So I have a dachshund mix, Brandy, (the "dachshund" part is very visible and she's often mistaken for a purebred, albeit an unusual one, but we did DNA test her and the test suggested she is part black&tan coonhound also. Regardless, she's fairly large for a dachshund type of dog, about 26 lbs, and a lot of people are often intimidated by her.) We've had her for a long time and socialized her from a young age but we've noticed over time that she has started to develop more and more fear aggression towards dogs and people. We've even hired a dog trainer to work with Brandy, and she said that it was most likely "in her nature" to act like this, and that there was only so much the trainer could do.
She's generally okay with women and female teenagers; she'll just bark for a second or so and then by the end of the half hour she's letting them walk up to her, sit next to her, and pet her. If these people come often enough, she can become enamored with them and greet them as they enter the house. However, for whatever reason, she can't seem to get over her fear of men.
It doesn't matter how big, tall, or "scary" the man is. Regardless, she can seem extremely aggressive toward them--in the worst case scenario, snarling, lunging at them, and barking. With the sounds she makes, in the worst case, it almost sounds like a dog attack, but from about a 3 feet distance from the person. Once, a man came over with his wife and he stayed for almost 3 hours and although Brandy stopped barking eventually, she sat down on the couch right next to him and though seemingly relaxed, I suspect she was only keeping an eye on the man. Every time the man shifted or stood up, she would bark at him all over again. She never once became at ease with the man. However, she has never bit anyone even once in the 8 or so years we've had her. She's just very afraid of certain people. We've started putting her on a leash when men enter the house to limit her contact and be able to train her more easily, and it has made some difference but not as much as we would like, and she's still very much afraid, and we really don't want to chase off guests who come to visit.
As for children, she's better with them than men but has a problem of "snapping" at them. She is often very nice to them after barking at them for a minute or so when they walk in, and will lick their hand and be pet. However, if they make one "threatening" move, she gets right in their face and barks vigorously at them. This has happened on 3 occasions.
First occasion: A girl, about 9 years old, was running past her. Brandy must have assumed that she was running TOWARDS her, and she started barking out of "nowhere".
Second occasion: The same girl jumped (literally--with a running start) next to me on the couch and Brandy put her face right in the girl's and barked almost hysterically at her. We're not talking a little "yip yip", but a bug-eyed, adrenaline-filled, almost yelping bark.
Third occasion: A different girl, about 10, was petting Brandy a couple minutes after she had entered the house. Brandy was licking her hand and allowing the girl to pet her although Brandy seemed a bit bug-eyed and nervous. The girl leaned in closer (and very slowly) to Brandy's face, probably hoping to get a kiss on the cheek, and Brandy pulled back and started barking in the girl's face (the girl was very upset by this, almost tear-eyed).
I understand that this is NOT acceptable behavior from a dog. However, Brandy is an excellent dog in every other way and we really want to find a way for her and our guests to be comfortable with each other. Is there any recommendation for how we can keep Brandy from being so afraid of men and children who come over, and from barking at them when they exhibit "threatening" body language? How can we make Brandy feel more comfortable?
Thanks so much!