i had one did the same thing no slobber but he ate right through a (strong built steel kennel)an tore the door off . i built a outside heavy gauage cattle pannel kennel an he did the same thing to it. You got to get this under control or he may do it outside to i had to learn the hard way

start off by kenneling him while you are at home on an off so he will get use to it. as EODLT said give him some toys some of the other guys will have some good tips to good luck !