Not in OED
Posted by R. Berg on May 14, 2002
In Reply to: Spagged by a cat posted by Chris W on May 14, 2002
: Has anyone come across this phrase - may be derived from Welsh/Gaelic. My recolection was it meant to be scrammed or scratched by a cat. Spag/Spagged
The Oxford English Dictionary (1st ed.) has no "spag."