I borrowed my mentor/friend's whelping box for the first litter that I have had in 35 years. It is a home made wooden box approximately 16" high and 6' by 6' with 2 by 4 pig rails. It was perfect. My husband went to Lowe's and bought two sheets of showerboard and sealed the joint with air conditioning metal duct tape. We put the showerboard sheets on the floor and then put the box on top. The front of the box is hinged to make it easy for you and for the bitch to go in and out. We had decided that if we both had bitches due close that one would use that box and then the other would get the Whelp-n-grow because it is easy to clean and adjust for the needs of the litter.
I have a little heartbeats too and like the construction. I did find that puppies chewed the upright posts but they should be easy/inexpensive to have replaced when necessary.
I have the 4x4 with the 2 ft extension and found that a 2x2 rabbit pan with equine fresh worked well for a potty box for a litter of 5. For a bigger litter you might need two pans.
I had a couple of handles put on two sides and set it on a sheet of linoleum. With the handles to lift one end tnen the other I could tuck 4x4 fleece pads under the edges. I used a 4x4 pooch pad from revival under the fleece for additional absorption. The whole system worked well for me in the space I have for an occasional litter.
If you do litters more often you might find the Jonart to be worth the extra money but for me this worked.
