Trying to work out whether a website is up-to-date is never easy (and can often be impossible). Your best way of checking is probably to simply pick up the phone and give them a call.
However, looking at those links I gave you the other day, the 7th Heaven (Newtonabbey) one seems to be up to date because their 'events' listings are current.
The Assisi link should also be up-to-date (for the same reason)
I can't see any date information on the Dogs Trust (Ballymena) website but, since its part of the UK-wide organisation's website, I'd expect the information to be current.
The Mid-Antrim site should also be up-to-date because clicking on the 'Contact' link shows that three cats have been added to the listings within the past 8 hours.
However, as I've said above, PHONING is almost certainly the best way to check the current situation with regard to animals waiting to be re-homed.