Tell me if this is right:
"Vi elsker katter"
= We love cats (in general). Example: a culture that puts cats in a place of honor, regardless of opinion on any specific cat and not with reference to any specific cat. Possibly this could be heard in a classroom discussion with students of Norwegian who are explaining to their peers which animals are popular in their home countries.
"Vi elsker kattene"
= We love THE cats (a specific group). Example: the cats someone owns. Sentence could be heard from someone sitting nearby discussing the cats with a guest, expressing fondness for these specific pets.
"Vi elsker disse kattene" [?]
= We love these (specific) cats. Similar to "Vi elsker kattene" but very specifically and unambiguously referring to a group of cats you are showing someone.