Love the concept of this pet pen, but it just doesn't hold up. I bought the medium size for my little chihuahua / terrier mix (under 5 lbs) and definitely wouldn't have gone any smaller. It was great the first week or so, but once she figured out she was tall enough to reach the the top it didn't take her long to chew thru the fabric and escape. I think we got about 2.5 weeks use out of it. I would recommend investing in a traditional wire kennel for full time use. This might be good for a trip or to take when visiting friends or family, but wouldn't recommend it for full-time use.