Animal fighting is illegal in some region because using life animals such as a donkey or other game animals to gamble is seen as unfair treatment to those animals and one can get a jail term for that, that is why this type of games are not popular modern days gambling.
In my country animal right is in the law and one can not just use cock or any other animal to gamble at will.
Not all countries have laws on animal protection except for endangered animals which are on the verge of extinction, which is why gambling using animals always exists even though it is done in secret not because of regulations regarding animal protection but rather gambling laws, but even if it is done in secret it is difficult to eradicate because the organizers will always have a way to re-hold the event because they will be able to make a lot of money they will try to keep holding it
Yes, just like in the country where I live, there are still many traditions of cockfighting gambling and it is indeed prohibited by the government because there is a law against gambling in any form.
However, there are many cockfighting gambling places that are guaranteed to be safe.
From the organizers themselves, they provide taxes to influential or authorized agencies to ensure this security and so that certain government Parliaments do not know about it.
Cockfighting gambling activities are actually used by unscrupulous government officials to profit solely from the tax yields provided by the organizers.