This is just a "RIDDLE"

There are four friends Barry,Larry,John and Mark they went to a restaurant the decided to play with their waiter they asked the waiter "which two of us are brothers" they gave the waiter these clues
-Barry is alergic to animals and lives in an apartment with his parents.
-Larry lives in a one storey house and live with his parents and either a brother or sister
-John's father has a disease of asthma.
-Mark is a veterinarian.
-The brothers have a pet dog named cuddles.
So who are the two brothers?