Kennel cough — more accurately called canine infectious respiratory disease complex (CIRDC) — is a highly contagious group of respiratory infections in dogs. It is characterized by a sudden-onset, harsh, honking cough that can persist for one to three weeks. While most cases are self-limiting in otherwise healthy adult dogs, kennel cough can progress to serious pneumonia in puppies, elderly dogs, and immunocompromised animals. Understanding the causes, recognizing symptoms, and knowing when to seek veterinary care are important for any dog owner.
Overview
CIRDC is not caused by a single organism but rather by a combination of viral and bacterial pathogens that damage the respiratory epithelium:
Primary bacterial agents:
- Bordetella bronchiseptica — The most commonly implicated bacterium; can cause disease alone or in combination with viruses
Common viral agents:
- Canine parainfluenza virus (CPIV)
- Canine adenovirus type 2 (CAV-2)
- Canine respiratory coronavirus (not the same as canine enteric coronavirus)
- Canine influenza virus (H3N2 and H3N8 strains)
- Canine pneumovirus
- Canine herpesvirus
Other bacterial agents:
- Mycoplasma cynos
- Streptococcus equi subsp. zooepidemicus (can cause severe hemorrhagic pneumonia)
Infection typically occurs through aerosolized respiratory droplets, direct nose-to-nose contact, or contaminated surfaces (fomites). Dogs in close quarters — boarding facilities, shelters, grooming salons, dog parks, and training classes — are at highest risk. The incubation period is typically 2 to 14 days depending on the pathogen.
Symptoms
The hallmark of kennel cough is a sudden-onset, dry, hacking cough that may sound like honking or gagging. Owners frequently describe it as “something stuck in the throat.” Symptoms range from mild to severe:
Mild cases:
- Harsh, dry cough (often triggered by excitement, pulling on a leash, or gentle tracheal pressure)
- Occasional retching or gagging after coughing fits
- Otherwise normal appetite, energy, and behavior
- Mild clear nasal discharge
More severe cases (seek veterinary care promptly):
- Persistent cough that worsens or does not improve after 5 to 7 days
- Thick or colored (yellow/green) nasal discharge
- Lethargy or decreased appetite
- Fever
- Productive (wet) cough suggesting lower respiratory involvement
- Rapid or labored breathing
- Puppies or elderly dogs showing any respiratory signs
Diagnosis
Diagnosis is often based on clinical signs and history (exposure to other dogs in a group setting) combined with physical examination:
- Physical examination — Tracheal sensitivity (cough easily elicited by gentle pressure on the trachea) is a classic finding. Lung auscultation may be normal or may reveal crackles or wheezes in more severe cases.
- Chest radiographs — Not always necessary for mild cases but recommended when pneumonia is suspected (fever, lethargy, productive cough, labored breathing).
- PCR respiratory panels — Nasopharyngeal or oropharyngeal swabs can identify specific pathogens (Bordetella, canine influenza, Mycoplasma, etc.). Most useful for outbreak investigation or when canine influenza is suspected.
- Culture and sensitivity — May be performed on transtracheal wash or bronchoalveolar lavage samples in severe or non-responsive cases.
Treatment & Medications
Treatment depends on severity:
Mild Cases (Uncomplicated)
Many mild cases resolve on their own within 1 to 3 weeks with supportive care:
- Rest and restricted exercise to reduce coughing
- Using a harness instead of a collar to avoid tracheal pressure
- Humidified air (running a shower to create steam or using a cool-mist humidifier)
- Isolating the affected dog from other dogs for at least 2 weeks to prevent spread
- Monitoring for progression to more severe signs
Your veterinarian may prescribe a cough suppressant for comfort if the cough is severe enough to disrupt sleep or eating:
| Medication | Purpose | Notes |
|---|---|---|
| Hydrocodone | Opioid cough suppressant | Prescribed for severe, non-productive coughing that affects quality of life. Controlled substance. |
| Butorphanol | Opioid cough suppressant | Alternative cough suppressant. |
| Dextromethorphan | Non-opioid cough suppressant (OTC) | Sometimes used for mild cases; effectiveness in dogs is debated. Only use under veterinary guidance. |
Cough suppressants should NOT be used if pneumonia is suspected, as the cough reflex helps clear infected material from the airways.
