Coughs are caused by a variety of things in dogs. It typically sounds like they are gagging or trying to clear their throat (similar sound to a goose honk).
If the cough persists for more than a day or is accompanied by other symptoms such as not eating, lethargy, weight loss or difficulty breathing, your dog should be seen by a vet as soon as possible as these are often signs of something serious.
Infectious coughs are a common cause, and they tend to get worse before they get better. Vaccination can help reduce the severity and duration of the infection but won’t necessarily prevent a dog from getting a cough. Infectious coughs are most often self-limiting and resolve without medications, but they can also become complicated and develop into pneumonia – in which case they will need extensive veterinary medical care.
If you are ever concerned about your pet and they have a progressive or persistent cough, it’s best to contact your vet to assess the situation and make them as comfortable as possible in the meantime.