Trudy,

I operate a mirror of this newsgroup, and this subject is a source of frustration to many (thankfully not me). A good place to start will be some of the recent posts at
http://www.gardenbanter.co.uk/search...der=descending
There is also a cat FAQ at http://www.tmac.clara.co.uk/urgring/faqcats1.htm

On a similar note, THE most common search term on the GardenBanter website is for Coleus canina, a plant that is supposed to deter dogs & cats because of the smell.

The people at bionet.plants are however, less than impressed with it's qualities.
http://www.gardenbanter.co.uk/showth...8986#post78986

Good luck.