For small dogs, much of the world is vastly larger than they are including the places in our home they like to rest like couches and their humans' bed. While many small dogs can make the jump up and down to these surfaces, should they be? In my opinion, probably not, and it's not for the reason you might think... Allowing your dogs on furniture seems to be a highly controversial topic for reasons I can't really wrap my head around. Personally, my dogs enjoy free access to whatever surface they find most comfortable - including a blanket on my desk when the sun shines in the office window just right - because comfortable rest is not a privilege, it's a necessity. Plus, I have no problem with it; my home is their home. That being said, you should do whatever works for you and your household. As with all things, this issue isn't cut and dry - there are valid reasons to not allow your pets on furniture which I will not dive into here, but "needing to earn that privilege" has nothing to do with it.
Aside from your pet furniture preference, jumping up and down to and from tall objects repetitively opens up risk to injury over time. Jumping up can sometimes result in falls if your dog judges the height incorrectly. Jumping down places a lot of stress on your dog's front limb and back joints. Over time this can contribute pain, injury, or disease such as arthritis or intervertebral disc disease (IVDD), especially in small breeds with elongated spines such as dachshunds. Even if your dog is relatively young, all it takes is one bad incident to suffer long term consequences. For this reason, I recommend every small dog home has dog stairs or ramps for tall furniture.
When it comes to stairs or ramps, the earlier you start, the better. If you teach a puppy to use a ramp from the get go, it's more likely that that mode of access to your bed will become default. If you have an adult or senior dog, don't worry - it's not too late! You can teach dogs of all ages to use ramps and/or stairs. It just may take a little more time and effort to build the stairs/ramp as a habit for your adult or senior dog, but that time and effort is worthwhile.
Hopefully by this point if you (1) have at least one small dog, (2) your small dog is allowed on the furniture, and (3) you don't have a ramp or stairs currently, I have you convinced to go out and buy some. Before you do, you should know that unfortunately, many dog stairs and ramps aren't built for dog usability in mind. Instead, many products appeal to the human shopper, which makes sense since Fluffy doesn't have a credit card among other limitations. When looking for stairs or ramps, there are few critical things to consider:
Durability - The material should be durable enough so that it does not wiggle or wobble much or give when your dog walks up/down it.
Incline - Many products are far too steep for many dogs to comfortably use them. Senior dogs are particularly prone to muscle loss and steep inclines require more strength to go up and down.
Width - Consider how your dog or dogs, plural, will fit on the stairs/ramp. If looking at stairs, you will also need to consider if they are wide enough to comfortably navigate. Many pet stairs have very narrow steps which can be very difficult for our pets to use.
Height - For steps, consider how high is each step in comparison to your dog. For both ramps and stairs, consider if it is high enough to reach the surface you are looking to use it for.
Grip - Whatever material is used for the portion your dog will walk on should provide sufficient grip to prevent slips, trips, and falls.
Generally speaking, I strongly prefer ramps over stairs for taller surfaces like beds. For shorter surfaces like couches, depending upon the height and your dog, stairs are often more than sufficient. The product you find to work your dog, your space, and yourself might differ from the ones I would choose. However, based on all the aforementioned factors and much trial and error over the years there is one product I have found that performs above the rest: DoggoRamps.
While I am affiliate for DoggoRamps, know that I became an affiliate because of how much I genuinely love their product. It's not only aesthetically pleasing, but high quality and built with dog usability in mind. If you also find yourself wanting a DoggoRamp, you can use our code (EODT15) to save 15%.
In terms of stairs, DoggoRamp also has a step-ramp and couch ramp available. However, I currently use the PetGear Easy Step II (two step) version for our couch with great success with both of my pups. I have also used the three step version in the past for our bed, but found it was not comfortable for Ollie (13 lbs., Rat Terrier mix) and Gracie (22 lbs., leggy Russell Terrier mix) was finding them more difficult with age.
Regardless of what you choose, please don't expect that you purchase and set up the stairs/ramp and your dog will automatically use them. There is absolutely some training required and if you have an adult or senior with a history of using another means to access furniture, you will need to do enough training until the stairs/ramps became habitual. If you're looking for help on how to do this, check out my small dog class - we cover these topics and so much more.