Merlins new and distrubing behavior

Merlin had an aggressive barking problem when he was 2. After having him netured he was fine till now. This came to my attention this weekend, but my daughter said he did it to her a couple months back.
We went to Idaho for the weekend the neighbor that he LOVES was to let him out to potty and then let him back in as with lady. Well the first night he barked very aggessively and started to growl. She discribed the growl (it sounded like his leave me along ) but with the barking she was a little concerned. So she left him in and went to let her dogs out ,He was still barking a half an hour later. So he didn't get a last out. The next morning he did it again , so she decided to try petting him so she sat down and pet him. He still growled but not barking, so to get him out she rembered his treats and lured him out side with one and gave it to him outside. She had to do this all weekend. What do you all think and what can I do for this , I can't make my son stay home to watch him all the time and I can't have my daughter do it couse one day I was shopping and she came to drop off something(son was sleeping in his room and didn't hear her) She said he did the same thaing to her, she just left ( shes not crazy about him any way.) Suggestions ????

Corinna,

I really have no idea. How often is your daughter around
Merlin? Maybe he senses her fear/distrust of him. I sometimes
let my neighbor lady look in on Buddy (in my house) if I had to
go out of town, but Buddy knew her face & her voice. He always
barked very loudly if anyone came to the door, so I told her to
always call out his name & be talking to him when she opened
the door. (No surprises for either of them). He wouldn't eat when
I was gone, but always when out to do his business,etc., just
fine. Buddy was very protective of his house, but not aggressive
with people. If I accepted them, so did he. Is Merlin like that?

No this was something else, Merlin has known Storm( the neighbor) since he canme to live with us 7 years ago. In fact normally he gets more excited when she comes home than when I do. He has a window he can see her pull in. The thing with my daughter I don't understand either she always yells out asking if any one is home, then calls his name too. This all started about 4 weeks ago, iI can't think of anything that has changed or happened to cause the change.

You might want to get him checked by a vet or specialist. Have them do an MRI or some kind of brain scan to rule out tumors. Is he current on all of his vaccinations: rabies, distemper?
If he checks out clear of any medical problems, try having him evaluated by a professional behaviorist.

A few of my dogs while in there cages will bark and growl at my relatives that come for a visit when they haven't been there for a while, but the minute we let them out of the cage it's a totally different personality.

This could be a really tough one without seeing the situation. I don't think this a "new" behaviour but something the dog is re-discovering. The fact that he could be the boss with your daughter when she came to let him out - remember the dog is trying to do his job when the real boss (you) is away by protecting the territory - and got rid of the intruder has reinforced it. It is the whole postman/van (mailman) thing really - some dogs go nuts when the post arrives simply because when they bark and growl the postman goes away (it doesn't matter to the dog that the postman will go away whether they bark or not) so it is a rewarding behaviour as what the dog wants to achieve actually happens and the dogs feels that it has protected it's territory well.
It will take a great neighbour or a fab daughter to overcome this - not fair on a daughter who has made her feelings clear already, I feel! If the neighbour is willing, however, then progress can be made. Start with the neighbour calling to let the dog out when you are in the house, the neighbour could take the dog out and go through simple excersises like "sit", walking to heel, "stay" and come. This will establish some respect and status. Then try it with you out of the house but close by so if things go wrong you can simply walk by, say "Hi" to the neighbour and ignore the dog - then he will know where you think the pack structure lies.
If your neighbour isn't up for that then you may have to look further afield for someone to do this for you.

I think it’s natural for a dog to bark at people that he doesn’t know. Strangers. You wrote that your daughter isn’t really crazy after him, so I guess that he feels that, and that’s the reason he acts like it.
Emm… and the same as for your neighbor: he doesn’t really know her, his owners were gone, so he was protecting himself. After all he is a dog, not a person. I doubt he understand things like where you, the person who take care of him is. He probebly felt alone and confused because all of the sudden another lady was taking care of him.
Who can blame him??

I agree w/ carrie.
A professional behavorist may be of some help too.

Good luck!