BTC38 is counted for volume on CMC, you can look at DOGE for example that is their primary source for volume. I have requested CMC to add the new BTC38 DASH/BTC pair to our stats. Hopefully they do that soon.
Before CMC can add them, BTC38 has to provide DASH data with their api, I guess. At this time it's missing
http://api.btc38.com/v1/ticker.php?c=all