North Yorkshire Police are currently suing information following the incident in Newlow, Borrowbridge.
A police spokesman said: “It happened at 2:45pm on Thursday, February 13th, when a brown Lurcha dog attacked a Westy-type dog and was seriously injured.
“Unfortunately, the dog died after that.”
Anyone who witnessed the incident or has information can contact Colin Irvine at Colin.irvine@northyorkshire.police.uk or call North Yorkshire Police on 101, select option 2, and then Colin Irvine Please ask for.
Alternatively, you can contact Crimestoppers anonymously on 0800 555 111.
Please quote reference 12250027933 when providing information.