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Jane Lefler
Jane Lefler, Animal Behaviorist
Category: Dog Training
Satisfied Customers: 19666
Experience:  Behaviorist /Trainer and Dog breeder 18+ years
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I have a rescue Terrier who is 8 3 months years old. I got m

Customer Question

I have a rescue ***** ***** Terrier who is 8 3 months years old. I got him 15 months ago at age 7 from the Humane Society. He is a great dog, but has a couple of behaviors I would like to get some help with. First and most important is the protection/territorial aggression he is exhibiting. I had a blood test done at home recently for a life insurance policy, and as the paprmed was getting ready to draw blood, he snapped at her. This happened again when somebody was giving me a massage, and finally, and the third strike, my 9 month old grandson was at my house visiting today, and he made an aggressive move towards him. That is the aggression I need help with. The second trait he exhibits is a separation anxiety. If I go to the store, he goes nuts. He seems fine Monday through Friday morning when I leave for work, but any other time I need to go out, he goes crazy and will not stay, trying to get out and not obeying the stay command.
Submitted: 1 year ago.
Category: Dog Training
Expert:  Jane Lefler replied 1 year ago.

Hi JaCustomer,

My name is ***** ***** I’ve been involved professionally with dogs in the health and behavioral fields for over 18 years. It will be my pleasure to work with you today.

In order to supply you with an informed answer, it is necessary for me to collect some additional information from you. When I receive your response or reply, it will likely take me between 30-45 minutes to type up my reply if I am still online when I receive notice that you replied. I hope you can be patient.

How much obedience training have you done with him?

Not just giving commands but training with him?

Does he sneak up on the person when trying to nip?

how often do you walk him?

Expert:  Jane Lefler replied 1 year ago.

I was hoping to get a response back but I don't want you to go without an answer either. Let me go over the aggression first.

There can be medical reasons for sudden aggression so I need to mention those. Anything causing pain can cause aggression but also hypothyroidism can cause aggression as well. Read more on this here:

If there is no medical cause for the aggression, then it is strictly behavioral. Dogs are aggressive toward people for a variety of reasons. It might be that they are fearful of people and thus are aggressive before the person can be. In other cases, a dog is aggressive in order to dominate the people. Other causes could be that the dog feels they are the alpha member of the pack and as the alpha member they must protect the pack (you) from threats (people).


In addition, owners sometimes make the situation even worse by tensing up and worrying about what will happen. The dog senses the owner worry and feels that he is justified in his aggressive stance because you are obviously worried about the people. They don't know that you might be worried about something else like a needle stab, or the dog's behavior or even worried that your grandchild might be bit or have an accidetnt. They just pick up on the worry and feel justified in being aggressive. So it is important that you not worry.


For a dog like this, total control is necessary. This means not only physical control but on a mental level, you must be the boss. To accomplish this, you will need to have the dog wear a basket muzzle anytime you feel he may react and when your grandson is aorund.. This will not only prevent bites but also allow you to feel more at ease when strangers are around. You should use this until you feel comfortable with him around people again.


You will need to obedience train him. If you can, I would do group classes and let the trainer know of the problem your dog has.. Before you can get into classes, I am including a site that is helpful in helping owners train their dog. Be sure and click on the link to the page on obedience at the bottom. and links on subsequent pages leading to detailed instructions.

The following site is helpful. Be sure and click on the link to the left on obedience. and links on subsequent pages leading to detailed instructions.

Training works best if you train at least 30 minutes a day (two 15 minute sessions). I would start making your dog work via the Nothing in life is free program (NILF). It is outlined below.


This obedience work establishes you as the boss and as the boss it is your job to protect the dog and not the dogs job to protect you. Now the dog will still protect you if something should happen because you will be protecting yourself and as part of the pack, he will follow your lead and protect as well. But if you are calm around someone, he will see that you are ok and there is no need to help. This is why being the boss works well. He may be very well behaved but that doesn't mean he sees you as the boss, it just means that he wants to do what you are asking him to do perhaps because he gets something out of it. With repetitive training, dogs become a little bit more submissive each time they obey a command even if for treats. Eventually they just obey without really thinking about it.


