when i take my greyhound out for a walk

[lindseykay]

when i take my greyhound shergar out for a walk with my border collie every time he sees a dog or cat no matter what size they are he just goes mad and barks at them and tries to attack them we can hardly take them out what can we do to help

[kita1]

This link may help:

http://www.ttlntl.co.uk/3/BehAdv/agress.htm

does it only happen when you take the two dogs out together? Or does he do it if you take him out on his own?