I am looking for UK based stories ideally within the last 5 years, of
pets behaving badly. IE Pets costing their owner thousands of pounds
due to damage they cause, or breaking up a relationship etc. Any
stories of pets repeatedly acting badly really.

There was a series recently on Channel 4 called 'It's Me Or My Dog'
which would be great with Victoria Stilwell who is a dog behavourist.

I think the progs are now being re-run.

Here you go:

http://www.victoriastilwell.com/

She's also written a book.

My cat, Albert, has driven me MAD many times ;)

Steph53