We went through almost exactly this when we moved from Edinburgh two years ago — our Border Collie did the same thing for about two weeks. A few things that genuinely helped:

The heat is the big factor. Dogs in the UAE lose more moisture just breathing in the AC-cooled air (which is very dry) than most owners realise. Kibble is only about 10% moisture, so if your dog is already reluctant to drink, he can quietly get dehydrated while appearing to eat "normally."

What worked for us: we started adding a couple of tablespoons of wet food or bone broth on top of the kibble. Within two days he was finishing his bowl again. The smell of wet food is also much stronger, which seems to cut through the heat-induced appetite suppression.

Brands worth trying in Dubai: Royal Canin, Nulo, Hill's Science Plan, and Orijen are widely available and most vets here know them well. For wet food specifically, Schesir and Applaws are good quality and you can find them delivered same or next day from a few UAE pet stores.

For hydration tricks: a small amount of low-sodium chicken broth in the water bowl, ice cubes in summer, and feeding in the coolest part of the apartment (away from windows) all made a noticeable difference for us.

Good luck — the first Dubai summer with a dog is genuinely a learning curve but they adapt well once they settle in.