So last night, I went with my Aunts to take a look at a dog they were thinking of adopting. They did a trial run for a few hours and we walked the dog with their current dog, a shih tsu, and Vigo, my 6 mo old GSD pup.

The dog was a 3-5 female pit mix (even though they called it a lab/german shorthaired pointer at one shelter and a border collie/shar pei at the other!), seemed very sweet at the foster's home. A bit too hyper focused on their cats and I did not get to observe it with the foster's small dogs.

Appeared very relaxed on the walk, until stopping at a corner and like a light switch, it stiffened and made a go at my pup. (Don't worry, he was in absolutely no danger and the whole experience was great for socialization for him. A good lesson in "my mom is in charge and will handle this for me").

Personally, a dog that will act like that towards an obviously goofy, "slightly uncomfortable with the situation" puppy needs a lot more than what my Aunt could offer it. It also postured at every dog we saw while walking...she was a tough one to read, just a slight stiffening and her tail held slightly higher and tighter than usual.

Anyhow...this dog probably peed and scratched no less than 30 times on a 15 minute walk. Got to their house and it probably marked another dozen times in the ten minutes I was there. I have never seen anything like it!

I have never really had a territorial marker except my Cairn Terrier who we had a few problems with when we first moved in our house. I was pretty surprised that this dog in a brand new situation with brand new people would be so determined to claim the ENTIRE neighborhood.

Just struck a cord with me that I needed to learn more about this...anyone out there have experiences with a dog like that? How did you stop it? What other behavior issues were there, if any?

Sorry I can't help more directly with your question; but I did have to chuckle at your mention of Cairn Terrier = my son's dog "Bob" was prolific at marking, until he (my son) watched my pack structure video with me, & (my son) followed it to the letter, put "Bob" thru the paces!!
Solved the marking in the house problem that "Bob" had had to be crated for prior!!
"Bob" is a happy dog now, knows his place,& knows who the pack leader is!

Sounds similar to my 1.5 year male lab, who is very dominant. My trainer, an accomplished protection trainer, confirmed that he is a rare dog, an exteremely dominant lab. He is very confident and growls a lot when he encouters other dogs. I once took him to the dog park at midnight when it was empty. He was marking and growling non stop even though there were no other dogs around. It was insane.

This is a cut and paste from the Michigan Human Society.

Dominance Or Anxiety?
Urine-marking is usually associated with dominance behavior. While this is often the case, some pets may mark when they feel anxious or upset. For example, a new baby in the home brings new sounds, smells and people, as well as changes in routine. Your dog or cat probably isn't getting as much attention as he was used to getting. All of these changes cause him to feel anxious, which may cause him to mark. Likewise, a pet that is generally anxious may become more so by the presence of roaming neighborhood animals in your yard, or by the introduction of a new cat or dog into your household. If your pet is feeling anxious, you might consider talking to your veterinarian about medications to reduce his anxiety while you work on behavior modification.

Thank you