She seems to hate these intruders. Normally a peaceful and amicable kind of creature, she is transformed into a barking, lunging, frenzied maniac when she sees them outside her house. Both cats appear to understand just which parts of the garden Penny can't reach. That's where they sun themselves or stroll around in a leisurely fashion.
I've tried desensitising Penny by standing in full view of her, holding and stroking the felines, but I don't think it's doing any good. Or, if it is, it's going to be a long process.
In view of all this, I was interested to get an email today from Dr Jon, from PetPlace.com, about the difference in cat-tolerance between different breeds of dogs. Their guest columnist, The Irreverent Vet, has contributed an article that says, in part:
The dogs that are best around cats are dogs that are not predatory and were raised around cats. Especially, dogs raised and socialized around lots of different cats, including your cats.Dog Owners Guide at canismajor.com has an article called "Making peace between dogs and cats; is co-existence possible?" in which they say that the level of prey drive in the breed or individual dog can give an indication of how hard it will be to teach the dog to live with a cat. Having watched Penny leap on her soft toys and shake them to "kill" them, I'm pretty sure her prey drive is high. She is, after all, some kind of terrier, even if we're not sure what kind.
I'm not fond of the method that was suggested to acclimatise a dog to a new cat, as it involves 'correcting' the dog by having her on lead and jerking the lead if she moves to investigate a cat being held by an assistant. However, it does mention the alternative, having the dog on lead and rewarding for quiet behaviour around the cat, thus associating cats with pleasant experiences. This seems to me a more long-lasting method of changing behaviour. The idea is that the helper will bringthe cat closer each time, with the whole process taking as long as necessary. It may take weeks or more.
There was a further link on this page to "Fighting furry furies? Dogs and cats don't always have to fight like cats and dogs". It doesn't go along with the idea that cats and dogs are natural "enemies", but points out that they are both predatory species. There are a number of ideas about how to teach dogs to accept cats.
After thinking about all this, I reckon I'll continue with my method of holding the cats where Penny can see them, but I think I'll get a helper to feed her treats whenever she is quiet and calm. The problem is, of course, that I'm never going to put it to the ultimate test, because I wouldn't want to bring someone else's pet near enough to be frightened by Penny. So, I guess unless we decide to have a cat ourselves it'll never be resolved.