Thanks for the question
While I cannot diagnose this via the internet I can tell you the following :
In direct answer to your question : This sort of thing is always a gamble, if you want to be sure you are doing the right thing you should have a vet examine your dog without delay. However I can tell you the following :
I would not be at all surprised if your dog has not contracted an infectious respiratory disease such as kennel cough, there is very little else this is likely to be in your dog's age group though of course other diagnosis are possible. If this turns out to be the diagnosis then though uncomfortable for your dog this is very rarely a serious situation and it is often regarded as a trivial disease.
Since kennel cough
would be a front runner I will concisely tell you what I know about it ...
Kennel cough is a common contagious respiratory disease of canines. This disease is usually associated with recently having been in kennels or having been where dogs congregate, but dogs living on their own can sometimes catch it as well as it is an airborne disease.
This is a disease which vets will see quite a lot, we often have to explain the symptoms to clients :
1. Most owners whose dog has kennel cough think there might be something stuck in the throat due to the strange cough / retch that these dogs have - a bit like a seal honk!
2. The dog may sneeze a little but the cough is the main symptom, some dogs are quite bright and alert but others can be lethargic during the course of this disease and runny eyes
are a possible symptom as well.
3. The dog will cough and retch for a few minutes and in the end it will be productive, he will bring up some white sputum, some owners take this for vomit. Once he has done this he will settle down for a bit. This however is a repeated cough which just keep happening.
4. It is normally not a serious disease but will run its course given one to two weeks without treatment, however antibiotics will speed up recovery and make your dog feel better very quickly.
Here is a link for more information on this disease : LINK
If I have not answered your question fully enough or if you would like to ask more I will be on line for the next hour or so and I will be pleased to discuss your question further.
Scott Nimmo BVMS MRCVS