Cats harming son.

Patient: This qs is about my son who is not even one year old.actually our neighbors have a cat and their house is just few steps aways from our house, we share a same corridor you can say. so the problem is that they let their cat out in the corridor and on the terrace.their is history of asthma from my husband’s side.once the cat even entered our house and i think that the cats pees and poops on the terrrace which comes down through the stairs during rains and my door is just besides the stair. so i am afraid that the presence of cat can cause asthma or some other disease to my son.the corridor stinks of cat scent and i am worried about the cat’s hair. please help to take necessary steps