Hi there, my BT Ozzy of about 3 1/2 months lately has been making a huffing noise (not like kennel cough) then follows is up like a loud hack noise (as to clear his throat). We keep him outta a lot of stuff from making him hack, but it almost sounds phlegmy with the huffing noise (jst mucus).
He also seems very lethargic as of late with this and wants to sleep on us as much as possible.
If anyone has a suggestion or have had this problem S.O.S plz let me know.

Bostons sometimes get very excited and make this loud sound as though they are going to throw up but nothing comes out. It sounds like this might be what your dog is doing. Although they're not lethargic afterwards, so I'm not sure.

Keep a good eye on him and see a vet if he shows signs of deteriorating, such as not eating or drinking or being overly sleepy or drowsy.

Good luck!

go to the vet. it could be epilepty. it sound asif he has a ceisure which will cause him to be lethargic. get him checked out this may need medication.

It is reverse sneezing which all short nosed breeds go through. The only reason to be concerned is if there is any discharge or labored breathing similar to a person with Pneumonia as it could be kennel cough. Whenever your dog starts making those crazy snorting noises, calm them down and talk to them very softly telling them to settle down. Then, cover their nose (I just use two fingers) so that they breathe out of their mouth. This should stop it but usually requires a couple times to get things better. You may find that calming down your dog will end up helping before you have to resort to getting them to breathe out of their mouth. If there is any discharge whatsoever from the nose, please take your dog to the vet. Please keep us posted!