I don't have any experience with this, my guys will drool a little if they are waiting for a treat, and my Dozer tends to drool a little more than Blossom sometimes because of his genetic defect in his jaw, he can't close his mouth so he drools. If this is new or not the norm for Radar and it continues, I would take him to the vet and have him checked out.

It is true that all dogs drool - especially when there is yummy food in front of them. Some breeds that have heavy lips such as bloodhounds and St. Bernards drool quite a lot because the loose skin around their mouths acts like a receptacle that traps saliva until it overflows.
If your dog drools and slobbers, there is nothing you can do except put some wiping towels at convenient locations through the house.
However, if there is a change in the "drooling pattern" of your dog (e.g. a normally "dry" dog suddenly starts drooling excessively), then you have to pay attention. Sudden excessive drooling usually means that the dog is not feeling too well. In extreme cases, excessive drooling can also lead to dehydration. Dogs with abnormal drooling may also show signs such as hard and listless breathing, head shaking, and scratching and pawing at the mouth.
Causes of Excessive Dog Drooling - In the Mouth

The cause of excessive drooling may be easy to identify if it is coming from inside the dog's mouth. If your dog is drooling abnormally, therefore, the first thing to do is to use a flashlight to examine his mouth. You may discover that the drooling is caused by any of the following:
Foreign Objects

Perhaps the most common cause of drooling in dogs is that something is stuck in the dog's gums, embedded in his tongue, or caught between his teeth. It may be a piece of string, a bit of bone fragment, a fish hook, etc. If you find a foreign object in your dog's mouth but are unable to remove it, seek veterinary help immediately.
Gum or Dental Disease

Dogs with gum disease such as tartar and gingivitis, as well as dogs with dental problems such as a bad or fractured tooth will also drool excessively.
One way to check if your dog has gum or dental disease is to smell his breath. Usually dogs with gum disease or a bacterial infection in the mouth will have really bad breath!

Injuries inside the mouth can also cause excessive dog drooling. Check for blood in the mouth and gums. Bleeding gums usually are bright red or even purple.

Tumors that occur in a dog's mouth (e.g. melanoma) can cause a dog to drool excessively. There are of course other signs that indicate the dog may have a tumor in his mouth, such as bad breath, bleeding from the mouth, and difficulty eating.
Other Causes

If you cannot find anything unusual in your dog's mouth, consider the following possible causes of drooling:

Many dogs will drool more than usual when they are traveling by car, because they suffer from motion sickness. The motion upsets their stomachs, causing them nausea which in turn causes them to drool excessively.

Dogs drool when they have pain. There are many reasons why a dog is in pain; for example, bloating, poisoning, infections such as ear infections or urinary tract infections, just to name a few. If you suspect that your dog is drooling because of pain, check for other telltale signs that may confirm your dog is in fact in pain.
Liver disease

Dogs suffering from liver disease may also drool excessively. Liver disease is a serious health condition and should be treated by a veterinarian without delay.

Perhaps the most serious and scariest cause of sudden excessive drooling is rabies. Luckily, this is very rare.
When to See a Vet Immediately

You should get immediate veterinary assistance when:

  • you cannot remove a foreign object from the dog's mouth;
  • you have reason to believe that your dog is drooling because of pain or poisoning;
  • your dog has a broken or fractured tooth;
  • you can see pus in the dog's mouth;
  • your dog's mouth is bleeding which cannot be stopped;
  • your dog's breath smells really awful.