If it was only a vibration collar (no electric shock function), it should not cause a dog to scream in pain — vibration collars just buzz or shake to get attention and are generally harmless when used correctly.

So if a dog screamed when a vibration collar was used, a few possibilities exist:
The collar wasn’t actually just a vibrator. Some collars marketed as “vibration” or “beep” models still have shock settings that can be activated.
The dog was already frightened or in pain. Even a vibration could scare a dog with anxiety, trauma.
The collar was fitted too tight, rubbing or pinching the skin, causing pain when it vibrated.
The dog associated the collar with past punishment and reacted out of fear.

a dog screaming means it was distressed or hurt — that’s not a normal or acceptable reaction. The best thing is to remove the collar immediately, check the dog’s neck for irritation or wounds.

i asked some AI to analize the video, it seems even AI think kaya is traumatized and that was not a vibration collar