I have heard arguments recently about higher education in the US being a bubble. But what about Pets? Animal based bubbles have a long and fun history. For example Alpaca's and Ostriches twice have been bubble commodities.
There is a really interesting article on how spending has changed during the recession here. It presents this table

From these figures could pets also be a bubble? The cat has hardly changed in thousands of years. Certainly not enough of a recent efficiency increase to make it worth a 14.4% growth in costs. So keep an eye on the costs of pet ownership especially of the fancier breeds to see if bubble thinking comes along.