I think both my dogs got their kennel cough immunization by 6 months. They go to doggie daycare, the park, and to the groomer, so it was a must for us. Some vets do the vaccine, some do nose drops, it just depends on your vet-they have reasons for their preference. Give your vet's office a call and ask which way it is administered, and what the recommended age is to have it. 14 weeks is pretty young, but I'm sure they will offer it to you at his next scheduled appointment for shots. You can always call and ask