Fungal Diseases in Cats
Cutaneous cryptococcosis, which occurs in 25 percent of cases, frequently
produces a firm swelling over the bridge of the nose. The face and neck are
other common sites.
Neurologic cryptococcosis can show a variety of signs, depending on where
the infection is located. These include blindness, seizures, and vestibular
signs, such as incoordination or a head tilt. The diagnosis can be made by
fungus culture or tissue biopsy. Often, the organisms can be identified in a
smear from the nasal discharge. A cryptococcus
latex agglutination test is available.
Treatment: Oral antifungal drugs of the imidazole group, such as
ketoconazole, are effective when started early in the course of the disease.
Fluconazole and itraconazole are newer drugs that are far better tolerated by
cats. These drugs are slow acting. Treatment is prolonged. If those drugs are
not successful, amphotercin B or flucytosine can be tried, but they are
medications of last resort because they have many serious side effects.
This disease is caused by a fungus found in the central United States near
the Great Lakes, the Appalachian Mountains, Texas, and the valleys of the
Mississippi, Ohio, and St. Lawrence Rivers. In these areas, the nitrogen-rich
soil facilitates growth of the causative fungus (Histoplasma capsulatum).
In the majority of cats, histoplasmosis is an insidious disease with fever,
loss of appetite, weakness, weight loss, and
debilitation. The liver, respiratory system, eyes, and skin may be involved. Lameness may be noted.
Treatment: Successful treatment with antifungal drugs, such as itraconazole,
depends on early diagnosis. Despite treatment, most cats die from this
infection. Mild respiratory cases have the best prognosis
This uncommon skin infection is caused by fungus spores in the soil. These
spores usually gain access through a break in the skin. Other routes of
infection are by ingesting or inhaling spores. The disease is most common among
male cats who prowl in thorny underbrush or sharp prairie grass. Most cases are
reported in the northern and central portions of the United States, along river
valleys and in coastal areas.
A nodule forms at the site of a skin wound, usually on the feet or legs, the
face, or the base of the tail. The hair over the nodule falls out, leaving a
moist, ulcerated surface. In some cases there is little surface reaction, but
you may see several small firm nodules beneath the skin that appear to form a