3 Drops of hydrogen peroxide with 1 teaspoon of manuka honey on a little piece of bread stopped my 15 week old puppy coughing straight away.
He coughed 3 times the previous day just after he barked. I thought he was barking in a way that was bothering his larynx. Then come bed time he had some dreadful sounding honking. rasping, choking coughs.
I brought him to the vets first thing just to be sure he was ok. Vet confirmed it was kennel cough and no treatment was needed. (so glad they stopped giving out antibiotics willy nilly)
I came home and tried the peroxide remedy and it was like a miracle. I am astounded at the swift difference. The vet said he may well get worse before better but all he did was get immediately better. No rasping or rattling that night. He coughed quietly the next day once for two seconds. Today he has no symptoms.
I gave him 3 doses about 10 hrs apart. Do try this remedy it's fantastic.
Thank you so much to the person who originally posted it.