You will also want to keep a leash on him at all times initially to grab if he should disobey. I think you will be pleasantly surprised at how well your dog does with training. Dogs like knowing what is expected of them and they love the little paper thin slices of hotdogs that I use for treats while training.

It will be helpful if you can find someone to help you once you have your dog listening to commands consistently. What you will do is have your dog on the leash. You will have your helper come in. Your helper will gradually move closer to you preferably walking past you initially. As long as your dog ignores them, you can give your dog praise and a treat. The second you see him fixate on the person or show any other sign of aggression (hair standing up, etc.) give your dog a correction by giving a short tug to break his concentration and a firm low toned "NO". It shouldn't take your dog long to realize you will not tolerate the aggression and that if he ignores the person, he gets treats. Once this happens you can repeat the training moving the person closer until he is no longer trying to lunge at people.


In addition, if the situation is not improving using the techniques on the previous website, you may have to consult a professional behaviorist. You can usually find a behaviorist by asking your Vet for a recommendation or you may be able to find one using the following site.


Unfortunately, at this point, I would seriously consider having a behaviorist anyway available to evaluate the dog and determine the aggression level. In the meantime, institute the techniques I have recommended.

Now for the separation anxiety I have a few suggestions. I should mention that it might just be your dog manipulating you. He is fine when you go to work but he also knows about when you will return and likely he can't convince you not to leave or to take him with you when you leave first thing in the morning. You likely dress different for work and leave about the same time every time. So it may just be him trying to manipulate you into staying or taking him with you.

There are some things that can be done. First thing is to take your dog for a nice long walk before you leave, preferably 30 minutes or long. Make it a long, quick paced walk to tire your boy out. Another one is to use a low-key approach to leaving the house. Ignore your dog before you leave and after you come home for at least 5 minutes or more.

You can provide him with small stimulating toys or toys that you can fill with treats. Fill kong toys with yogurt or meat baby food that doesn't contain onion or garlic. Freeze the whole thing and give right before you go out. It will keep him occupied for hours. Remember not to reward any unwanted behavior by trying to reassure your dog. You want to show him nice calm praise when he is being calm.

One thing that might help is a DAP collar. These use a pheromone to calm a dog. See one here:

Training can help as well. Practice leaving the house, opening the door immediately and rewarding him with a hot dog treat if he did not scratch, bite and carry one. This teaches him that you leave but come back quickly. Once he seems to not do anything when you initially leave, lengthen the time he must be quiet for you to come back in. Change the time as well. Make it 2 minutes one time and 10 mintues another, so he never knows if you are gone for an hour or gone for 2 minutes. It helps him stay calm for longer periods of time, just be sure you reward him when he is good.

Another thing that helps is to do things that might make the dog feel you are leaving and then don't such as putting on your coat or picking up your keys. Or leave without doing those things. This helps remove things that might trigger the dog to become anxious.

These should help his separation anxiety and boredom. It will not be an overnight cure and will take work on your and your family’s part to be consistent in your interaction with him. Here is a site that also offers idea to combat separation anxiety.

Another option is medication, which is discussed on this site:

I hope this information is helpful to you. If you would like any additional information or have more questions please don’t hesitate to press the reply to expert or continue conversation button so I can address any issues you still have . If you do find this helpful, please take this opportunity to rate my answer positively so I am compensated for my time.

If you have questions in the future that you wish me to answer, you may click here and bookmark the page or make it a favorite. It is best to put my name "JANE" in the question as well.

Expert:  Jane Lefler replied 1 year ago.

Just a quick follow up to see how things are going with your ***** *****. Did you find any of my suggestions helpful?

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