Bringing in another dog is a wonderful idea, but... you must make sure your daschund is dog-friendly. To test this, you can go to a dog park and see how your current dog reacts to other dogs.
You can also ask a friend who has a friendly dog, to bring that dog over to your house to see how the interact with each other. You'll want to set up the introduction in a safe fenced-in neutral territory, such as your back yard. Have both dogs leashed and slowly introduce them to one another. If there is any dog agression, stop the introduction at once.
If things are going well, you can drop the leashes so they can play with each other.
