Fungal Infections in Cats

Funguses (also called fungi) are parasitic, spore-producing organisms. They obtain their nourishment by absorbing food from the hosts on which they grow. Many species of fungus exist within the environment, but just some cause infections. the first source of most infections is soil. Fungal infections are often acquired by inhalation, ingestion, or through the skin (for example, through a cut or wound).

Some fungal infections can cause disease in otherwise healthy animals, while others require a number that’s sick, weakened, or immunocompromised to determine infection. Prolonged use of antibiotic drugs or immunosuppressive agents appears to extend the likelihood of some fungal infections. The infection itself could also be localized, or it’s going to affect the whole body. generally, fungal infections affecting the skin (such as ringworm) are common in cats, while generalized fungal infections are very rare.


Aspergillosis may be a mycosis caused by several Aspergillus species. it’s primarily a respiratory tract infection that will rarely spread throughout the body. Aspergillosis is found worldwide and in most livestock also as in many wild animals; however, the susceptibility to fungal infections varies among species. cavity, sinus, and lung forms are described in domestic cats. Cats that are already stressed by disease (such as viral infection) or immunosuppressed could also be more likely to become infected. Signs are nonspecific and include inflammation of the sinuses, facial swelling, and pneumonia. The fungus also can invade the central systema nervosum and cause neurologic signs (such as seizures). Establishing an accurate diagnosis is often difficult and should require x-rays, computerized tomography, and laboratory testing. Surgery and antifungal drugs are usually recommended to treat aspergillosis; however, the outlook depends on the general condition of the cat and therefore the extent of infection.


Candidiasis may be a localized fungal disease affecting the mucous membranes and therefore the skin. it’s distributed worldwide during a sort of animals and is most ordinarily caused by species of the yeast-like fungus, Candida albicans. Candidiasis is rare in cats, but has been related to oral and upper respiratory illness, lesions of the attention, infection of the space between the lungs and chest wall, intestinal disease, and bladder infection.

Factors that will predispose an animal to infection include injury to any of the mucous membranes, the utilization of catheters, administration of antibiotics, and immunosuppressive drugs or diseases.

Signs of infection are variable and nonspecific (for example, diarrhea, weakness, skin lesions) and should be associated more with the first or predisposing conditions than with the Candida infection itself. An ointment or topical application could also be useful in the treatment of oral or skin candidiasis. Your veterinarian can also recommend different drugs given orally or by injection for the treatment of infected cats.

Coccidioidomycosis (Valley Fever)

Coccidioidomycosis may be a dust-borne, noncontagious infection caused by the fungus Coccidioides. Infections are limited to dry, desert-like regions of the southwestern us and similar geographic areas of Mexico and Central and South America. Inhalation of fungal spores (often carried on dust particles) is that the only established mode of infection. Epidemics may occur when rainy periods are followed by drought, leading to dust storms. Infections are uncommon in cats.

Coccidioidomycosis is primarily a chronic respiratory illness. Infected cats most frequently have skin problems (draining skin lesions, lumps under the skin, abscesses), fever, lack of appetite, and weight loss. Less common signs in cats include difficulty breathing, lameness, neurologic signs, and eye abnormalities. The infection spreads to multiple locations within the body in approximately half infected cats. A diagnosis is predicated on blood tests or identification of the fungus in tissue samples from the animal.

Treatment involves future antifungal medications. The prognosis is guarded, but cats with skin infections may answer treatment. there’s no known prevention aside from decreasing your pet’s exposure to abandon soil and mud the maximum amount as possible in areas where the fungus occurs.


Cryptococcosis may be a fungal disease that will affect the tract (especially the nasal cavity), central systema nervosum, eyes, and skin (particularly of the face and neck) of cats. it’s caused by the fungi Cryptococcus neo forms and Cryptococcus gattii, which are found worldwide in soil and bird manure, especially in droppings. Transmission is by inhalation of spores or contamination of wounds.

Cryptococcosis is commonest in cats, although it also occurs in other domestic and wild animals. In cats, upper respiratory signs following infection of the cavity are commonest. The signs often include sneezing; bloody, clear, or pus-filled nasal discharge; polyp-like mass(es) within the nostril; and a firm swelling under the skin and over the bridge of the nose. Areas of small raised bumps and nodules may affect the skin; these may feel soft (liquid-filled) or firm. These areas may ulcerate, leaving a raw surface. Neurologic signs related to cryptococcosis of the central systema nervosum include depression, changes in temperament, seizures, circling, slight paralysis, and blindness. Eye abnormalities can also develop.


