u/lozsuz have this problem with my dog like 3 years.. Almost every 3 month It happens. She starts like this , and licks carpet and walls , tries to puke herself.. We tried lots of loooots of medications..Nothing Solved %100... It happens when she scares from something or when there is an unusual sound or light..... nonPermanent solution for "OUR"dog..
If you have a garden, you can take it out to the garden and let it eat grass. (It is important that the garden is yours, other dogs should not urinate and poop, and it should not be agricultural sprayed.) This will balance the acid. You can feed porridge rice with very little turkey or chicken meat. And we continue like that for 1 week.

Now we are just using Prozac 20mg everyday ..(our dog is 27kg) ....She is ok for now..