I was told today that Dachsuns are subect to back injuries. I have a two year old and I am concerned for my dog and want to know nif that is true and if it is what can I do to prevent this from happening.

You basically can't prevent this problem as it is genetic in nature. You could ask your vet if they recommend any type of calcium supplement for this.

Yes dachsunds are prone to having back problems. Not every dog will have them, but the risks are high. You can help prevent it by instead of letting your dog jump down from things, to put it on the ground when it wants down. If it sleeps in bed with you I recommend a ramp or stairs for easy access. If your dog seems to be having any issues now with pain I recommend seeing your veterinarian. You vet can also help you with medications that may help prevent problems.

Yes, dachunds are prone to back problems. Breeding has a lot to do with whether they have bad backs but there are things you can do to prevent or lesson the problem. The number one thing you can do is to keep your pups weight down. Ask you vet what weight is the best for your dog and keep it within a couple of pounds of that weight. (Example: If you have a miniature dachs, her weight should be no more than 10 pounds. If she weighs 24 pounds, she will definitely have back problems!)
And, as was mentioned, not letting him/her jump up onto or down from high places. Get a couple of doggie ramps for areas she likes to get up on and teach her to use them.
Those two things will go a long way to keeping your doggie's back healthy and strong. Good luck. We had our mini dachund for over 18 years and she never had any problems with her back.