volunteer at the charity recently witnessed a horrifying dog attack beside the Kennet and Avon canal.
The female swan was badly bitten and unable to walk, but is now being nursed back to health.
Dog owners are being urged to keep their pets on leads unless they are well away from wildlife.
We've been doing this for over 25 years and this year has been the worst year ever for dog attacks especially on nesting females. We're not anti-dogs. I take my dogs out on a lead. I let them off the lead in an open area, in a field or park. But when there's wildlife, it's just common sense to put your dog on the lead."