You mean that you for get how non-Indo-European, i.e. Turkic, Turkish is. Not only Latin (Romance) languages use the plural after numbers, so does all Germanic languages (I think). However, not all Indo-European languages do that, Welsh, for example, which belongs to the Celtic branch of the Indo-European language family, uses the singular after numbers. Also, Russian uses the genitive singular after numbers 2 and 3 and any number that end with those digits.
How would you want to "make it determinate"? As far as I know, Turkish doesn't have a direct equivalent to English (or generally European) indefinite and definite articles. If you're talking about the definite-accusative, that would require "kedi" / "cats" to be in accusative in the first place, which isn't the case here.