As the narrator and new tenant at Wuthering Heights, Mr. Lockwood, sits at the end of the hearthstone, a "canine mother" sneaks around the back of Lockwood's legs, sniffing. When he pets her, she utters a "long, guttural gnarl." So, Mr. Heathcliff warns Lockwood to leave the dog alone, as he kicks her when she continues snarling.
She's not accustomed to be spoiled--not kept for a pet.
When Lockwood, believing that the dog would not understand facial expressions, makes "faces at the trio," the mother dog furiously leaps onto his knees. Knocking her back, Lockwood is forced to call to Mr. Heathcliff, who asks, "What the devil is the matter?"
Mr. Lockwood complains that the dogs have the worst spirits: "You might as well leave a stranger with a brood of tigers!" Heathcliff's reply is that
They won't meddle with persons who touch nothing....The dogs do right tobe vigilant. Take a glass of wine?
This introduction of Heathcliff in sympathy with the behavior of his canine's gives the reader an insight into his brutal character that is amused at Lockwood's discomfiture.