Dealing with Tangles and Mats
Removing mats and tangles involves both finger work and combing. Begin by breaking apart the mat as best you can with your fingers, working carefully so as not to break any hairs, if possible. Grasping the dog's hairs closest to the skin (to prevent unnecessary discomfort from your pulling), begin combing with the widest-toothed comb you have, or a special comb for removing mats. Work the tangle out from the ends of the hairs first, gradually separating and combing your way closer to the dog's body. Once you're able to clear the tangle with the wide-toothed comb, proceed with a medium-toothed and then a fine-toothed comb.
The most time you can expect your dog to keep still for this work is thirty minutes. If your dachshund is horribly matted and you can't finish the job in one sitting, try to work on the coat over several days, or take your dog to the groomer. The groomer will likely ask to cut down your dog's coat. Don't be ashamed to agree to this. The dog's coat will grow back, and trying to detangle and unmat coats that have been neglected is very painful to the dog and something you don't want him to have to experience.