And plenty of other animals have been 'befriended'. There are 140 million ornamental fish in the UK - the market is worth £300 million a year. Then there are your cockatiels, cockroaches, iguanas, tarantualas and terrapins.
Anything can be a pet today.
Mintel puts the value of the UK pet industry at around £4 billion. Disposable income is increasing, and owners are happy to spend big. Even so, it's still hard to believe Selfridges' pet boutique can flog a Chesterfield doggie sofa for £495. Vets are getting in on the act, too - their bills can be astronomical.
But if you think your pet is making a pauper of you, spare a thought for Bumper, a Collie in Aberfan, South Wales. When her broken leg went gangrenous, her owner saved himself the cash and sawed off the limb himself.
Bumper survived, but her ordeal is further proof that it's not just the dogs who are barking.