Cat Door Latch
This is a simple way to have a latch for the door that will allow cats in and will keep dogs out (to prevent them from getting to the litter, for example). Chain prevents door from closing all the way, and at least my 6mo old kitten (?) can paw it open if it's sort of closed. Super easy to unclip and reclip.
There are a bunch of alternative options here, like rope instead of chain, single clips, etc. We only use this when we need it, like when guests visit etc. The eye screw is unobtrusive and can be painted to blend better. The chain can be unclipped and put away during times of unuse.
The only real work here is screwing in the eye screw and cutting the chain. This chain is heavy wire, basically, so snips or a wire cutter works.
...something like this may work better to use if you have a bigger/stronger dog than the plastic ones online, as I've seen that's the main complaint. This chain has a load limit of 90lbs.
Supplies
Purchased at local tool supply (Home Depot, for example):
- 1 foot chain ($0.70/ft in store) - Everbilt #3 x 200 ft. Zinc Plated Steel Double Loop Chain, White 806540 - The Home Depot
- 2 small dual carabiner clips ($4.50) - Amazon.com: Nite Ize S-Biner Dual Carabiner Stainless Steel, Size 1, Black, 2 count (Pack of 1) : Sports & Outdoors
- Screw eye ($1.50) - Everbilt 3/16 in. x 2 in. Zinc Screw Eye (3-Piece) 824271 - The Home Depot
Total cost ~ $7 (...though I had some of this laying around, so it cost me $5)
Configure the Chain
Wrap the chain round the handle, and clip it with one of the carabiner clips, so it is tight. (NOTE: you could wrap a rag around the handle first, if you're afraid of scratches)
Add Eye Screw
Screw in the eye screw (may need to drill a small pilot hole)
Cut Chain, Add Clip
Pull chain around to where the eye hook will go and add second carabiner clip to the proper length, which allows your cat, but not a dog/child/etc.
Cut excess chain with snips or wire cutter.