Before we start, it's important to note that Chihuahuas can develop food allergies at any stage in their life. Even if they've eaten the same type of name brand dog food for years, their body chemistry could change all of a sudden, causing them to experience an allergic reaction from it.
The crew also filmed many scenes in the north of Vietnam, as well as Oahu, Hawaii. No doubt the shots of Vietnam's tangled jungles helped to establish Skull Island's authentic 1970s feel. Check out the island for yourself in the trailer for Kong: Skull Island:
None of this has any direct relation to the last major Kong movie, the majestic (if overlong) Peter Jackson epic of a dozen years ago. Instead, Skull Island belongs to the same cinematic universe as the recent Godzilla reboot, allowing for a future war of the brand-name Gargantuas.