The only problem with gambling with a loan is that if you lose the first bet, there is no way to repay the loan. If he is unable to repay the loan, he will be forced to take additional loans.
Never gamble with loans. You can't be sure that you will win. If you gamble with loans, you can't be sure that you won't lose money. If you lose the money gambling then you will realize how wrong decision you made by gambling with loans.
The wrong decision starts from conceiving the idea of taking a loan to gamble. No matter the outcome of the bet, regardless of your winning, it is still a wrong decision. Taking a loan to gamble increases the stakes, and if the individual loses, he will be left with a debt. If the gambler struggles to pay back, he might involve himself in missed payments, or defaulted loans, and this will affect his credit score.
When an individual takes out a loan to gamble, they are creating problems in their lives. If they lose the money they borrowed, they may be tempted to take out another loan to try and recoup their losses. This creates a cycle of compounding debt that can be difficult to escape from. The gambler will be in a situation where he owes more money than he can realistically pay back. He might end up selling off his properties to pay back loans or working without getting paid since his salary will be used for paying back the loans.