Depending on where your Dachshund plays and runs you need to bath every week or at least every 2 weeks.  You can bath more if you like with Wampum Conditioning Shampoo as it does not strip the sebum out of the skin and coat and restores skin barrier function.  Having an in-tact skin barrier protects your dog against skin allergies and skin reactions and also against pathogens that enter via the skin.