I have always had luck with Teramicine. I'm sure the spelling is not right but I get it here at the feed store. It's an antibiotic that comes in a powder package, I put half the package into 2 to 3 gallons of water. Let them have that as their drinking water and change it out ever couple days usually the cough is gone in a few days.

1/2 cc of Tylan 50 a day for three days. Tylan 50 is a respiratory antibiotic. You can get it from any Tractor Supply store or Jeffers.

Depending on the wight of pup 250 mg of ceflex three times day and cough tab three times day

tylan works good as well as treating their drinking water with sulmet, you can get it at southern states or online, it is for respiratory problems in chickens but will kill the bacteria that causes the cough and will keep it from spreading thru the kennel. just a couple capfuls in 5 gallons of water, make sure you keep water there as it has sodium in it and will make them drink, sulmet also good for prevention of coccidia in pups and dogs, wayne