A friend has a small young cat who unfortunatley repeatedly gets attack by another in the neighbouirhood. This attacks are very serious and the agressor has previous. To the point that another neighbour rehomed their cat to avoid it more injuries. They have spoken to agressive cats owner who sayys cats will be cats. Currently my friends cat has returned after 3 days hiding with putrid wound has been treated by vet wound has been debrided and left open and cat on meds and has. Elizabethan collar. Cat is very distressed. Any suggestions for future.   So far I have suggested zyklene dap collar and diffuser and then keeping cat as indoor cat

Think I'd say the same and maybe the dap plug in near cats bed?

Could they set up a run outside, so the cat can have some freedom without having to encounter this other one?

It's a shame there isn't anyone to report this to, it's really not fair :-(

It's Feliway for cats. Yes, this is just one but many of reasons for why cats should not be allowed outside. I'd strongly suggest they blood test the poor cat to see if it has been infected with FIV as that is spread via deep bite wounds. :( I'd also second Nikita's suggestion of a safe run. We're not allowed to post links to our own websites here of course but if you want it sent privately, I have photos of my cat run (both from previous house and current one, done in two different ways as in the previous house we had patio doors, in this house the run is entered via a window) on one of my websites.

Is the offending cat neutered?    

If not, it may be about due and the owners might be persuaded to get the cat done?

I second the outside run though, it isn't just other cats that put yours at risk, no end of cats get hurt in traffic :(

It's possible to cat proof your garden without making a run have a look here

http://www.fabcats.org/owners/fencing/info.html

Thanks guys for your iideas will pass them on . Yes of course feliway for cats silly me ! They don't know if cat is neutered and apart from my tongue in cheek siggestion of catnapping to neuter if not its a shame that there are no laws covering cats !

there might not be a law regarding cats, but you could say i saw your cat attacking my cat and the vets bill will be sent to you ,  i know it sounds awful but evidence might go a long way to getting this stopped is it just other cats it is attacking, as i saw a lady the other day with horrific wounds on her face due to her neighbours cat attacking her she looked like she had been in a boxing ring.

Poor lady that's awful. I wonder how  that cat came to attack her like that.

she was tending her garden and it lept out the borders and attacked her this is not the first time this cat has attacked people either , was in the papers was horrible to see

Nasty !

How to cat proof a garden

And try Pet Remedy as a more natural alternative to Feliway, that stuff hits the back of my throat when we use it in the cattery and makes me cough.

Some cats are very aggressive I have had one of my elkhounds attacked by a cat, totally unprovoked she did not even look at it but it scared her ridged and turned her into a cat aggressive dog she seemed to have the idea that you got in first or you got hurt.

Thank you for your comments I shall pass them to my friend and hope she finds a solution

That wouldn't stick, judgedredd, cos cats aren't liable outside hence the way cats get freedom.
This happened to my cat a few weeks ago.  Him and the said cat are fighting for territory and my cat came home with an infected wound.  £70 vet bill later but it is swings and roundabouts.  A couple of months ago, that said cat got a bad scratch off mine in his eye which required treatment.  Me and the neighbour chat about them but mine has been an outside cat for 10 yrs so I won't keep him in and she doesn't believe in restricting cats so we are at a deadlock.  We split the time.  I let Axel out at night and she lets her cat out during the day.  Both cats are neutered boys.
Funny thing is, just this weekend, the 2 cats were sitting in the street together for ages.  Maybe a truce?