I use a Vari-Kenel, 23”Lx19”Hx19”W. New about $50.00. Perfect size for a 25-30 lb. beagle. Light with a center handle for carrying (even with the dog in it), easy to open and close and just hose out to clean. The beagle loves it.

"When the going gets weird, the weird turn pro."
Hunter S. Thompson