Any chance of relocating the box? Unused bathtub or shower? Home Depot, etc. have a variety of low fencing. You’d just have to figure a way to make it stand up.

Edited to add, if you go to Amazon and search “indoor fences” there are some options. People use them to control animals in the house, fence off the Christmas tree. If kitty cannot jump it you’ll have to leave a little crack for her to go through. If she’s overweight she may not want to jump and use other places in the house.

That’s a clever idea.

There are pet gates that have a very small door in them. The cat may fit through, but not the dog.

They are essentially the same size, or the cat is bigger.😐

I use the Door Buddy. It's a strap that allows the door to open only wide enough for a cat, but not for a dog. It assumes that the cat can get through a smaller space than a dog, but in your case I don't know. Your dog is pretty small, but cats are generally more squishy. Good luck!

Thank you, my general experience has been that they can both fit through the same spaces. If the cat wasn’t fat your idea would work better!

Can you elevate the box on something the cat can jump on but not the dog?

Our dog was bigger but I put the gate on 2 paint cans (it was in the basement) and the cats would squeeze under it and the dog couldn't. It would depend if it works for you on how desperate your dog is to get to goodies.

I went with the curtain rod idea and it is working well so far! I have another area that’s more complicated and still working on that one for the best solution.

simple yet effective! i've used this method if i needed to separate a new great dane from the rest of the pack for a couple of days. :)

Any suggestions for heavy items that would hold this board in place and look better than two cat litter containers? (The 3rd has dog food stored in it). I like being able to remove the board easily when it is not needed and that it is more sturdy. This is to prevent her from coming right up to the door when I enter and turn off the alarm system and also to prevent her from getting into the cats food when I feed them.

what about something like this? you could use 2 or 3 of them.

https://www.wayfair.com/home-improvement/pdp/zingz-thingz-cat-cast-iron-wedge-floor-stop-zngz3453.html

if you do a google image search of "heavy duty door stopper", there are tons of ideas, lots of them you could make yourself. :)