Quite easy to make your own mate. Get some small brass plates, polish the gubbins out of them, incorporate them into your dog's collar, job done ?.
Oh yeah, before I forget, dog's got to be brindle, and fairly tall to tall, well, say not below about 25"ish. Job's always a tad harder with a smaller type. But can still be achieved, with diligence. Hope you have success mate ??