Thank you for the additional information.
If he is eating then this tells us that nothing is actually caught in the throat so I do not think this is something that you have to rush to the vet for today.
There are several possible causes for what is going on.
* Kennel cough- This will very often cause them to spit up a foamy substance after coughing. The incubation period for this is 5-7 days so it is very possible that he was exposed at the dog park.Click here
* Intestinal parasites- This can cause coughing as the worms migrate into the esophagus
* Infection or injury in the throat- If he chewed and swallowed any of the chew stick this could have scratched the throat.
This is not meant to be a list of all possible causes only the most common
For now you can try Robitussin DM to see if this helps with the cough. This is dosed at 1 teaspoon per 20lbs of body weight every 6-8 hours.
If the coughing continues for more then 3-4 days, he stops eating or declines in any way then I would have him seen by a vet.
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