puppy with cough

[RED BRUSH KENNELS]

the pup is 3 1/2 months old he coughs like a dog that has kennel cough but i have him in the pen with his littermate brother and he dosen't cough.he has been wormed several times and has had all his shots.this has been going on for about a week to two weeks.he still eats good and drinks plenty of water.he still has plenty of energy and play.any help would be great.thank you

[ringtail]

put about a half a cap of bleach in his water everytime you fill it up this should take care of it in about a week or so