Hi XXXXX,
What is making him so nervous?
What breed of dog is it?
Is the dog on any medication or have any ailments?
Thank you for that information. Benadryl is often given as it makes them drowsy or over the counter melatonin or you can call your vet and ask that they give a couple of tranquilizers. You also want to be careful how you treat him when he is in this state as if you coddle him he will think this is the way you want him to act, so petting and sweet talking should not be done unless he is calm.
It is human nature to coddle, but not dog nature and you'll be feeding into it.
Benadryl and dosing http://www.petplace.com/drug-library/diphenhydramine-benadryl/page1.aspx
Melatonin http://www.petplace.com/drug-library/melatonin-melatonex/page1.aspx
dog training consultant
24 years training & behavior,pet first aide, Therapy dog eval., PA Animal Response Team