PetMD recommends getting a dog checked by a vet immediately if it starts drooling excessively for more than a few minutes or the drooling reoccurs regularly. This is especially true if it is accompanied with changes in behavior, such as loss of appetite, irritability, aggressiveness, vomiting or excessive pawing of the snout. read more
I am concerned that the dog has had excessive drooling for such an extended period of time. If something is caught in the dog's teeth, the problem should have resolved itself within several hours. There are many reasons why a dog starts excessively drooling. The most common reasons are due to dental issues. read more
Open-mouth panting and breathing, which are signs of anxiety, can cause your dog to drool. To make him more comfortable, try putting him in a pet harness or canine seat belt in the back seat without driving anywhere. read more