We were gone on vacation and left our dog in a very nice pet hotel where she was allowed to play with the other dogs. Three days after we brought her home she developed a very persistent dry hacking cough. I’ve given her some cough medicine and it helps for a short while but then she is right back coughing. She doesn’t seem ill since she eats and plays but the cough seems to be getting worse. What’s going on?
With the history and signs you provided my best guess, without examining the animal thoroughly, would be kennel cough (trachea-bronchitis, i.e. inflammation of the trachea and bronchi sometimes also called Bordetella). You need to get your dog to your veterinarian as soon as you can for a complete exam and workup. If she does have trachea-bronchitis and it is left untreated it could result in pneumonia and be life-threatening. There are other conditions that can cause this kind of cough and those need to be eliminated from the diagnosis.
Kennel cough is highly contagious, spread from dog to dog via airborne droplets breathed in a confined spaced, such as a kennel, or from direct contact with another animal that is infected, play dates, or even from contact with the causative agents on contaminated surfaces such as a communal water dish at the dog park. The etiology (cause) can be a variety of organisms viral, bacterial and most commonly a combination. Viral infections with the canine parainfluenza virus, canine coronavirus, canine distemper virus, canine herpes virus or canine reovirus make the animal more susceptible to infection with the most common bacterial villain; Bordetella bronchisptica (hence the other name Bordetella). This bacteria has been isolated in more than 75% of cases of this disease and is frequently found along with other opportunistic bacteria.
Most boarding kennels will not accept an animal without an up-to-date vaccination history and the vaccinations provided by your veterinarian will prevent this disease in most cases. However, like the flu vaccine for humans, vaccinations are not one hundred percent effective and some infections are a result of Bordetella alone. There are a few vaccines that are effective, long term, for bacteria but Bordetella does not seem to be one of them.
Treatment is with supportive care if necessary for dehydration, rest (pulling against a collar or heavy exercise will exacerbate the coughing) and cough suppressants. Antibiotics effective against the secondary or primary bacterial agent may be prescribed. Since Bordetella is by far the most common culprit your veterinarian may not bother with trying to culture and do an antibiotic sensitivity test to identify the best antibiotic to use, although this might be indicated in a persistent case. Most veterinarians will treat with the antibiotic or combination of antibiotics that have been most successful in their practice. Make certain you follow the directions and give the entire dose since we do not need more antibiotic-resistant strains of bacteria around.
The good news is that this disease, if properly treated, is usually not life threatening. You can expect the distress inducing (in you) coughing to decrease and go away within 3-6 weeks.