Fungal Pneumonia in Dogs
Fungal pneumonia refers to a form of pneumonia in which the lungs become inflammed due to a deep fungal infection, known as a mycotic infection. The inflammation in this form of pneumonia may occur in the interstitial tissues (the spaces between the tissue cells); in the lymphatic vessels (the vessels within the body that transport white-blood-cell-rich lymph liquid); or in the peribronchial tissues of the lung (the tissues surrounding the bronchi -- the airways going from the windpipe to the lungs).
Both dogs and cats may develop fungal pneumonia, although this type of pneumonia occurs less commonly in cats. Some dogs are more susceptible to certain types of fungal disease; for example, German Shepherds appear to be more susceptible to infection from the Aspergillus fungus. Male dogs are affected two to four times as often as females.
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Symptoms and Types
Symptoms of fungal pneumonia may include a history of anorexia and corresponding weight loss, fever, discharge from the nose or eyes, coughing, difficulty breathing, lameness, and eye problems, possibly as severe as sudden blindness. A physical exam may also reveal depression, emaciation, and a crackling sound in the lungs while breathing.
There are a number of fungi that can cause mycotic (deep fungal) infections; some of these include Blastomyces, Histoplasma, and Aspergillus. Fungal pneumonia is geographically varying, as the different fungi responsible for mycotic infection are found in various areas of the United States. Blastomycosis, from the Blastomyces organism, for example, is found in the Southeast and Midwest, while Aspergillosis, from the Aspergillus organism, is widespread throughout the United States.
Contact with one of the fungi capable of causing mycotic infection may lead to fungal pneumonia. The exact method of contraction varies depending on the specific type of fungus. Blastomyces dermatitidis, for example, primarily enters the body by inhalation into the lungs, while the Cryptococcus neoformans fungal organism generally enters the body through the nasal cavity and then migrates into the eyes and/or central nervous system from this point of entry.
Environmental exposure to any of the fungi responsible for causing fungal pneumonia may lead to the development of this disease. Thus, exposure to soils rich in organic matter, bird droppings, or fecal matter may increase the odds of contracting it.
The only way to definitively diagnose fungal pneumonia is to identify the potential organism through the analysis of a skin nodule sample, or biopsy of a lymph node. Further diagnostic procedures may include urine analysis, thoracic radiographs of the chest and lungs, and abdominal ultrasounds.
If fungal pneumonia is not the cause of the dog’s symptoms, other forms of pneumonia, such as parasitic or bacterial-induced pneumonia, may be to blame. Other alternate diagnoses include chronic bronchial disease or pulmonary edema.