So, I am attempting to order Chloe a Baskerville Ultra muzzle...however, I am so not sure what size I need since two different sources are telling me two different things. I measured her snout length and her muzzle circumference with a piece of string, then laid that out next to a measuring tape. I measured her snout length as 3.5" and her muzzle circumference as 9.25". (She's a 45 pound Collie/Aussie mix.) I was looking around at a few different sites for sizing information...Leerburg says for her measurements, I need a size 4 muzzle (Size 4: 3.25", 12.25"), but another site (some online pet retail store) says a size 2 muzzle would fit her (Size 2: 4", 11.8"). So now I am royally confused. I know quite a few members on here have one of these muzzles so...which size should I go with?