You definitely don't have to spend excessive amounts of money on a good vacuum cleaner if it's simply for pet hair. Firstly, it's always good to buy quality, not because you need it for the animal hair, but simply because its logical. Secondly, anything with a good suction power will do the job. Good filtration & good suction. Those are the two rules. Lastly, for pet hair, all you really need is a good brush head to get rid of unwanted hairballs and what-not. A revolving brush head at the end of your vac, combined with good suction, will be more than sufficient to keep your house from becoming a holiday-inn for furballs.

What a Pet Vacuum has to have –

Suction and Power.  Most vacuum cleaners that are made and sold at the department stores are not vacuums at all but should actually be called sweepers instead of vacuums.  The concept that they run on is a AGRRESIVE brushroll that sweeps your carpet and then augers the debris to a suction tube on one side.  The problem with a suction tube on one side of the vacuum head is what happens to the dirt and pet hair on the other side of the head where there is no suction?  The dirt is ground down deep in the carpet and the pet hair WRAPS AROUND THE BRUSHROLL.  If you are a pet owner you will know how frustrating it is to constantly be cutting out the hair out of the brushroll.  You are doing all the work instead of your vacuum.  So what you need is a Vacuum with lots of power and the suction power cleans your carpet over the brushroll.  That way instead of the pet hair wrapping around the brushroll it is sucked into the vacuum and into the bag chamber.  How is this done?  Your vacuum needs lots of power AND it needs to have the suction tubing IN THE MIDDLE OF THE HEAD.  That way you have suction power all the way across the head so the pet hair is sucked up vs. wrapping around the brushroll.

Large vacuum tubing.  You need to have large vacuum tubing so there is plenty of power and the pet hair does not clog in your vacuum tubing but make it to your bag. 

Stiff bristled Brushroll.  The brushroll bristles should be fairly stiff so that it “combs” your carpet of pet hair.

What a Pet Vacuum should NOT have –

1.    Suction tube on one side of the head (it should be in the middle of the head)
2.    Small vacuum tubing
3.    Vacuum Tubing that has lots of bends or turns in it.  It is right there that it will clog.
4.    Soft bristle brushroll