Encephalitozoonosis (microsporidiosis) in Cats
Encephalitozoon cuniculi (E. cuniculi) is a protozoal parasitic infection which spreads and creates lesions on the lungs, heart, kidneys, and brain, significantly effecting their ability to function normally. It is rarely seen parasitic infection in cats -- occurring more commonly in rabbits and dogs -- but is still of concern in cats, as cats spend time outdoors with other cats and in environments that are inhabited by other animals, like wild rabbits.
This disease is also commonly called microsporidiosis, as the E. cuniculi is a parasite belonging to the species of microsporidia. It appears to be acquired by the oronasal (mouth and nose) route, when an animal licks/sniffs the spore-infected urine of another animal. For this reason, animals that are kenneled are at greater risk for it. However, because microsporidia can survive for extended periods in the environment, it is reasonable to assume that almost any cat that goes outdoors is susceptible to infection. Conversely, cats that are kept indoors are at a greatly decreased risk of acquiring this parasite.
Treatment is experimental, with supportive therapy being the most dominant treatment. In most cases infected cats will recover fully without medical treatment, but it is often fatal when acquired by kittens (most often acquired while developing in the womb, or while nursing). Kittens may be stillborn, or will die while young from failure to thrive.
In addition, this parasitic infection is zoonotic and is therefore contagious to humans, particularly those who are immunocompromised. Sanitizing the environment is essential; a 70 percent ethanol solution should be used to clean up any infected urine and throughout the cat's living area.
Symptoms and Types
Neonatal infection (appears around three weeks of age)
- Stunted growth
- Poor hair coat, small size
- Failure to thrive
- Advances to kidney failure
- Neurological complications
- Brain abnormalities
- Aggressive behavior
- Progress to kidney failure
- E. cuniculi in
spore-infected urine, usually spread/acquired by licking and sniffing
Your veterinarian will conduct a thorough physical exam of your cat after taking a complete history from you. You will then need to provide as much background information as possible about your cat's health and all of the symptoms leading up to the visit. If your cat has recently given birth, or you have kittens being treated, the kittens may be very small with a poor, dull-looking hair coats.
Because there are symptoms that are similar to other diseased conditions, such as uncharacteristic aggression, your veterinarian may want to test for rabies, as well as for toxoplasmosis. If your cat is an adult, it may have limited vision, complete blindness, or it may be having occasional seizures. Your veterinarian will order a chemical blood profile, a complete blood count and a urinalysis to see which organs are being most affected by the parasitic infection. The infectious spores can be seen in urine that has been stained to make the spores visible under a microscope.