Respiratory Illnesses In Dogs
Respiratory issues are not only experienced by humans—dogs can also experience a range of breathing problems and respiratory illnesses. These respiratory problems can be troubling to dog owners, so it is important to be knowledgeable and understand how to spot symptoms of respiratory illness, how to treat it or manage it, and how to prevent it.
The Difference Between The Upper Respiratory Tract & Lower Respiratory Tract
The main role of the respiratory system is to deliver oxygen into the bloodstream and throughout the body and remove carbon dioxide from the blood. The upper respiratory tract includes the nose, nasal passages, sinuses, pharynx, and larynx and acts as a passageway for air to reach the lungs.
The lower respiratory tract includes the trachea, bronchi, bronchioles, and the alveoli in the lungs, which facilitate an exchange of oxygen and carbon dioxide in the lungs. When this exchange fails or becomes inefficient due to a disease or respiratory infection, a dog can become seriously ill.1
Common Dog Respiratory Illnesses & Infections
There are a number of different respiratory illnesses and conditions that can affect dogs, including:
- Kennel Cough
- Tracheal Collapse
- Upper Respiratory Infections (like dog flu)
- Chronic Bronchitis
- Eosinophilic Bronchopneumopathy
- Lung Diseases, most frequently lung tumours2
Kennel cough, also referred to as Canine Infectious Tracheobronchitis, is a highly contagious upper respiratory illness caused by several strains of bacteria and viruses. Dogs can spread it to one another in a variety of ways including airborne droplets, direct contact, or through contaminated surfaces (including water/food bowls).
Even though it is highly contagious, it is also highly treatable in most dogs. However, it can be more severe in puppies younger than six months of age and immunocompromised dogs.3
Symptoms of Kennel Cough
- Strong, persistent cough
- Runny nose
- Loss of appetite
- Low grade fever
Diagnosis and Treatment of Kennel Cough
It can be challenging to diagnose kennel cough because sometimes dogs do not show symptoms.
Other conditions may present similar symptoms, such as a collapsing trachea, bronchitis, asthma, heart disease, and pneumonia. The latter can develop due to a weakened immune system which is why it’s vital to have a veterinarian assess your dog to identify the root of the symptoms.
If the case of a dry, hacking cough doesn’t appear to be a more serious condition, then in many cases the cough is harmless and will disappear in a couple of weeks. If kennel cough has been identified, rest and/or cough medication will be prescribed by your veterinarian. Inhaled antibiotics or bronchodilators may be prescribed to help control your dog’s cough and clear up the infection.
Prevention of Kennel Cough
Kennel cough is often transmitted through bacteria. You can have your dog vaccinated for the bordetella bacterium, which is the most common factor in causing it. If you know that your dog is going to be routinely exposed to large groups of other dogs such as in boarding facilities, day care, canine sports, and training classes it is vital to get your pup vaccinated.4
Canine Distemper Virus
Canine Distemper Virus (also known as Footpad or Hard Pad Disease) is a viral contagious and serious disease that affects a range of animal families. It is a virus that affects a dog’s upper and lower respiratory system as well as the nervous and gastrointestinal systems. It can also cause the pads of dogs’ feet to thicken or harden, hence the alternative names for the virus.
Dogs at any age are at risk of contracting Canine Distemper Virus, but puppies younger than four months old and dogs that have not been vaccinated are at the highest risk of the disease.
It is best identified early, especially if dogs are kept in close proximity to one another as it can spread quickly through airborne exposure (through sneezing or coughing).
Symptoms of Canine Distemper Virus
- Watery to pus-like discharge from the eyes
- Reduced appetite
- Circling behaviour
- Muscle twitches
- Partial or complete paralysis5
Diagnosis and Treatment of Canine Distemper Virus
It is vital to diagnose and treat distemper as soon as possible because it is often fatal. Dogs that survive can suffer from permanent, irreparable nervous system damage.
Unfortunately, treatment options are limited but vaccinations are available from your veterinarian. Treatment options include supportive care and prevention of secondary infections.
Prevention of Canine Distemper Virus
The best line of defence for preventing distemper in your dog is to have a series of vaccinations given to your dog while they are still a puppy. This will help build their immunity while their immune system is developing. Always make sure to keep up to date with all of your dog’s vaccinations and avoid gaps in their immunization schedule.
Keep shared food, water bowls, and equipment clean and sterile as this disease can be transmitted through contact with contaminated surfaces. Try to limit the interaction your dog has with wildlife populations; the virus also occurs in foxes, wolves, coyotes, raccoons, skunks, mink, and ferrets and can be transmitted through this type of interaction.
