Oh Stu, I know what you mean. We have a cat which visits our front and/or back gardens on a daily basis and I have the joy of collecting up its deposits. Apart from the awful smell, it's a horrible job.
I wonder if it's owner ever wonders or cares where it poos?
Strange how folks moan about dog poo (quite rightly) but cats seem to be blameless!
PS I hope the dog owner recognised himself and will think twice next time.