Most dogs with kennel cough recover within two weeks, and you should see noticeable improvement within the first week of starting antibiotics. That said, not every case of kennel cough actually needs antibiotics, and the timeline depends on whether your dog has a straightforward infection or one that’s turned more serious.
The Typical Recovery Timeline
After starting antibiotics, your dog should be clearly improved, if not fully recovered, within about a week. The characteristic honking cough usually softens and becomes less frequent during that first week, though it may not disappear entirely. Full resolution of symptoms generally takes one to two weeks total.
If your dog isn’t at least partially better after one week of treatment, that’s a sign something else may be going on. The infection could have progressed deeper into the lungs, or the cough might be driven by a virus that antibiotics can’t touch. Either way, a lack of improvement after seven days warrants a call back to your vet.
Why Some Dogs Get Antibiotics and Others Don’t
Kennel cough is usually caused by a mix of viruses and bacteria working together, but the viral component drives most cases. Because of that, antibiotics aren’t warranted for every dog that comes in coughing. Veterinary guidelines from both AAHA and ISCAID recommend reserving antibiotics for cases where a secondary bacterial infection is suspected or the dog is at higher risk for complications.
Dogs in shelters, puppies, senior dogs, and those with flat faces or pre-existing respiratory issues are more likely to develop bacterial complications. If your vet prescribed antibiotics, they likely saw signs that your dog’s immune system needed help fighting off a bacterial layer on top of the viral infection. For otherwise healthy adult dogs with a mild cough and normal energy levels, the standard approach is supportive care alone, with the same roughly two-week recovery window.
What to Expect During Treatment
The two most common antibiotics prescribed for kennel cough are doxycycline and amoxicillin-clavulanate. Both are given by mouth, typically twice a day. Your vet will determine the course length, but expect to give the medication for the full prescribed duration even if your dog seems better before it runs out. Stopping early can allow bacteria to bounce back.
During recovery, keep your dog’s environment calm and comfortable. Stress, extreme temperatures, poor ventilation, and inadequate nutrition can all increase the severity of symptoms and contribute to relapse during the healing period. Use a harness instead of a collar on walks to avoid putting pressure on the throat, and keep exercise light. If the cough is persistent enough to disrupt sleep or eating, your vet may also prescribe a cough suppressant to use alongside the antibiotic. Cough suppressants are not appropriate, however, if the infection has moved into the lungs.
How Long Your Dog Stays Contagious
This is the part that surprises most people. Even after your dog looks and sounds completely normal, they can still spread the bacteria to other dogs for a long time. Dogs carrying Bordetella, the most common bacterial culprit, can shed the organism for two months or longer after symptoms resolve. Starting antibiotics doesn’t instantly flip a switch on contagiousness.
Most vets and boarding facilities recommend keeping your dog away from other dogs for at least two weeks after symptoms clear up, but the true shedding window can extend well beyond that. If you have multiple dogs at home, separate the sick dog as much as possible. Shared water bowls, toys, and close face-to-face contact are the main transmission routes.
Signs the Infection Is Getting Worse
The vast majority of kennel cough cases resolve without drama, but a small percentage progress to pneumonia. This is the main complication vets watch for, and it’s the reason antibiotics get prescribed for higher-risk dogs in the first place.
Watch for these warning signs during recovery:
- Labored or rapid breathing at rest, not just after coughing fits
- Loss of appetite or lethargy that worsens rather than improves over the first few days
- Thick nasal discharge that turns green or yellow
- Fever, which you can check with a rectal thermometer (normal for dogs is 101 to 102.5°F)
- No improvement after a full week on antibiotics
Pneumonia requires more aggressive treatment and a longer recovery. If you notice any of these signs, contact your vet rather than waiting to see if the current course of antibiotics catches up. Early intervention makes a significant difference in outcome.