I used reptariums for many years- from the time they came onto the market until last year. Mostly I used 175 gallon size. Last year I had well over 100 in use.
I never had a problem with cats. One time a raccoon broke into a cage and ate all my dilepis babies, but that cage was aluminum screen. I knew it was a coon cause he left a poopie behind for me in the cage which I took down to the extension service for identification. But that was a very unique time- where I live now I've seen dogs, cats, coyotes, and even a bob cat stroll through the cages and none of these every even peered into a cage.
Some tips-
For branches, drill little holes in each end and zip tie from the hole around the frame to hold tight. Use wire cutters to snip the excess off the zip tie so it looks sweet.
For a better more sturdy reptarium- order 1" pvc corners online or from your local plumbing supply store and replace the frame with 1" pvc frame (or any larger size over 1"). It's actually better to start that way and then cover with a reptarium replacement cover. It's much cheaper too. I did my first 64 175 gallon reptariums like that and I also glued a bottom to the frame (the stuff used in bathroom walls). They were so sturdy they could hold 50lbs of sand in the bottom for desert lizards if I wanted and still have rocks, bricks, cinderblocks, driftwood, etc and be stacked 3 reptariums high. Even with all that weight I could climb on top of the frames.
The black frames that come with them now officially are terrible. The kits I ordered had frames that couldn't even be put together without cracking. They are the most shoddy cheap crap available. If that happens replace the cracked piece with appropriate internal diameter pvc- it's stronger and less brittle. It's also very cheap- I mean c'mon how cheap is the black stuff when a strong replacement piece of appropriate diameter and length works out to less than a buck retail?
Keeping desert lizards in reptariums is a terrible idea by the way- anything but chameleons will eventually dig through the cover, requiring replacement or patching.
Reptariums are difficult to keep clean also- they are fabric- hard to disinfect (think parasites more than germs).
Also- BE CAREFUL WITH YOUR LIGHTING- I don't use them now because last spring I had a terrible fire in my lizard building that started when a flourescent light ballast on a ceiling light malfunctioned, catching a bank of reptariums on fire that was a few inches below the light. The fire spread very very well from reptarium to reptarium and even burned the frames (and pvc frames). They burned very very hot- reptariums across the room melted. It was a horrible horrible experience where I lost over a decade of work and many many precious lizards some of whom came down from many generations in my care and some unique in all the world genetics in a few and I lost lots and lots of money- I will NEVER buy another reptarium or recommend them again.
Lastly- you can keep the zipper running smooth by spreading a little vasoline along it a couple times a year.
