Thats is a symptom that the dog might have rabies see if he is actin a lil crazy. I think he either has rabies or he jus ate a bar of soap lol.

This is really not normal and the dog should be taken to the vet. ASAP!!!

If a dog runs around enough he/she may get foamy drool from panting as well.

Dogs with rabies don't foam at the mouth. the jaws may lock open making the dog drool but they don't foam.

dogs can also get foaming mouth if they go into Anaphylactic shock, which can happen from a bee stick, wasp sting, severe allergy. usually its not a good sign!
Sometimes it is just foamy from playing and drinking alot. and foaming, dripping from mouth.

You need to stay away from dog and call ANIMAL CONTROL immediately,so they can restrain the dog and take it for diagnosis,before it bites someone.

After playing, my dog's mouth gets foamy from drool when she's panting. I doubt it has rabies, but if you're worried about it, talk to the neighbors to see if the dog's been acting strange, and if it's up to date on it's shots.

Once a dog is infected, the virus may go undetected for several days or several months. it usually takes from 12-180 days for the virus to spread to the central nervous system. during this time is when the classic signs will be visible.

The first sign is a change in behavior (this can also be caused sue to other problems). the dog may not want to eat or drink and wants to be left alone. the dog may show signs of aggression or just be very lethargic. They may also show signs of paralysis.

If you are thinking there is a serious chance the dog may be infected then alert your neighbor of the situation. They should take it to the vet to be quarantined and watched for a week or so. this way they can see if the dog shows signs of rabies. the only way to test for rabies is to test the euthanized animal.

Edit- please don't assume the neighbors dog has rabies just from seeing the dog foaming at the mouth. many things cause dogs to do that.

Depends.

If its a puppy its more likely slobber, same with an adult. Find out if the dog has bin bitten by any other dogs lately? You should probably recommend taking the dog in for a check up and get them to ask the vet about symptoms.

There's not much you an do about someone else's dog, just steer clear!

— a lot of people mistake slobber for rabies.

Hope it was a help, Heather.

Foaming out the mouth is not really normal. Tell your neighbor to take him to the vet. better to be safe then sorry!