My puppy is acting weird....

Hi

I have a Cavalier King Charles who turned 6 months old today but is acting weird.

Like earlier today we where playing fetch and after 10 mins she just turned away and went to her bed and no matter how many times i called her she wouldn't listen.

She has done this 3-4 times now (all recently) and she has been ultra sensitive, i caught her chewing on the table leg and i said Lilo no in a stern voice (was not yelling) and she turned away and went home.

Whats going on??? Is she going through doggy puberty???

She is still very playful and her tail is always waggling but why is she having these mood swings???

I rubbed her body, her joints and got her to run, she has no lumps or bumps and runs very well (even faster than me)

Adding that pic didn't work

10 minutes is actually along time to play fetch..my old boss said keep it short and leave them wanting more..a dog will get hot, then bored with the same thing over and over....try 3 retreives at a time..vary them..try one one way and one down another..making sure you are in the direct path so you can stop the dog on the way before they dodge around you to get the second. That is called a double. You can teach them to count this way..working up to a triple. they idea is to keep it fun..not work..old boss second rule for training a dog..make sure they are having 50 percent of the fun or they quit you cold. His last and i think most important rule.never give a command you don't enforce. If you say it, mean it. I think your dog just got hot...that is usally the reason they stop. EVen when two dogs are romping together, they usually do it in short bursts with lots of lay around an chew on each other time. The teething on the wood is pretty normal..if you don't want your woodwork damaged..gets some bitter apple spray.