Moderate to Severe Cases
When bacterial infection is more significant or pneumonia is developing:
| Medication | Purpose | Notes |
|---|---|---|
| Doxycycline | Antibiotic of choice for CIRDC | Effective against Bordetella and Mycoplasma. Typically a 10 to 14 day course. Give with food to reduce esophageal irritation. |
| Amoxicillin-Clavulanate | Broad-spectrum antibiotic | Alternative when doxycycline is not tolerated. |
| Enrofloxacin | Fluoroquinolone antibiotic | Reserved for documented resistant infections or severe pneumonia. |
| Maropitant (Cerenia) | Anti-nausea; may have mild antitussive effects | Sometimes used for nausea or mild cough relief. |
| Nebulization and coupage | Supportive therapy for pneumonia | Aerosolized saline (with or without antibiotics) followed by chest percussion helps clear airway secretions. |
Severe pneumonia may require hospitalization with IV fluids, injectable antibiotics, oxygen therapy, and intensive monitoring.
Prevention
Vaccination is the primary preventive strategy:
- Bordetella vaccine — Available as intranasal, oral, or injectable formulations. Often required by boarding facilities and grooming salons. Intranasal and oral vaccines may provide faster local immunity (within 48 to 72 hours).
- Canine parainfluenza and adenovirus-2 — Included in core combination vaccines (DHPP/DA2PP).
- Canine influenza vaccine (H3N2/H3N8) — A non-core vaccine recommended for dogs at increased risk (frequent boarding, dog shows, areas with known outbreaks).
No vaccine provides 100% protection against CIRDC because the disease involves multiple pathogens, and new strains can emerge. Vaccination reduces the severity and duration of illness even when infection occurs.
Prognosis
- Uncomplicated kennel cough in healthy adult dogs — Excellent prognosis. Most cases resolve within 1 to 3 weeks.
- Complicated cases with secondary bacterial pneumonia — Generally good prognosis with appropriate antibiotic therapy, though hospitalization may be required.
- Puppies, elderly dogs, or immunocompromised dogs — More guarded prognosis, as these groups are more susceptible to severe pneumonia.
- Canine influenza — Can cause more severe illness than typical kennel cough; a small percentage of dogs (particularly with H3N2) may develop severe hemorrhagic pneumonia.
Frequently Asked Questions
Is kennel cough contagious to humans? Bordetella bronchiseptica can rarely infect immunocompromised humans, but this is extremely uncommon. Canine influenza is not known to infect humans. Standard hygiene practices (hand washing) are sufficient.
My dog is vaccinated for Bordetella but still got kennel cough. Why? The Bordetella vaccine protects against one of many pathogens that cause CIRDC. Your dog may have been infected by a different virus or bacterial agent. Vaccination still provides benefit by reducing disease severity.
How long should I keep my coughing dog away from other dogs? At least 2 weeks after coughing has completely resolved. Some pathogens (particularly Bordetella) can be shed for several weeks even after clinical signs have resolved.
Can my dog get kennel cough more than once? Yes. Because multiple different pathogens cause CIRDC, and immunity to some agents (particularly Bordetella) may wane over time, dogs can be infected multiple times. This is why annual or more frequent Bordetella vaccination is recommended for at-risk dogs.
Should I be concerned about the cough outbreaks reported in the news? Periodic outbreaks of severe respiratory illness in dogs receive media attention. If you are concerned, consult your veterinarian about your dog’s vaccination status and any regional outbreaks. Keeping vaccines current, avoiding close contact with visibly ill dogs, and seeking prompt veterinary care for persistent or worsening respiratory signs are the best strategies.