Is TS4 Cats & Dogs worth it?

Well, value is in the eye of the beholder. I'd say it's worth the 40 USD. Others would say it's good but worth a smaller amount.

If you can wait, you should wait for a discount in the coming weeks just to save up. I was excited so I preordered. :D

Since animals bring a whole new dimension to TS4, I'd say yes.

Yep. I cannot wait to become a vet.

I think it's worth it. Sure there are a few bugs and glitchy things but for the most part I am very satisfied and think it was worth the purchase price. I pre-ordered and paid €40. It was an early birthday gift to myself. My birthday isn't for another 10 days but I couldn't wait that long to play, ha.

Lots of lacking features, can not even Kitty train kittens

Yes - they did an amazing job on this pack. I really like it a lot.

I got Cats & Dogs cheaper using a voucher and I'm glad that I was able to do that. I think for the price there should have been a lot more content included.

There are only 2 bed types: small (round) and large (square). In previous versions there were mattress type beds, basket styles and outdoor kennels/houses.
Also, there are only 3 or 4 toys (2 balls and 2 squeakers). What happened to tug toys, teddies and novelty hot dogs? I do like the toy baskets but my dog hardly uses it!

I am looking forward to setting up a vet clinic and create-a-pet was much better than I had anticipated.

If you complain about needy pets, just press CTRL+SHIFT+C then type testingcheats true, then shift click on the mailbox, then click alter needs, then do fill needs world, then repeat, but instead say disable world need decay

Also I didn't pay for it so I don't care

Haven't bought it yet as am still researching. Am likewise finding throughout the forums an enormous number of complaints/bug reports, lists of things former pets versions had but this does not, and general not living up to expectations. Yes, a lot of folks are deliriously happy, much of which seems to come from the cuteness factor. Will admit to being attracted to the new town and a fair bit of the build/buy, but am not parting with $40 to get just that. If I get it, it will be on a deeply cut sale.