[Ditter]

A loud long pant? What is that? By its very nature panting is the breath going in and out quickly, I don't think I have ever heard a dog pant loud and long. My dogs are deliriously happy but they don't make a sound like that.

[HairOfTheDog]

I'm not sure what noise they are describing either...

~shrugs~

[Rudder]

It's when the dog pants and vocalizes simultaneously. The vocalization is higher-pitched than a bark, less harsh and much softer than a bark and the dog actually draws the corners of the mouth back, almost like a smile.