This post is courtesy of a friend and client who requested the topic and I intend on expanding on the topic at some point in the future.
Whining in dogs is one of those topics where you will see impassioned opinions of all sorts from dog trainers. One of my mentors who was also a coworker and friend insisted that whining was something dogs were unaware of and thus you couldn't control. This was one of the few areas that we agreed to disagree though I do agree that often dogs are unaware that they are whining, I also believe they can be taught to be aware of themselves whining. One day, I was working a two year old German Shepherd. He was a big boy and a complete and total cry baby. He'd whine to get to the toy box. He'd whine to go for a walk. Or to come in from the bad weather. Or because he was excited. Or just in general for no discernable reason at all. German Shepherds are notorious for whining, but this boy was particularly bad.
As I worked the dog and my mentor walked by, she noted: "Oh, hey, he's not whining. You must have worked him hard." (When he was physically tired he tended to whine less). I shrugged and said, "Yes, but also I'm trying to train him not to whine and it's working."
In my experience, dogs will typically whine for one of two reasons: 1) they need or want something and 2) they are self-soothing. Both can be beneficial for the dog's mental state in small doses. A dog whines at the door because they need to go to the bathroom, you go to let them out. The dog's physical need is fulfilled and the whining stops. Or, a dog is told off by another dog, to both placate the other dog and soothe themselves, they start whining to themselves. This provides a release to the stress they're feeling.
As I write this, the Ridgeback I'm boarding is whining at me because she would like her dinner. At her house, she is fed a few hours earlier than I feed my dogs and the adjustment is hard for her. I know what she wants, but the whining is not going to elicit the response she wants (I try to feed both my dogs and boarding dogs at the same time to limit the potential for the lone dog being fed feeling they need to guard their food).
Typically, when a behavior does not elicit a dog's desired effect their response will be to double down. That means, in this case, the whining will increase. Often, at that point, their owner will go "Okay, okay, I'll feed you." And now, the dog has learned not only do they whine to get what they want but they need to whine loudly and persistently.
There are some ways to break this cycle. With the Ridgeback, I can put her in her crate and she'll settle nicely. This would be a way of managing the behavior. I can call her over to me or I can ask her to go to her place and lie down and then praising her when she does. This would be a way of redirecting the behavior and reinforcing an alternative. Or I can make whining undesirable by telling her "No" or using a squirt bottle, etc. This would be correcting or punishing the behavior. Typically I will use a blend of the first two techniques, but for very persistent, ingrained habits I will sometimes use a mild aversive and then praise when the undesirable behavior stops.
So, is it fair to the dog to eliminate one of their ways of communicating? I would argue that the answer to that questions is both yes and no.
In the yes it is unfair to ask a dog not to whine column:
Dogs already have very limited ways of communicating that owners can readily understand
Whining can be a way for dogs to self soothe
Dogs use whining to communicate wants and needs
Whining is a natural part of a dog's repertoire
In the no, it's not unfair to ask a dog not to whine column:
Dogs can easily escalate whining to become non-stop and persistent.
Dogs often want things they can't have at that exact moment
Excessive whining can cause a dog to spiral into neurotic behaviors or panic
Just because a behavior is natural does not always make it appropriate especially at all times (barking, chewing, digging)
Looking at those lists, to me it becomes clear that whining as a tool for communication about a dog's essential needs likely serves an important function. However, excessive whining can be detrimental to both the dog and their humans.
The solution? Decide in which circumstances whining is okay and reinforce that behavior (by giving the dog what they want) only in those circumstances. This may mean you let the dog out the first time they whine at the door to go to the bathroom, but not the second, third, or fifth time in an hour. It could also mean when the clock strikes 7p you feed the dog when they whine, but when the clocks get set back an hour in fall, you don't feed them until the "new" 7p - that way your dog doesn't start eating an hour earlier half the year. When you don't want to respond to reinforce the whining use one of the strategies above: management, redirection and reinforcement of an alternate behavior, or correction/mild aversive.
For me personally, whining physically grates on me - it's often literally physically painful for me and can trigger my migraines. So I generally don't allow dogs to whine as a request for something because it's painful. I train alternate behaviors with boarding dogs and intentionally own dog breeds that aren't prone to whining.