My dog has a bad cough

Hi everyone.....if anyone can help me I'd really appreciate it.
I have a 12 year old Austrailian Shephard who lately has been "hacking" like crazy! It's almost like he's a cat trying to bring up a fur ball. He has multiple cysts that have been looked at by a vet and are ok.......however we do have to drain a couple of them with a needle on the monthly basis because they get so large. If anyone knows why he's coughing so much please help! He's my baby.
Thanks!
PS. He hasnt' been in a kennel or around other dogs other than my dads dog who is completely healthy and has also not been to a kennel.

I'd get in to the vet for a check - especially the heart and lungs, could be anything, COPD, CHF, etc - and definitely worth a vet check. Good luck!

Sorry can't help with the cough but would love to see a picture, I had a Blue Merle Aussie called Skylar. What a great bred this is love them, they are so smart :)

I would take him to a vet and get him checked for the above mentioned conditions (CHF in humans, if left untreated, can be fatal quickly... I'm not sure about dogs... but I would def. get him assessed for it.)
Also, even though he hasn't been around other dogs get him checked for Bortadella (Kennel Cough), from what I've been reading it is hard to catch outside of a kennel, or group dog area, but not impossible.... It is an airborn virus that has a side effect of making a dog suseptable to bactirial infections (much like the Flu in humans), it is also airborn, and young dogs, elderly dogs, and dogs with compromised immune systems can get it from less contact then a healthy adult dog would.
I hope your dog feels better soon. :)

Just like everyone else suggested, go to the vet. Is your dog on heartworm treatment? A cough can be indicative of many things, like CHF especially in an older dog, that may be treated. My concern is that or heartworm. Good luck. My 13 1/2 year old lab baby just died in our arms Friday night from renal failure. I have a good feeling you'll do better. Thanks, good luck and God Bless.