Bit worried about pup- could use some advice please

[couch25cakes]

I'm a bit concerned about our almost four month old puppy; he seems to have lost some of his sparkle. He's only been out for walks since last week and he had a slightly too long walk yesterday as my mum didn't realise he shouldn't be on long walks. Also, after two weeks of routine where on work days he's been crated for a couple of hours morning and afternoon with a walk and play at lunchtime, since Monday night he's had my mum here so hasn't been crated other than at night. Last night he took himself off to his crate at 10pm (first time he's done this, normally we put him in at about 11, he goes down happily). Today he woke as normal and was full of beans, mum said he played in the morning then went and sat in his crate for an hour (he's never done this before). At lunch time he seemed quiet, wasn't into his toys or treats, filled kong etc. I put him in crate for an hour while I went out, and when I got home he was a little better. He seemed back to his naughty self later on tonight, but has been sitting and snoozing in his crate for a lot of the evening, where he would normally be trying to eat everything and snoozing with us on the sofa.

I'm not sure if I should be concerned. His toileting has been normal, but he's picking at his food and not eating it when it's put out but picking at it later, eventually finishing maybe 2/3 of it. He also has been mad about chewing since we got him last month and has been trying to gnaw everything he can, especially cardboard, so I'm wondering if that's causingn a problem. But just as I'm gettig ready to call the vet he perks up and bounds around the place trying to eat dd's shoes and trying to get good from our plates. And then just as quick he's disinterested in food, play etc. also, we bought his brand of food at the weekend but I think we got a different flavour by mistake, if that's relevant.

Could he just be tired and out of routine or overstimulated? Do puppies have 'flat' days? Is he just growing keen on his crate? Or is he ill? Should I take him to the vet? I'm happy to but reluctant to fork out £70 for an exam if he'll just tell me that puppies have days like this. I'm new to this puppy lark and don't know at what point to me the decision to head to the vet?

What do you think?

Teething?
He could just have got more tired on the days with your mum, puppies need downtime to sleep while they're growing. He obviously regards his crate as a safe nest where he can go & rest.
As to going off his food, it could be the change of flavour. But how often are you feeding him? Puppies gradually cut down as they grow on the number of meals, from four times a day when you wean them, then down to three & later to two.
It sounds like he's still full of energy most of the time. If he's not vomiting, his poops are normal, he's eating & no raised temperature I wouldn't worry too much. Just keep an a eye on him.
And give him something to chew on if his second teeth are coming in.

Thanks, he seems full of beans this morning and has eaten well. I'll keep an eye and try to implement a more regular routine for when mums here and for the next few weeks which allows some crate time each day so he doesn't get overwhelmed.

He went to town on a stray plastic milk bottle this morning so I think his teeth may be an issue, he has loads of chew toys but it seems to be cardboard he loved the best

Many thanks again

Raw carrots are good for teething, give a whole one not chopped up. If his mouth is sore it helps to pop a carrot in the freezer & give him that. They usually like the sweetness & the cold is soothing.
As you cut his number of meals you'll need to make each one a bit bigger do he isn't getting less food.

Meant to ask, what breed is he?

He's a bichon x mini schnauzer.

Thanks, might try frozen carrot :)

Cute

At 3 months they start losing their baby teeth - so he is teething and will continue until 6 months old when he should have all his adult teeth. he is still a baby and needs lots of sleep
So long as he is gaining weight and not losing it he will be fine.