Been having a huge falling out with a lady here who counts herself an authority on dog care on Tamborine Mountain, Queensland. I had never heard the spelling "spay"- only ever knew it as "spey". I said to my mind, "Spey" must have been the original spelling. She went butcher's hooks and claimed "spay" was the only correct spelling and always had been. Over the years heard people using all sorts of derivative terms for "spey" like spading and spaded, which I knew to be incorrect. Spey, speyed, speying, is correct.  Thank you to those on here who brought this topic up. It is still current in 2022. Could "spay" be the Americanization of the spelling?  Anyone know?