Most dogs with kennel cough recover on their own within three weeks without any medication. When symptoms are more than mild, veterinarians typically prescribe doxycycline as the first-choice antibiotic, often alongside a cough suppressant to help the dog rest. The specific combination depends on how sick your dog is, whether a bacterial infection is suspected, and whether there are any complicating health conditions.
When Medication Is Actually Needed
Kennel cough, formally called canine infectious respiratory disease complex, usually starts as a dry, honking cough that sounds worse than it is. In straightforward cases, the infection clears up on its own in one to three weeks, sometimes stretching to six. Vets generally reserve prescriptions for dogs showing signs that a bacterial infection has taken hold: thick, colored nasal discharge, fever, lethargy, or loss of appetite. A dog that’s coughing but otherwise eating, drinking, and acting normally may just need rest and monitoring at home.
Doxycycline: The First-Line Antibiotic
International veterinary guidelines from the International Society for Companion Animal Infectious Diseases recommend doxycycline as the go-to antibiotic for kennel cough. It’s prescribed for 7 to 10 days and works against both Bordetella bronchiseptica, the most common bacterial culprit, and Mycoplasma, another organism frequently involved. Dogs tolerate it well overall.
The most common side effects are digestive: vomiting, diarrhea, and reduced appetite. Giving doxycycline with food helps. One important caution is that the pill should never be given dry. If it gets stuck in the esophagus, it can cause ulceration and scarring that makes swallowing painful. Always follow it with water or a small amount of food. Less common but more serious reactions include elevated liver enzymes, increased sun sensitivity on hairless skin like the nose and ears, and in rare cases, liver failure or behavioral changes.
If Doxycycline Doesn’t Work
When a dog doesn’t improve on doxycycline or can’t tolerate it, amoxicillin-clavulanate is the usual backup. It covers a broad range of bacteria including Pasteurella, Streptococcus, and most Bordetella strains. The limitation is that some Bordetella isolates and all Mycoplasma species are resistant to it, so it’s considered a second-line option rather than equal to doxycycline.
Cough Suppressants for Comfort
Antibiotics address the infection, but they don’t stop the cough itself. When the coughing is persistent enough to disrupt sleep, cause gagging, or clearly distress the dog, vets often add a prescription cough suppressant. The two most commonly used are hydrocodone and butorphanol, both opioid-based medications that dampen the cough reflex.
These come with real tradeoffs. Opioid cough suppressants can cause sedation, constipation, and respiratory depression. Their effectiveness also varies from dog to dog. They’re especially problematic in cats, where excitement and muscle spasms are additional risks. More importantly, cough suppressants are contraindicated if the infection has progressed to pneumonia. Coughing is actually the body’s way of clearing mucus and bacteria from the airways, so suppressing it during pneumonia traps infectious material in the lungs and makes things worse. Your vet will listen to your dog’s chest before prescribing one.
Anti-Inflammatories and Bronchodilators
For dogs with significant airway inflammation or wheezing, vets sometimes prescribe a short course of oral steroids like prednisone to reduce swelling in the airways. This is typically a 5-day course for moderately affected dogs, with longer or repeated dosing reserved for more severe cases. Steroids carry their own risks: they can mask underlying disease, cause panting and weight gain (both of which stress the respiratory system), and should be used cautiously in dogs with diabetes, Cushing’s disease, heart failure, high blood pressure, kidney disease, or gastrointestinal ulcers.
In cases where the airways are constricted and the dog is struggling to breathe, a bronchodilator like albuterol (delivered through an inhaler or nebulizer) can relax the smooth muscle around the airways and open them up quickly. These provide symptom relief but don’t treat the underlying inflammation or infection, so they’re used alongside other medications rather than alone.
What Recovery Looks Like
With antibiotics, most dogs start improving within a few days, though the cough itself often lingers. The full course of 7 to 10 days of antibiotics should be completed even if your dog seems better early. Without treatment, recovery takes about three weeks on average but can drag on for up to six weeks. Medication shortens the illness and reduces the chance of complications like pneumonia, but it doesn’t eliminate the cough overnight.
During recovery, keeping your dog in a humid environment can help soothe irritated airways. Using a harness instead of a collar avoids putting pressure on the trachea, which tends to trigger coughing fits. Your dog remains contagious to other dogs for much of the illness, so isolation from other pets and skipping the dog park are standard until the cough resolves.
Prevention Through Vaccination
Vaccines against Bordetella and canine parainfluenza virus are widely available as intranasal sprays, oral drops, or injections. In clinical studies, oral vaccination reduced the rate of illness from 74% in unvaccinated dogs to just 9% in vaccinated dogs after direct exposure. Vaccinated dogs also shed the virus for a median of one day compared to six days in unvaccinated dogs, and coughing from Bordetella infection dropped by 65%. Seroconversion rates were high: 91% of dogs developed neutralizing antibodies against parainfluenza, and 100% developed strong antibody responses against Bordetella after a single oral dose.
No vaccine provides complete protection, and kennel cough can be caused by a mix of viruses and bacteria that no single vaccine covers entirely. But vaccination significantly reduces the severity and duration of illness if your dog is exposed, and most boarding facilities, groomers, and dog daycares require it.