But if "эти кошки" is understood as a complete sentence, Landsend is correct and it does mean "These are cats." Эти is still an adjective-like pronoun as Olimo says, but now it is the predicate adjective following a linking verb.
With apologies to Crocodile Dundee: "You think those are cats? Those are not cats! These are cats!"
Note added 2 February 2017
I was a little confused when I wrote the above. "These are cats." is "Это кошки." I may have been confused by thinking about sentences such as "Те фигурки сабаки а эти кошки."
Thank you for this clarification. I jad the same question wondering why it could not be, "these are cats".
I found this helpful to get a sense of distinguishing between "this ----" and "this is a ----" for singular VS. plural and Fem. Vs Masc.
this cat. этот кошка. these cats. эти кошки. this is a cat. Это кошка. these are cats. это кошки.
this dog. эта собака. these dogs. эти собаки. this is a dog. это собака. these are dogs. это собаки.
Trusting google translate here!
I can hear 'эти кошке' and it's a bad pronounciation both by female and male voces. There is no vowel reduction in this case, it should be 'эти кошки'(female cats) or 'эти коты' (male cats)
ChrisRodrig1390 has already explained the difference very well. Look a couple of comments above.