Can gambling be a business?

We create more income from gambling that our other two businesses.  

Your other 2 businesses? The problem is you're going to have a hard time convincing the IRS that gambling is your business unless you devote a significant amount of time to it and even more than your other 2 businesses. You have to at least do this on a continuous and consistent basis and spend a ton of time on it.

Yes, there are such things as professional gamblers. 

A business activity (that allows you to deduct business expenses such as travel and losses) must be "an ongoing trade or business" that is pursued with a profit motive and doing such things as are common to this type of business (a contractor would be expected to advertise, for example). 

You would report your income on a schedule C like your other businesses.  You need a separate schedule C for each distinct business.

If you are in a partnership, you would report that as a partnership or as a qualified joint venture, as already discussed. https://ttlc.intuit.com/community/business-taxes/discussion/re-allocating-w-2g-s-to-a-schedule-c/01/2323524#M76403

You should probably see an enrolled agent for advice on proper reporting of your gambling as a business activity.  This is an area where you could be hit with big penalties if you get it wrong.