Respiratory Illness in Dogs: Recognition, Prevention, and Planning

Infectious respiratory illnesses in dogs can pose a minor inconvenience, or a serious threat to long-term health and wellness. These diseases are induced by pathogens that target a dog’s lungs, airways, and mucous membranes.

Periodically, veterinary professionals and the media will alert pet owners that an uptick in respiratory illnesses has been reported in a particular area. It can take some time to identify what pathogen(s) are responsible for the epidemic. When this happens, it can be useful for dog lovers to understand the general nature of respiratory diseases and know the measures that they can take to keep their companions as healthy as possible.

Recognizing Respiratory Illness

Respiratory illnesses in dogs can range from mild to severe and typically involve the nasal passages, trachea, and lungs. Common symptoms include:

• Coughing
• Sneezing
• Nasal discharge
• Respiratory noises like wheezing or snoring
• Difficulty breathing
• Reduced appetite
• Lethargy
• Red eyes or ocular discharge

In addition to knowing the common clinical signs of respiratory infections, it is also important to remember that infected animals can sometimes spread respiratory pathogens before they become visibly ill.

Known Respiratory Pathogens in Dogs

Canine Infectious Respiratory Disease Complex (CIRDC)

Canine Infectious Respiratory Disease Complex is commonly referred to as kennel cough. It is a highly contagious respiratory disease characterized by a harsh, hacking, or goose-honking cough. It is caused by infections with one or more viral and bacterial pathogens, including canine parainfluenza virus, Bordetella bronchiseptica, and strep. Stressed pets, and those spending time in group settings with other dogs are more at risk for infection.

Canine Influenza

Canine influenza, or dog flu, is caused by a highly contagious virus. The disease emerged when influenza variants from horses and birds mutated to be able to infect dogs. Because dogs commonly travel with their owners, the disease has spread quickly. An infection with canine influenza can be asymptomatic or very mild, or very severe, resulting in pneumonia. This illness is also considered to be part of CIRDC.

Canine Distemper

Another notable respiratory illness in dogs is Canine Distemper. This disease is caused by a highly contagious paramyxovirus. It leads to fever and respiratory signs like coughing and nasal discharge. It may also cause gastrointestinal, neurological, and dermatological complications. Distemper affects not only wild and domestic dogs, but also raccoons, foxes, and skunks, and is particularly pathogenic for ferrets.

COVID-19 and Dogs

While COVID-19 primarily affects humans, there have been cases where dogs contracted the virus. Typically, infected dogs show mild respiratory symptoms, if any. Currently, the risk of dogs spreading COVID-19 to people and other dogs is considered low.

Modes of Transmission

Respiratory illnesses in dogs are primarily transmitted through:

• Inhalation of airborne particles from coughing or sneezing
• Direct contact with infected dogs
• Contact with contaminated surfaces or objects like bedding, toys, and food/water bowls

Understanding these transmission modes is crucial in controlling the spread of these diseases. Dogs that are stressed by concurrent illness or lifestyle factors may be more likely to contract and spread respiratory infections.

Risk Factors

Certain factors increase a dog's susceptibility to respiratory illnesses:

• Brachycephalic Conformation. Dogs with short noses and flat faces, like Pugs and Bulldogs, are more prone to respiratory issues. Mild respiratory infections are more likely to cause severe complications like pneumonia, respiratory distress, and death in these breeds.
• Stress. High-stress environments can weaken a dog's immune system. Dogs experiencing illness, lifestyle changes, or group housing such as stays in shelters, kennels, or hospitals are more vulnerable to severe illness.
• Concurrent Illnesses. Conditions like asthma, Chronic Obstructive Pulmonary Disease, and pulmonary fibrosis make the lungs more fragile. Dogs with these conditions, or other illnesses that impact immune function, are more likely to experience severe complications of infectious respiratory conditions. Additionally, pets undergoing immune-suppressing treatment for cancer, dermatological conditions, and others are more at risk.
• Lifestyle Factors. Frequent and prolonged contact with other dogs increases the chance of disease transmission. Kennels, daycares, dog shows, hospitals, shelters, and training facilities are prime areas for transmission to occur.

Prevention Strategies

Preventative measures are a powerful tool for reducing the risk and severity of respiratory diseases:

• Vaccination. Keep current on vaccinations against common pathogens like Canine Distemper, Bordetella, and Canine Influenza. This reduces the risk and/or severity of infectious respiratory diseases.
• Infection Control. Avoid contact with sick or unknown dogs. Maintain good hygiene by regularly washing water bowls, toys, and bedding.
• Lifestyle Measures. Reduce stress by keeping a regular routine and offering proper nutrition and regular exercise to boost overall health. Avoid high-traffic areas where your dog will interact with other dogs of unknown vaccination status. Be aware that many dog-friendly venues require vaccination for core illnesses only, leaving out requirements for non-core vaccination against pathogens like Canine Influenza and Bordetella.

Respiratory infections usually cause mild and transient illness in healthy young dogs. Young puppies, senior pets, and chronically ill animals are at greater risk for developing serious complications. Brachycephalic dogs like Frenchies, Pugs, and Bulldogs can develop more severe clinical signs and require more veterinary support for recovery.

Understanding the clinical signs, common paths of transmission, and available preventative measures can help you develop a plan to keep your pet safe and healthy when infection rates are high or when the cause of an outbreak is not yet identified. Stay on top of regular veterinary checkups and vaccines, and maintain good communication with your family veterinarian. These measures will ensure that you stay informed and prepared for local outbreaks.