Fungi are a large family that includes mushrooms. They live in soil and
organic material. Many types of fungi spread via airborne spores. Fungus
spores, which resist heat and can live for long periods without water, gain
entrance to the body through the respiratory tract or a break in the skin.
Fungal diseases can be divided into two categories. The first are fungi that
affect only the skin or mucous membranes, such as ringworm and thrush. In the
second category, the fungus is widespread and involves the liver, lungs, brain,
and other organs, in which case the disease is systemic.
Cats can get a variety of intestinal parasites, including some that are commonly referred to as “worms.” Infestations of intestinal worms can cause a variety of symptoms. Sometimes cats demonstrate few to no outward signs of infection, and the infestation can go undetected despite being a potentially serious health problem. Some feline parasitic worms are hazards for humane health as well.
Systemic diseases are caused by fungi that live in soil and organic
material. Spores, which resist heat and can live for long periods without
water, gain entrance through the respiratory system or through the skin at the
site of a puncture. Systemic fungal diseases tend to occur in chronically ill
or poorly nourished cats.
Fungal diseases are difficult to recognize and treat. X-rays, biopsies,
fungal cultures, and serologic blood tests are used to make a diagnosis.
Suspect a fungus when an unexplained infection fails to respond to a full
course of antibiotics. Although many
systemic fungal agents can both infect humans and cats, only Sporotrichosis has been shown
to infect humans following direct exposure to infected cats.
This disease, caused by the yeastlike fungus Cryptococcus neoformans, is the
most common systemic fungal infection of cats. It tends to occur in young adult
animals. It is acquired by inhaling spores found in soil heavily contaminated
by bird droppings, especially those of pigeons. The likelihood of infection is
increased if the cat has an immune deficiency. However, not all cats who
develop cryptococcosis are immune depressed.
Nasal cryptococcosis occurs in 50 percent of cases. Signs include sneezing, snuffling, a mucoid to bloody discharge from
one or both nostrils, coughing, and obstructed
breathing. Flesh-colored polyplike growths may protrude from the nose. The
infection may extend to the brain and cause fatal meningitis with neurological
signs such as circling and seizures. Ocular damage,
including blindness, may also be noted.