Deerhounds - how we ‘Broach’ the subject

Here’s a fine little piece of art I can tell you little to nothing about. I don’t know the period from whence it came, if it’s gold and silver, nickel and more nickel or if it is a one off or mass produced object. What I can say is it measures no-more than two inches across and clearly depicts a deerhound in pursuit of the quarry. What can you tell us about this brooch?