Yes a lot of collars will leave marks (rub) on the neck fur over time.
I found one type that doesn't leave marks, but it's made for dogs so I had to modify it (grind down part of the clasp) in order to make it breakaway.
I found one type that doesn't leave marks, but it's made for dogs so I had to modify it (grind down part of the clasp) in order to make it breakaway.