Young dogs begin to explore their surroundings as soon as their eyes open. Mouthing, chewing and biting objects is a part of this exploration; however, if left unattended your puppy can get injured and can damage valuable household items.
To be effective, a correction must be timed correctly and must be appropriate. There is no sense in correcting a puppy hours or days after it has chewed a valuable item. Unless your puppy is caught “in the act” or only mere seconds after it chewed an inappropriate item, a correction will accomplish nothing. Your puppy cannot make a logical connection between your reprimand and its chewing behavior unless a correction is given during or immediately after chewing.
If you return home to find that your pet has damaged something, yelling and hitting the pup is ineffective and will only teach your pup to be scared of you when you come home.
Punishment should serve to startle your pet, distracting it from its current objectionable pursuit long enough for it to detect your displeasure. Substitute the objectionable activity (chewing) immediately with an alternative and acceptable activity. If your puppy is chewing on your slippers, for example, say “no” in a firm tone and gently remove the slipper (without playing tug of war). Follow this immediately with an acceptable toy or rawhide bone and immediate praise (“good dog”).