Overview of Blastomycosis in Cats
Blastomycosis is a systemic disease caused by a fungus present in the soil of certain regions, such as Mississippi, Missouri and Ohio River Valley. The organism is present in the soil and infection occurs by inhalation of the fungus. Once infection is established in the lung, the fungus changes its characteristics by converting from the mycelial form into the yeast form and spreads to other organs causing a disseminated infection.
Below is an overview of Blastomycosis in Cats followed by in-depth details about the diagnosis and treatment of this condition.
This fungus exists in two different forms:
Hunting cats that spend a lot of time outdoors and live in endemic areas are at risk for inhaling this organism and developing the disease.
Some animals may be infected but not show clinical signs for a long time. These animals are not a risk for contagion of other animals and people because the stage of the organism present in the animal’s tissues is not that of an infectious stage.
If left untreated, these cats can become seriously ill. Cats may develop infection in the kidneys, eyes, brain and bones. According to the organ that is affected, the clinical signs may vary. They may have ocular problems or neurological signs like seizures and head tilt. In some cats lameness may be the primary complaint due to infection in the bones.
What to Watch For
Diagnosis of Blastomycosis in Cats
Suspicion of blastomycosis comes from the history of living in an area at risk for this infection, especially in animals that hunt or spend a lot of time outside. Clinical signs may not be very specific.
Treatment of Blastomycosis in Cats
Home Care and Prevention
It is important that you administer the medications as instructed by your veterinarian and that you monitor the appetite and bowel movements of your pet. Some drugs may induce nausea and vomiting. If your pet stops eating, your veterinarian needs to be notified immediately.
There is no vaccine or effective way of disinfecting the contaminated soil.
In-depth Information on Blastomycosis in Cats
Other medical problems can cause symptoms similar to those encountered in cats with blastomycosis. Your vet will exclude these conditions as necessary before establishing a diagnosis of blastomycosis:
Blastomycosis is a systemic disease caused by a fungus (blastomyces dermatidis) present in the soil of certain geographic regions (Mississippi, Missouri and Ohio River valleys). Dogs and people are most commonly infected, but cats can develop systemic disease.
Infection occurs by inhalation of spores from the “mycelial” form of the organism found in the environment, especially moist soil. After the organism becomes established in the lung, dissemination throughout the body occurs. Blastomycosis is endemic in the Mississippi, Missouri and Ohio River valleys.
The “yeast” form of the organism (found in infected body tissues) is not contagious, and thus the disease is not readily transmissible between animals or from animals to people.
The prognosis depends on the extent and severity of lung involvement. Blastomycosis affects the lungs (80 percent of cases), eyes (40 percent of cases), skin (20 to 40 percent of cases), and bones (30 percent of cases).
Most affected animals have systemic symptoms such as fever, lethargy, loss of appetite, and weight loss. Lung involvement leads to respiratory symptoms such as exercise intolerance, cough, and difficulty breathing.
The animal’s peripheral lymph nodes often are enlarged (found under the neck, in the shoulder region and behind the knee). Bone involvement may occur and result in lameness. Infection of the urogenital tract (e.g. the prostate gland in males) ccasionally may occur and cause clinical symptoms (e.g. blood in the urine, difficult urinations). Nervous system involvement may cause seizures, uncoordination, head tilt, and other symptoms.
Eye involvement can lead to squinting due to pain and light sensitivity. Involvement of the retina may lead to blindness. Involvement of the iris of the eye may be complicated by glaucoma (i.e. high pressure within the eye). Draining nodules may be found in the skin, and microscopic examination of this material often discloses the organism and yields a diagnosis.