XS and Cat sizes are offered in the same width with the same available hardware options (while quantities last) however the Cat collar will feature a breakaway buckle that will pull apart under stress to ensure your cat can escape should their collar get caught on something.
A XS collar will not have a breakaway buckle and will remain clasped if walking your dog on leash.
We only ever recommend using breakaway collars for cats.
This is to ensure their safety.
Do not order a cat collar for your dog as the buckle will not remain clasped when on-leash.