Canine Chronic Bronchitis
Canine chronic bronchitis is a long-term condition that causes inflammation in the respiratory system and over time permanent lung damage. Chronic obstructive pulmonary disease (COPD) can occur in all breeds of dogs, but may be more common in small-breed and toy-breed dogs.
Unfortunately, bronchitis in dogs is irreversible, progresses slowly, and can’t be cured. However, there are treatments that can help manage the disease and slow progression.
Symptoms of Canine Chronic Bronchitis
- Wheezing or other abnormal lung sounds
- Difficulty breathing
- Vomiting or retching
- Loss of consciousness
Dogs with mild or moderate bronchitis may not regularly show visible symptoms even though the disease may be progressing and causing worsening lung damage.
Diagnosis and Treatment of Canine Chronic Bronchitis
If you suspect that your dog is suffering from chronic bronchitis, take them to the vet for a review of their medical history and a physical examination. The vet may perform other diagnostic tests such as X-rays, bronchoscopy, and a tracheal wash to determine if your pet is suffering from chronic bronchitis.
Treatments for dogs with chronic bronchitis are usually administered at home but if your pet is experiencing severe respiratory distress, hospitalization for oxygen therapy and/or intravenous medication may be necessary.
Helpful medications include corticosteroids to reduce underlying inflammations and keep symptoms at bay. Bronchodilators (or “rescue medications”) may be recommended to help open the airways while your dog is in distress but the evidence is not clear on their effectiveness in dogs.
The AeroDawg* aerosol chamber allows dogs to easily inhale corticosteroids and bronchodilators. With its specially designed chamber, the AeroDawg* chamber contains the medication, giving your dog time to breathe in the dose and directly targeting the lower airways.
Prevention of Canine Chronic Bronchitis
Determining prevention methods for bronchitis can be challenging because no exact underlying cause has been determined. It is advised to limit your dog’s exposure to inhaled irritants to help keep symptoms under control. These irritants include:
- Air pollution
- Allergens (such as grass and dust)
Pneumonia is an infection of the lungs caused by inflammation of the alveoli in the lungs. These sacs fill with fluid or pus, making it hard to breathe.
The causes stem from a range of triggers including allergens, lungworms, bacteria, viruses, aspirated food, fluids, or foreign bodies.
Symptoms of Pneumonia
- High fever
- Difficulty breathing
- Decreased exercise tolerance (tire easily)
- Nasal discharge
- Loud breathing
- Rapid breathing
- Weight loss
- Lack of appetite
Diagnosis and Treatment of Pneumonia
Your veterinarian will assess your dog’s symptoms and rule out other non-infectious respiratory diseases such as bronchitis, heart disease causing pulmonary edema, and lung cancer. They will do a thorough physical examination and recommend a series of diagnostic tests before determining a diagnosis of pneumonia.
To treat pneumonia, your veterinarian will likely prescribe a round of antibiotics and, in some cases, fluid therapy, chest percussion, oxygen therapy and/or intravenous fluids.
Some dogs that are healthy and stable enough are treated as outpatients are prescribed bronchodilators and/or expectorants (mucoactive agents which aid in the clearance of mucus from the upper and lower airways). Depending on the severity of the condition and type of infection, your dog may be required to continue this treatment for a prolonged period of time.
Prevention of Pneumonia
The first course of action in preventing your dog from contracting bacterial or viral pneumonia is to vaccinate them for the diseases that can cause it.6 If a dog is presenting signs and symptoms of pneumonia they should be isolated and kept away from other dogs to help curb the spread.
Environmental factors can play a role in a dog's respiratory health, so it’s important to keep inhaled irritants to a minimum. This includes keeping the air in the house clean by using air purifiers, avoiding aerosol sprays, and refraining from smoking around your dog.
Canine eosinophilic bronchopneumopathy (EBP) is a respiratory issue that tends to be overlooked as it is relatively uncommon. It is characterized by a dog’s harsh unrelenting cough, similar to a “smoker’s cough”, and dyspnea (shortness of breath). It stands apart from chronic bronchitis as it occurs mostly in young dogs (4-6 years old, females affected more than males), presents eosinophils7 (specialized immune system white blood cells) in airway samples, and there may be traces of nasal discharge. EBP has been seen in Labrador Retrievers, Alaskan Malamutes, German Shepherds, fox and Jack Russell Terriers, Dachshunds, Belgian Shepherds, Brittanys and Siberian Huskies. However, all breeds can be affected with this condition.
