Hi

My 9 month old chihuahua has just started to mark things around the house, if I leave anything lying unattended for a few minutes it has been marked. (esp bin bags at the moment)

He is house trained and always goes outside to the toilet except if I let him come upstairs with me at night. He seems to get confused at does it near the front door.

So I am almost 99% sure that he isn't weeing and rather marking as when he does it in the house he cocks his leg, but he doesn't do this when he is in the garden.

There is no other dogs in the house except a 10year old female cat.

Can anyone help me ?

Thanks

Sarah

Neuter him now. It is not a cure all, but does help reduce marking and other problems. It absolutely does prevent passing on tendencies toward marking. Then take over as top dog. Take him as seriously as he takes himself.
Having a good pack structure reduces such problems. The dogs see all the
People and dogs in the household as a pack with each having their own rank in
The pack and a top dog. Life is much easier if the 2 legged pack members
Outrank the 4 legged ones. You can learn to play the role of top dog by
Reading some books or going to a good obedience class. A good obedience class
Or book is about you being top dog, not about rewarding standard commands with
A treat. Start at http://www.dogsbestfriend.com/.

In our modern society, even if we are home,
Other things distract us from the attention an uncrated puppy must have. The
Only real solution is to crate the dog when you can't watch it. The dog may be
Happier in its den than loose in the house. It relaxes, it feels safe in its
Den. It rests, the body slows down reducing the need for water and relieving
Its self. Dogs that have been crated all along do very well. Many of them
Will rest in their crates even when the door is open. I think the plastic
Ones give the dog more of a safe, enclosed den feeling. Metal ones can be put
In a corner or covered with something the dog can't pull in and chew. Select
A crate just big enough for the full grown dog to stretch out in.

Leave it some toys. Perhaps a Kong filled with peanut butter. Don't leave
Anything in the crate the dog might chew up. It will do fine without even any
Bedding. You will come home to a safe dog and a house you can enjoy.

A dog that has not been crated since it was little, make take some work.
Start just putting its toys and treats in the crate. Praise it for going
in. Feed it in the crate. This is also an easy way to maintain order at
Feeding time for more than one dog.

The "shut the puppy in a safe room" is a fallacy. Very few houses even have a
Safe room. How many of us have a room with a hard surfaced floor and nothing
Else? Most rooms have electrical cords to chew if nothing else. In addition
To destroying anything a bored puppy finds to chew, it may choke or have
Intestinal blockage from the pieces. I had a friend that left her dog in a
"safe" room. It ate a hole in the floor covering. The safe rooms fail to
Give the dog the comfort of the enclosed space their instinct requires. Nor
Do they restrict activity extending the time the dog can go without relieving
Itself.

Catching him in the act of marking calls for stronger corrections than the
Otherwise effective "Bad dog!". When it misbehaves, throw it on its back, and
Growl "Bad dog!" right in its face. Hold it down until it lifts one back leg
To show submission. You can pick him up with your hands behind his front
Shoulders and hold him up with his back to you. Keeping him far enough away
To keep his head from smashing into your face, hold him until he stops
Struggling and relaxes. Others like the squirt bottle. Fill it with water
And a little vinegar or lemon juice. Give it a squirt in the face as soon as
It misbehaves. Dogs hate that.