With sports betting, you get the odds in place when you make the bet. No so with horse betting. The odds change and you're correct, the house can never lose. The track's cut is very high compared to the vig on sports betting or casino games. I have partial ownership in a few race horses. One is racing tonight and I hope that he does well.The one thing I believe the "house" never loses is with horse racing, which I've seen in legal casinos. I'm not sure how it works with online horse racing. I was under the impression that all these tracks, offsite betting locations, and casinos pooled everything together where it's parimutuel and the odds aren't final until bets are closed. And there's a certain cut that goes to the track where the race takes place. And I believe the "house" is not allowed to lose by most laws that allow parimutuel betting.
It might be different for other racing. Betting isn't legal in Islamic countries, but it's possible to bet on horse racing competitions there internationally. That must be closer to other types of sports betting.
Well, the only way the house can lose money on horse racing is there is a minimum payout at $2.10 on a $2.00 bet. So, if all the tote was on the winner, the track would lose money.