I've been wondering this for a bit now but is there a true cap to how many items a pet can have in their treasure chest? I know we can keep expanding it but I'm more curious as to if there is a maximum of how many time you can expand the treasure chest of your pet?

my pet Gnats is at 587 items. I plan to stop at 600, if that helps any?

There is an achievement for 1000 items in a pet's treasure - prize . I don't think there is any kind of cap, but

My biggest treasure chest has 2533 items / 2545 slots >D So if a cap exists it's very high

Wow! And I thought I had too many at ~1400. That pet profile would always crash when looking on mobile so I decided to cut back on it just the other day... Removed around 350 items but I can't justify removing more...

Wow! And I thought I had too many at ~1400. That pet profile would always crash when looking on mobile so I decided to cut back on it just the other day... Removed around 350 items but I can't justify removing more...

Interesting, so it seems it's less a worry about the cap and more a worry about the loading it takes when the number get's high.

My Halloween pet has 3,250 treasure chest spots, all filled. If there's a cap you're not at it yet.