Cat has had 15+ severe coughing fits since November (video)

My cat was born with a cleft lip and I dropper fed him until he was 2 months old, other than getting food stuck in his nose once when he first started eating on his own he hasn't had any sort of medical issue. In November he started having a severe coughing fit every few days with nothing ever coming up so I'm lead to believe it's probably not a hairball. If anyone recognizes what's wrong with him or can give me some insight on what to do I would be so grateful, I'm desperate to help my little buddy.

I visited a vet on Dec 18th but didn't have this video to show him, by my explanation he didn't think it was asthma and he said it was probably dust build up in his open nasal cavity causing him to cough like this. I doubted it because he didn't cough like this during the first 14 months of his life.

Did the Vet mention anything at all about his heart?  I don't want to scare you, and maybe it's nothing to do with his heart (I know nothing at all about clept lip in cats), but coughing fits in cats can be a sign of a heart condition.  One of our members (Carolina) had a cat with Congestive Heart Failure, and she posted this video of Gracie coughing, which was one of the signs of the disease:  http://www.thecatsite.com/t/239533/cat-cough-when-it-can-turn-out-to-be-a-sign-of-a-deadly-disease

The coughs are not quite the same as in your video, but it may help you non the less.  You might want to pm Carolina, although I believe she is moving today, so may not be able to respond right away. 

for your little guy

The vet I visited actually didn't mention a heart issue at all. I know he was born with a small heart murmur but the 2 times that he's been to the vet since last February the vet never brought it up again so I assume it never got worse or went away completely.

The vet acted like he didn't want to give him a chest x-ray when I bought him in last month when I brought it up, I should have just told him to do it though. I'll PM Carolina when I have some more time but if she's reading this post (first of all sorry about your cat) but how often did your cat cough? How long did each cough last? Cliff's coughs happen about every 4 days and last anywhere from 20-40 seconds each then he goes back to playing right after.

Thanks everyone for taking the time to read.