Yes, the Stealth is the best choice for replacement and for cleaning up after the dogs. There is a huge difference in quality from the Butler, you'll be surprised. Also, use the TornadoPower cloths. Run them, several of them, through the hose, duct work, and leave them in the Beam. They clean internally and smell great. Yes, you should get a new filter. Please measure the diameter of the inside of the can where it is seated http://builtinvacuum.com/retail/shopretail.php?part_no=710B,711B
. When you need to remove the filter pull in from the edge, it flexes and falls out. If you have any other questions please let us know.