Bronchitis in Dogs: Causes, Symptoms and Treatment

Bronchitis in dogs is a common illness that affects the upper airways and causes coughing. If the cough lasts more than two months, it's generally referred to as chronic bronchitis.

To understand the disease, it's first important to know about the basic anatomy that's involved. Air enters the body through the mouth or nose and flows through the trachea, also known as the windpipe. The air then travels into smaller air passages called bronchi before reaching the smaller bronchioles and, finally, the tiny alveoli, where oxygen enters the bloodstream.

What Is Bronchitis?

Bronchitis is a disease characterized by inflammation in the bronchi and bronchioles — the parts of the lungs through which oxygen-rich air travels. Inflammation in these airways leads to mucus production, coughing and irritation. This stimulates the production of more mucus and leads to a cycle of constant inflammation.

Infectious tracheobronchitis is a related disorder that involves the trachea, bronchi and bronchioles. It's more commonly associated with acute disorders similar to kennel cough. Chronic bronchitis, by contrast, typically doesn't involve the trachea. It's important to recognize this difference as the disorders may look similar but have different causes and treatments. Your veterinarian will be the best resource for distinguishing between and diagnosing both.

Symptoms of Bronchitis in Dogs

Dogs with bronchitis may have a cough that's wet, dry or honking. In some cases, pet parents might confuse the cough for gagging or vomiting, so it's helpful to take a short video of the behavior for your veterinarian's benefit.

While your dog's coughing can seem minor, it might indicate a problem. At the first sign of a persistent cough, bring your dog to the vet. This is particularly important if the cough's characteristics change — if it gets more frequent, louder or softer, wetter or dryer.

Causes of Bronchitis in Dogs

Bronchitis in dogs can be caused by anything that irritates the airways or otherwise stimulates an inflammatory reaction. The key is to distinguish it from other causes of coughing, such as:

• Bacterial or viral tracheobronchitis, also known as kennel cough
• Pneumonia
• Tracheal collapse
• Fungal lung infections
• Parasites, like lungworms and heartworms
• Cancer
• Heart failure
• Foreign bodies

In many cases, these disorders can exacerbate chronic bronchitis. The true cause of the disorder, however, is the inflammatory cycle that's initiated and perpetuated by the reactivity of the dog's respiratory passages.

Note that asthma is quite distinct from chronic bronchitis and isn't common in dogs. Your veterinarian can help explain each of these problems as it pertains to your dog's specific case.

Diagnosis of Chronic Bronchitis in Dogs

Vets diagnose chronic bronchitis based on a variety of factors, including the dog's health history and a physical exam. To help make a diagnosis and rule out other causes of coughing, they use the following tools:

• Chest X-rays: A distinct pattern is visible in many patients with chronic bronchitis.
• Bronchoscopy: Bronchitis has a characteristic appearance when seen through a small lens. A bronchoscopy visualizes the airways directly. This procedure can be expensive and difficult to perform in many patients, especially in small pets. It will require your dog to be put under general anesthesia. This procedure frequently needs to be performed at a specialty hospital, too.
• Bronchoalveolar lavage: Also called bronchial washing, this involves evaluating samples of the mucus and cells by microscopy and culture and sensitivity testing. This can help achieve a definitive diagnosis. For this procedure your dog will be premedicated as well as put under general anesthesia.
• Bloodwork: While it won't lead to a definitive diagnosis, bloodwork can help eliminate other causes and complications.

Treatment Options

Most dogs with bronchitis can be successfully treated. The ultimate goal of treatment is to curb the cycle of mucus production and inflammation. To treat your dog, your vet will likely recommend one or more of the following:

• Oral medicine, including anti-inflammatory corticosteroids like prednisone, airway dilators and mucus-busting drugs designed to loosen or thin secretions
• Cough suppressants
• Antibiotics (if secondary infections are a factor)
• Nebulization (delivery of medicine through a mist to be inhaled into the lungs) and coupage (a procedure performed by a veterinarian where they strike the chest of the dog with cupped hands) to moisten the airways and release mucus

Versions of these medications may also be available delivered through an inhaler. These may reduce side effects by delivering drugs directly to the airways.

In addition, weight loss is often deemed crucial for bronchitis patients. The added pressure on airways as a result of excess weight can worsen the vicious cycle of inflammation and mucus accumulation.

Prevention

Though bronchitis most commonly affects small middle-aged to senior dogs, all dogs are potentially at risk. While doctors believe that a dog's level of airway reactivity is hereditary, environmental factors also play a role. Keeping your dog at a healthy weight also plays a crucial role in helping prevent bronchitis. Less pressure on their airways can help them better fight off the condition.

Cigarette smoke, diffused essential oils, household cleaners, paint fumes and construction dust are all considered potential irritants. It's wise to keep your pet away from these, especially if they've had chronic bronchitis in the past.

Chronic bronchitis also has a seasonal factor. Dogs living in areas where dust pollen or smoke are common during certain times of the year may be at a higher risk of the condition. Sudden weather changes may also worsen signs. Keeping dogs indoors during times of the year found to exacerbate signs can be helpful.