I am very sorry to hear that this has happened to Turbo. I would suggest the following;
Turn a bathroom into a steam room by leaving a hot shower in for a few minutes? Then bring into the bathroom (not the shower) Turbo so he can breathe the steamy air and help his airways.
place a humidifier in the room that Turbo sleeps in
Use a harness instead of a throat collar
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Robitussin can be used to help alleviate coughs, here is the caveat: there are many conditions that cause coughing in dogs, and infectious tracheobronchitis and collapsing trachea are only two of them. Dogs should not be given over-the-counter cough suppressants unless serious conditions like pneumonia, heart disease, and lung cancer have been definitively ruled out by your veterinarian.
https://www.petcoach.co/article/6-human-medications-that-are-sometimes-safe-for-sick-pets/I hope this helps and that you two stay safe!