Long Term nasal discharge consisting of clear fluid, blood, mucus, and/or pus

Firm swelling under the skin and over the bridge of the nose

Polyp-like mass(es) within the nostril

Skin lesions (common)

Raised bumps or nodules which will be firm or soft

Larger lesions tend to ulcerate, leaving a raw surface

Neurologic signs


Changes in temperament



Slight paralysis


Eye abnormalities

Dilated unresponsive pupils

Blindness thanks to detachment of the retina 

Inflammation of the tissues of the attention 

Cryptococcosis is diagnosed using microscopic evaluation of samples taken from affected areas or through other laboratory tests. Various antifungal drugs could also be prescribed for the treatment of cryptococcosis. Most affected pets require prolonged treatment (up to many months), counting on the severity and extent of the disease. Treatment for cryptococcosis may include surgery to get rid of lesions within the cavity or on the bridge of the nose. The outlook for cats that also are infected with feline leukemia virus or feline immunodeficiency virus is guarded because these cats have a better likelihood of treatment failure.


Histoplasmosis may be a noncontagious infection caused by the fungus Histoplasma capsulatum, which is found worldwide. This soil fungus is cosmopolitan (particularly by bird and bat populations) within the midwestern and southern us, especially in river valleys and plains. Infection occurs when spores within the air are inhaled. The lungs and therefore the lymph nodes within the chest are the sites of primary infection. The organisms enter the bloodstream from these sites and become dispersed throughout the body; they’ll localize in bone marrow or the eyes.

The signs vary and are nonspecific, reflecting the varied organ involvements. Occasionally, the infection only involves the lungs, and cats show signs of fever, labored breathing, and coughing. The lung infection may resolve on its own. However, it’s common for the respiratory tract infection to increase to other tissues, a more serious sort of disease that involves an outsized number of organs and body systems. The organs most frequently affected are the lungs, intestine, lymph nodes, liver, spleen, and bone marrow. Signs of illness like depression, fever, and poor appetite are common, also as difficulty breathing, chronic diarrhea, intestinal blood loss, anemia, and weight loss. Infection of the bones, eyes, skin, and central systema nervosum may occur. Diagnosis requires identification of the fungus in body fluids or tissues. Blood tests or x-rays can also be necessary.

Treatment of widespread histoplasmosis is difficult. It requires the utilization of antifungal drugs and supportive treatment, like adequate nutrition, additional fluids (hydration), and control of secondary bacterial infections. Antifungal treatment must be continued for prolonged periods of your time.


Mycetomas are infections of the skin and underlying tissues that have the looks of nodules or tumors. When such lesions are caused by funguses, they’re referred to as mycotic mycetomas. The fungus multiplies within the lesions and organizes into aggregates referred to as granules or grains. Granules could also be of varied colors and sizes, counting on the species of fungus involved. Mycetomas are rare in cats.

Most eumycotic mycetomas are confined to the tissue beneath the skin, but some could also be extensions of fungal infections within the abdomen. In cats, mycetomas are usually characterized by skin nodules on the legs and feet or the face. When the feet or limbs are involved, the infection may reach the underlying bone.

A mycetoma is diagnosed by identifying the fungus within its contents. A tissue biopsy could also be necessary. Skin mycetomas, while not life-threatening, are often difficult to resolve. The outlook for abdominal mycetomas is guarded because tissue involvement is typically extensive. Your veterinarian will recommend the simplest treatment options, which can include surgical removal (including amputation) or antifungal medication.


Blastomycosis, caused by the fungus Blastomyces dermatitidis, is usually limited to geographically restricted areas within the Mississippi, Missouri, Tennessee, and Ohio basins and along the good Lakes and therefore the St. Lawrence Seaway. It also occurs within the Pacific Northwest. Beaver dams and other habitats where the soil is moist, acidic, and rich in decaying vegetation may function as the ecologic niche for the organism, which has also been found in pigeon and bat feces. Cats are one among the foremost commonly affected species (in addition to people and dogs), but cats develop signs of blastomycosis in multiple organs far less commonly than dogs do.

