Cheat viewers were left aghast on Thursday night after watching the series finale.
In the final instalment of the four-part series, Adam’s true killer was revealed after a number of shocking plot twists came to light.
Rose and Ben conspired to frame Leah for Adam’s murder, sending her to jail.
However, when their father arranged to meet up with Rose to talk, he convinced her to admit to the crime.
Once she had made the confession, he revealed that he had been wearing a wire the entire time, leading to her arrest.
In the closing scene, their father could be seen walking his dog, Hunter, in the woods.
The camera panned out to show Ben hiding behind a tree with a knife, plotting to murder Rose and Leah’s father.
What happened next left viewers seething — Ben lured the dog over, and appeared to attack the animal with his knife off-camera.
Shockingly, the labrador’s whimper could be heard in the shot.
ITV viewers were chomping at the bit over the violence shown towards the animal.
Many made the point that a cat had already been brutally killed in the opener of the four part series.
Taking to Twitter, people expressed their outrage in a flurry of fuming tweets.
One user said: “Was anyone else more concerned for the dog then her dad?”
While another remarked: “Well they sure hated pets in Cheat.”
And a third chipped in: “Why would you do that to the dog? F***ing monster.”