At about 4 months old, he may have started teething. From his behavior you describe it sounds like that might be it. if you can get a look (without him biting, don't if it's too risky — sometimes when they're being goofy and rolling on their back and stuff you can catch a glimpse, also when they're asleep and really out it's easier) see if he's teething. Just a quick peek under his upper or lower lip and it's pretty apparent, missing teeth or short teeth where adult teeth are growing in. He may have started teething. Also right around the time start to lose their baby teeth and their adult teeth come in, puppies are undergoing some hormonal changes, too. So they've got something incredibly uncomfortable and frustrating going on in their mouth which makes them a little cranky and changes in hormones on top of that, it's a rough time to be a puppy and a puppy parent.

Getting a few new toys that are for chewing would probably be helpful. New toys might interest him in them.I'd personally get something like rawhide chews/bones or bully sticks for just chewing on, a toy like a Kong where he'll have to chew and he'll stay busy trying to get the treat out and a bone made out of nylon or rubber like a Nylabone. Having a Kong around to fill up and give to your puppy when you're feeling stressed or worn down and need to breathe for a bit is really helpful.

Get rid of the cat food and find a dog food he likes. (Or am I misreading that and he is just eating cat food throughout the day? Either way, stop allowing it. Maybe by getting a few new toys to chew on, it'll distract him just long enough for you to get rid of it or put it out of reach and sight.) Keeping a leash, nothing fancy, just a simple leash, can help with behavior and training. Depending on the behavior, if he's not being destructive and he's not trying to signal that he needs to go out to go potty or that he needs more water, ignoring his behavior (whining, begging, etc.) and not looking at him or saying anything to him and just acting like he's not there instead of giving him any attention (even negative attention by and trying to get him to stop) will send a message pretty quickly that it's unacceptable. Obviously this isn't possible for a lot of situations where you do need to stop him from doing something, like if he's chewing something he shouldn't be, redirect him and give him something he should chew instead. Get some chewing deterrent spray, it should help a lot if there's places he's drawn to chewing.

Are the bouts of energy 'zoomies' (a FRAP or frenetic ... (more)