Let’s break that down:
First few minutes:
The first few minutes of isolation are the most stressful for a dog, according to the researchers.
Dogs will howl, bark and whine constantly.
Up to 30 minutes:
Anxious dogs will continue pining after their owner for up to half an hour.
Extremely anxious dogs will urinate, defecate or vomit, and can even try to hurt themselves.
The next few hours of being left alone depend on the personality of your pup.
Dogs that are predisposed to being anxious can spend hours pacing up and down waiting for their owners to come back.
Typically they spend less than a minute resting before getting up and moving again, so their rest is very disturbed and the dogs can often be tired when the owner returns home and only settle down to sleep at that point.
With that said, if your dog gets hyped up when you get home, even when tired of barking and howling for you to comeback, he gets over it because he loves you more than anything
Take care of your puppy.