Our Pooch Potty boxes are not available in custom sizes due to our
own manufacturing process (they are manufactered out of thick durable
plastic). To make a new mold for a custom sized box would just be too
cost prohibitive for our customers.
However, I just discovered a company up in Portland that is custom making potty boxes called Doggy Duty boxes. When I inquired about the type of wooden material used to make these boxes, owners Amanda Shallcross & Noel Thomas wrote me back with the following:
To answer your question about our boxes - we do custom sizing and can ship them as well. Since our boxes are made of a very dense wood Ipae , they are quite heavy-so are not cheap to send. With the use of this wood, we haven't noticed any odor to the boxes. Because of the never-ending rain here in Portland, we had to use a box that was moisture/rot resistant. Ipae, the material we use, is what Ocean Piers are made of that sit in water year round--thus, it really absorbs no water and subsequently no urine. In addition, the boxes are cleaned weekly, so there isn't much opportunity for the box to become unhygienic.
I was very impressed that someone came up with the idea to use this specific type of wood. I have seen other competitors selling wooden potty boxes, however most of those companies are selling a version of a Planter Box . Unfortunately, planter boxes - although very attractive when you first set them up, in the end turn out to not be very functional. (see my blog that explains more about this)
Happy Pooch searching to you all! Every good dog deserves his own place to go potty!