I am not a big fan of Dogecoin, and believe that it is having very low acceptability. Also, it is not very stable or mature, to be used for gambling purposes. Security is another issue with Doge. I would rather go for coins such as Bitcoin Cash or Tether (USDT). Ethereum is also a good choice, but it has some security issues. So storing them can be a hassle for the gambling sites.
Next to bitcoin, Ethereum and Doge are mostly used coins on gambling sites.
I use to roll the dice on windice and frequently I can see this Doge has been used many times. So we can find this coin might be used many times next to BTC.
Still Bitcoin is growing everyday with and without help of gambling industry.