While religion is a routine obligation, superstition is the true faithful belief of Tom and many others. The various cures for warts that Tom and Huck discuss cannot be questioned, and there is always an explanation when they fail.
Dead cats are especially important to the boys, as they are very powerful and have many uses.
Although the trick Tom uses to find his marbles fails, he cannot believe that the superstition is false. Even though it takes three tries to find his lost marble a minute later, the fact that he found it is proof to him that the tricks of superstition work. Tom and Huck at first believe that the howling dog means they will die. When they see it howling at Muff Potter, they understand that he is in trouble, not them. Since they never doubt such things, they know nothing they can do will change his fate.