Upper Respiratory Infections in Dogs: Causes, Signs, and Treatment

An upper respiratory infection in dogs is a contagious illness that affects the nose, throat, and upper airways. It is one of the most common reasons dogs visit the veterinarian, and it can be caused by bacteria, viruses, or fungi that spread quickly in places where dogs spend time together.

These infections can range from mild and self-limiting to serious, especially in puppies, senior dogs, and dogs with underlying health conditions. This guide breaks down what causes upper respiratory infections in dogs, how to recognize them, and what treatment involves, so you know exactly when to act and what to expect.

What Is an Upper Respiratory Infection in Dogs?

An upper respiratory infection (URI) in dogs is an infection of the nose, throat, sinuses, and upper airway. It is sometimes called kennel cough, which is a colloquial term and is often used broadly referring to respiratory infections when caused by specific pathogens. URIs spread through direct contact with infected dogs, shared water bowls, and contaminated surfaces. They are especially common in kennels, shelters, grooming facilities, and dog parks.

What Causes Upper Respiratory Infections in Dogs?

Upper respiratory infections in dogs are caused by bacterial, viral, or fungal pathogens, and in many cases, more than one is involved at the same time.

Bacterial Causes

Bordetella bronchiseptica is the most well-known bacterial cause and the primary agent behind kennel cough. Mycoplasma species are also commonly involved and can complicate recovery when present alongside a viral infection.

Viral Causes

Several viruses contribute to canine upper respiratory infections, including canine parainfluenza virus, canine adenovirus type 2, canine influenza virus, and canine distemper virus. Vaccination significantly reduces the risk of several of these viral infections.

Fungal Causes

Fungi such as Aspergillus can infect the nasal passages and sinuses. Fungal URIs are less common but tend to be more persistent and require a different diagnostic and treatment approach.

What Are the Signs of an Upper Respiratory Infection in Dogs?

The most common signs of an upper respiratory infection in dogs include coughing, sneezing, nasal discharge, and eye discharge. Symptoms typically develop one to three days after exposure and can range from mild to severe.

Watch for these signs:

• Persistent coughing that sounds honking, hacking, or wet
• Sneezing, with or without nasal discharge
• Runny nose with clear, yellow, or green mucus
• Eye discharge or conjunctivitis
• Lethargy or reduced energy
• Loss of appetite or difficulty swallowing
• Mild fever

Seek immediate veterinary care if your dog shows labored breathing, blue-tinged gums, or extreme lethargy. These signs may indicate that the infection has spread to the lower respiratory tract and developed into pneumonia.

How Do Veterinarians Diagnose a Dog Upper Respiratory Infection?

Veterinarians diagnose upper respiratory infections in dogs through a physical examination combined with a review of your dog’s history, recent exposure to other dogs, and vaccination records.

Depending on what the exam reveals, your veterinarian at North Royalton Animal Hospital may recommend:

• Nasal or throat swabs to identify the specific pathogen
• Blood work to check for signs of infection or inflammation
• Chest X-rays if pneumonia or lower respiratory involvement is suspected
• Fungal cultures if a fungal cause is being considered

Accurate diagnosis matters because the treatment for a bacterial URI differs significantly from antifungal therapy or supportive care for a viral infection.

How Are Upper Respiratory Infections in Dogs Treated?

Treatment for a dog upper respiratory infection depends on the cause, the severity of symptoms, and your dog’s overall health. There is no single treatment approach that works for every case, which is why a veterinary examination is essential.

Bacterial Infections

Bacterial upper respiratory infections in dogs are typically treated with antibiotics. Your veterinarian will select the appropriate antibiotic based on the suspected or confirmed pathogen. Completing the full course of medication is critical to prevent antibiotic resistance and ensure the infection fully resolves.

Viral Infections

Most viral URIs do not have a targeted treatment. Supportive care including rest, hydration, and medications to manage symptoms like coughing — forms the foundation of recovery. Secondary bacterial infections sometimes develop on top of viral infections and may require antibiotic treatment as well.

Fungal Infections

Fungal upper respiratory infections are treated with antifungal medications, which are often administered over a longer course. Your veterinarian will monitor your dog’s response and adjust the plan as needed.

Can You Prevent Upper Respiratory Infections in Dogs?

Yes, staying current on vaccinations is the most effective way to reduce your dog’s risk of upper respiratory infections. Vaccines for Bordetella, parainfluenza, and canine distemper target some of the most common pathogens responsible for canine URIs.

Additional prevention strategies include:

• Avoiding contact with sick dogs and high-risk environments during outbreaks
• Disinfecting shared items like water bowls and toys regularly
• Scheduling routine wellness exams to catch early signs of illness

Dogs that are frequently boarded, groomed, or brought to dog parks benefit most from staying up to date on vaccines. Talk to the team at North Royalton Animal Hospital about which vaccines are right for your dog’s lifestyle.

When Should You Take Your Dog to the Vet for a Respiratory Infection?

Contact a veterinarian any time your dog shows signs of an upper respiratory infection, especially if symptoms have lasted more than a few days without improvement. Early treatment leads to faster recovery and reduces the risk of complications.

Schedule an appointment if:

• Nasal discharge becomes thick or changes color to yellow or green
• Your dog stops eating or shows signs of significant lethargy
• Coughing worsens or becomes productive
• Breathing appears labored or your dog seems distressed

North Royalton Animal Hospital serves dogs and their families throughout North Royalton, OH. If you are concerned about your dog’s respiratory health, call us at (440) 237-7691 or request an appointment for a thorough evaluation and a treatment plan designed specifically for your pet.