Updated September 25, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
Quick answer: Most respiratory infections in dogs, like kennel cough, are mild and resolve within 1–3 weeks with no lasting effects. They become dangerous when they progress to pneumonia, which is more likely in puppies, seniors, flat-faced breeds, and dogs with other health problems. Canine distemper and some strains of canine influenza can be severe. Prompt vet care for warning signs leads to good outcomes in most dogs.
Typical course
- Mild kennel cough: improves within 1–3 weeks
- Cough can linger a little longer as the airway heals
Complications
- Pneumonia: fever, lethargy, poor appetite, fast breathing. Treatable, but can be serious
- Chronic bronchitis in some dogs after repeated infections
- Distemper: can cause lasting neurological problems or death in unvaccinated dogs
Higher-risk dogs
- Puppies and seniors
- Flat-faced breeds
- Dogs with heart disease, collapsing trachea, or weakened immunity
Improving outcomes
- Vaccinate as your vet recommends
- See a vet promptly for warning signs
- Rest and humidity during recovery
Sources
- Merck Veterinary Manual: Canine infectious respiratory disease complex
- Lappin MR, et al. Antimicrobial use guidelines for treatment of respiratory tract disease in dogs and cats: ISCAID. J Vet Intern Med. 2017
- Merck Veterinary Manual: Pneumonia in small animals
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.