There may be many reasons why dogs are susceptible to pneumonia, including infection with viruses, bacteria, or fungi, or a weakened immune system due to other health problems. Specifically, dogs can be infected with various types of pneumonia viruses, including influenza, adenovirus, and canine distemper virus. These viruses can be spread through the respiratory tract or through contact infection.
Dogs may also be infected with pneumonia bacteria such as Mycobacterium tuberculosis, Pseudomonas aeruginosa, and Streptococcus pneumoniae. These bacteria can be spread through the respiratory tract or through infection through food, water or other items. Dogs can also develop fungal infections such as mold and yeast. These fungi often colonize a dog's respiratory tract or lungs and can cause pneumonia.