The infective sort of blastomycosis is usually inhaled into the lungs. When respiratory defenses are overwhelmed or immunosuppressed, the infection spreads from the lungs through the bloodstream. Infection can occur through the skin, but spread from a lung infection is far more common.

Affected animals have signs like fever, lethargy, poor appetite, and weight loss. Lung involvement results in exercise intolerance, cough, and difficulty breathing. The peripheral lymph nodes could also be enlarged. Bone involvement may occur and end in lameness. Central systema nervosum infection may cause behavior changes, seizures, coma, or overtime. Infection of the urogenital tract occasionally may occur and cause signs like blood within the urine or difficulty urinating. Eye involvement can cause pain, light sensitivity, and glaucoma. Involvement of the retina may cause blindness. Draining nodules or large abscesses (pockets of pus) could also be found within the skin. If blastomycosis occurs within the urinary or reproductive systems, bloody urine or difficulty urinating could also be seen.

Your veterinarian may suspect blastomycosis supported your cat’s signs of illness, especially coughing or trouble to breathe. Chest x-rays are often performed. The diagnosis is often made by identifying the fungus in affected tissue or with blood or urine tests.

Treatment of blastomycosis is predicated on the severity of the condition and other factors that have got to be evaluated by a veterinarian. Treatment is aimed toward relief of specific signs (such as difficulty breathing, coughing, or eye problems) and elimination of the fungus from the body. Treatment may include one or more antifungal drugs, which are given for an extended period (often 2 months or more) until the active disease isn’t apparent. Relapses may occur.


Phaeohyphomycosis may be a general term for infection by any variety of pigmented funguses of the Dematiaceae. Infection may result from fungal contamination of tissue at the location of an injury. Phaeohyphomycosis is rare in cats. In most cases, the infection is confined to the skin and tissues beneath the skin. Slowly enlarging masses beneath the skin are found on the toes, ears, face, and therefore the lining of the nasal passages. Rarely, it can affect the central system of nerves. The nodules may ulcerate and have draining tracts. Phaeohyphomycosis is often difficult to treat. Surgical removal of the lesion is often a cure. Treatment with antifungal drugs could also be considered in cases when surgery isn’t possible.


Rhinosporidiosis may be a chronic, nonfatal infection, primarily of the liner of the nasal passages and, occasionally, of the skin. it’s caused by the fungus Rhinosporidium seeberi. Uncommon in North America, it’s seen most frequently in India, Africa, and South America.

Infection is characterized by polyp-like growths which will be soft, pink, crumbly, lobular with roughened surfaces, and enormous enough to obstruct or close off the nasal passages. The skin lesions could also be single or multiple, attached at a base, or have a stem-like connection.

This infection is diagnosed by identifying the fungus during a biopsied tissue sample. Surgical removal of the lesions is taken into account to be the quality treatment, but recurrence is common.


Sporotrichosis may be a sporadic, long-term disease caused by Sporothrix schenckii. The organism is found around the world in soil, vegetation, and timber. In the US, this fungus is most ordinarily found in coastal regions and river valleys. Infection usually results when the organism enters the body through skin wounds via contact with plants or soil or penetrating foreign objects, like a pointy branch. Transmission of the disease from animals, especially cats, to humans can occur. Cats can shed particularly large amounts of fungus from infected wounds and in their feces.

Sporotrichosis is more common in cats than in other species. The infection may remain localized to the location of the entry (involving only the skin) or it’s going to spread to nearby lymph nodes. In cats, affected areas are presumed to occur on the top, especially the bridge of the nose or the ears. Although the generalized illness isn’t seen initially, the future infection may end in fever, listlessness, and depression. Rarely, the infection will spread through the bloodstream from the initial site of inoculation to the bone, lungs, liver, spleen, testes, alimentary canal, or central systema nervosum.

Sporotrichosis is usually diagnosed by identifying the fungus during a sample of affected tissue or with culture. Long-term treatment with antifungal drugs (continued 3 to 4 weeks beyond apparent cure) is typically recommended. Because sporotrichosis is often passed from your pet to you, strict hygiene must be observed when handling animals with suspected or diagnosed sporotrichosis. The cat’s caretaker appears to be more likely to become infected than other members of the household. If your cat is diagnosed with sporotrichosis, ask your veterinarian about the precautions you and each member of your family should take while your pet is ill.