Symptoms of Eosinophilic Bronchopneumopathy
These are some symptoms to be aware of if you suspect that your dog may be experiencing EPB:
- Cough (present in 95%-100% of cases8), persistent and harsh which can be followed by gagging or retching.
- Dyspnea (shortness of breath).
- Exercise intolerance
- Nasal discharge (mucus and pus-like).
Lethargy and anorexia are less common but may be displayed if pneumonia is present.
Diagnosis and Treatment of Eosinophilic Bronchopneumopathy
A veterinarian may use one or more of the following diagnostic methods to determine if your dog has EPB.
- Physical examination and laboratory evaluation.
- Imaging (to rule out other conditions).
- Cytology (sampling of airway cells).
- Bronchial pinch biopsies (when cytology is uncertain).
The main focus in treatment of EPB is to lessen the suffering and severity of the symptoms. A final resolution of this clinical disease may not happen and treatment may be required on an ongoing basis. This may include the use of antimicrobial drugs and/or anti-inflammatory corticosteroid (steroid hormones) therapy. It is important to note that anti-inflammatory corticosteroid therapy should not be prescribed until any bacterial infections are eliminated.
Prevention of Eosinophilic Bronchopneumopathy
There is no sure cause of EPB but the condition is suspected to have allergic roots. So prevention methods surround keeping potential allergenic triggers to a minimum and ideally eliminated. Aerosolized deodorizers and perfumes, particulate matter in bedding (cedar chips, straw, and sawdust), cigarette smoke, and dusty environments should be avoided.
Lung problems and diseases in dogs, including lung tumours, can also impact respiratory health. Lung tumours can develop in dogs in two ways:
- Primary lung tumours which originate in the lungs and tend to be less common.
- More commonly, metastatic lung tumours that originate in another part of the body and then spread to the lungs.
Primary lung cancers have been diagnosed more frequently over the last 20 years, which can be attributed to a few factors including increased average life span, improved detection and awareness, and possibly increased exposure to cancer-causing environmental agents.9
Symptoms of Lung Tumours
Symptoms of primary lung tumours depend on the location of the tumor, rate of tumor growth, and the presence of previous or current lung disease. The most common signs of a primary lung tumor in dogs include:
- Weight loss
- Labored breathing
- Poor appetite
- Reduced exercise tolerance (tire easily)
- Rapid breathing
- Vomiting or regurgitation
While these signs are important to be aware of, 25% of dogs show no signs related to the presence of a tumor, therefore going undiagnosed for prolonged periods.10
The signs of a metastatic lung tumor are similar to those of a primary lung tumor but the one main difference is there is less coughing. The severity of the symptoms also depend on the location of the tumor and whether the lesions are single or multiple.
Diagnosis and Treatment of Lung Tumours
The diagnostic protocols are similar for both primary lung tumours and metastatic lung tumours. This can include chest x-rays, ultrasound-guided aspiration or biopsy, abdominal ultrasound, CT scans (to evaluate for secondary lung metastases and/or inspection for surgical removal) and blood work to determine overall health.
Often, primary lung tumours are discovered when x-rays are done for other reasons and their results show signs of an undetected tumor. To make a conclusive diagnosis of lung cancer, a biopsy is required.
There are two main routes to take in treatment of a primary lung tumor and a metastatic lung tumor. The first is surgery, but there must be no signs of metastatic lesions on other lung lobes otherwise there is potential for recurrence. Working in tandem with surgery chemotherapy could also be needed depending on the grade, size and, presence of the tumor.
For high grade tumours, large tumours, or tumours that indicate lymphatic or vascular invasion, chemotherapy is recommended. It is important to note that chemotherapy prescribed on its own, without surgical removal of the mass, will not result in significant size reduction or improved survival time.
Prevention of Lung Tumours
Similar to humans, there is no infallible cure for cancer in dogs,but we do know that there are certain factors that can be avoided to help stop the development of malignant tumours. Breathing in secondhand smoke is as dangerous for dogs as it is for humans and can increase the risk of both types of lung tumours. The best prevention method available is for dog owners to stop smoking or smoke outside.
Help Manage Your Dog’s Respiratory Health
It can be extremely troubling for an owner to find out your dog has been diagnosed with a respiratory illness. However, understanding the various respiratory illnesses, symptoms to be aware of, diagnosis and treatment options, and prevention methods can help put you in the best position to prioritize and manage your dog’s respiratory health.