My 1 year old son has a cough/running nose for 3-4 weeks, but no fever or other issues. today he was wheezing when he was walking. what should we do?

Asthma or allergy: This could be an allergic problem now going into asthma. Allergies at this age are more often food allergies and the commonest food allergy is cow's milk. Did you breastfeed and now have switched to cow's milk. Is there allergy in the family history. You need to see your doctor to sort this out as other possibilities exist. If it is allergy then an allergist is your specialist of choice.

Wheezing: You need to take your child to your doctor to get him checked. He can have a cold that went down to his lungs or he could have RSV bronchiolitis.