EDIT : Added white-space: normal
on dt
You issue may come from your container.
You can use a .panel
class with a fixed width to get it work.
Consider the following:

<div class="panel panel-danger">
<div class="panel-heading">Baseline <span class="pull-right">ERROR</span></div>
<div class="panel-body">
<dl class="dl-horizontal">
<dt>Description lists</dt>
<dd>A description list is perfect for defining terms.</dd>
<dt>Euismod</dt>
<dd>Vestibulum id ligula porta felis euismod semper eget lacinia odio sem nec elit.</dd>
<dd>Donec id elit non mi porta gravida at eget metus.</dd>
<dt>Malesuada porta</dt>
<dd>Etiam porta sem malesuada magna mollis euismod.</dd>
<dt>Felis euismod semper eget lacinia</dt>
<dd>Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus.</dd>
</dl>
<div class="btn-toolbar text-center" role="toolbar">
<button type="button" class="btn btn-primary">Expandable</button>
<button type="button" class="btn btn-primary">ERROR <span class="caret"></span></button>
<button type="button" class="btn btn-danger">Delete</button>
</div>
</div>
</div>
.panel {
width: 500px;
}
.panel .dl-horizontal dt {
white-space: normal;
}
Bootply