Do I have a chance to take my roommate to court for his dog attacking me?

I would call animal control, which will enable you to both report the attacks and have the dog at least temporarily removed. You should also notify the landlord and your renters' insurance company. Beyond that, your roommate is liable for harms caused by his dog. That includes physical and emotional trauma, wages for missed work, and any other expenses and lost income associated with the attacks. A local lawyer who handles personal injury or dog bite cases should be able to help.

First: I would get you and your child away from the dog!

Second: You and your child can sue, probably get a judgment, but that does not mean that you can collect anything. Many personal liability insurance policies (but not all) exclude members of the insured's household. A lawyer would need to review the policy to determine if the claim is excluded.

If the dog owner is uninsured or the claim is excluded, a judgment is a hunting license for a sheriff or process server to seize non-exempt property and sell the property to apply the proceeds to the judgment. In Kansas, it is possible for a multi-millioniare to be judgment proof (have their assets set up so they are all exempt or additional collateral for loans against exempt property which must be paid off before the lien creditor can sell the exempt property [see Sproul v. Atchison National Bank, 22 Kan. 336 (1879)]).