All About: Cat Toxoplasmosis
What You Should Know About Feline Toxoplasmosis
Toxoplasmosis is a disease caused by a microscopic parasite
called Toxoplasma gondii. It is not a new disease, having first been
discovered in 1908. Since its discovery, toxoplasmosis has been found in
virtually all warm-blooded animals including most pets, livestock, and
human beings. Nearly one-third of all adults in the U.S. and in Europe have
antibodies to Toxoplasma, which means they have been exposed to this
parasite.
How do people become infected with Toxoplasmosis?
There are 3 principal ways Toxoplasma is transmitted:
Directly from pregnant mother to unborn child when the mother
becomes infected with Toxoplasma during pregnancy.
Consumption and handling of undercooked or raw meat from
infected animals.
Ingestion of food or water or inhalation of dust contaminated with a
very resistant form of Toxoplasma called the oocyst (pronounced
o-o-cyst) during a period called Stage F.
Pigs, sheep, goats, and poultry are sources of meat commonly infected with
Toxoplasma. Toxoplasma in meat can be killed by cooking at 152ºF
(66ºC) or higher or freezing for a day in a household freezer.
Of all the infected animals tested, only cats are the perfect hosts for the
production of the infectious and resistant Toxoplasma oocysts. The oocyst,
released from the intestine of cats in their feces, is very hardy and can
survive sleet, freezing, and even several months of extreme heat and
dehydration. Moreover, oocysts can be carried long distances by wind and
water. Thus the threat of toxoplasmosis can be greatly reduced when
Toxoplasma oocysts are destroyed.
Dangers of toxoplasmosis in human beings
There are two populations at high risk for infection with Toxoplasma;
pregnant women and immunodeficient individuals. In the United States it is
estimated that approximately 3,000 children are born infected with
toxoplasmosis every year.
Although the majority of infected infants show no symptoms of
toxoplasmosis at birth, many are likely to develop signs of infection later in
life. Loss of vision, mental retardation, loss of hearing, and death in severe
cases, are the symptoms of toxoplasmosis in congenitally infected children.
Ideally, women who are in frequent contact with cats should be
serologically tested for Toxoplasma gondii before becoming pregnant,
because, if they are already seropositive, they are not at risk of acquiring a
primary, acute infection during pregnancy.
The epidemic of Acquired Immune Deficiency Syndrome (AIDS) caused
by the human immunodeficiency virus (HIV) has created an expanding
population of susceptible individuals.
Usually, people suffering from both AIDS and toxoplasmosis have been
exposed to the Toxoplasma parasite earlier in life and the HIV infection
simply allowed the Toxoplasma parasite to grow unchecked.
These patients develop neurologic diseases and can experience convulsions,
paralysis, coma or even die from toxoplasmosis even after treatment is
administered.
Pets can be companions for AIDS patients suffering from toxoplasmosis
and usually pose no additional threat from further transmission of
Toxoplasma parasites.
Since cats usually shed Toxoplasma in their feces for only one to two
weeks in their lives and because oocysts are not infectious immediately after
passage from the cat, the risk of human Toxoplasma infection from pet cats
can be greatly reduced with minimal prevention.
To prevent exposure to Toxoplasma:
Follow these steps, especially during pregnancy, to prevent exposure to
Toxoplasma:
Change litter daily before any Toxoplasma oocysts can "ripen" and
become infectious (Stage F).
Dispose of used litter safely, preferably in a sealed plastic bag. If
pregnant, avoid changing the litter box if possible (or use rubber
gloves).
Wash vegetables thoroughly before eating, especially those grown in
backyard gardens.
Boil water from ponds or streams before drinking when camping or
hiking.
Cover sand boxes when not in use to discourage cats defecating in
them.
Wash hands with soap and water after working with soil or after
handling raw or undercooked meat.
Cutting boards, knives, and the sink and counters should be washed
well after cutting meat.
When cooking, avoid tasting meat before it is fully cooked. Cook
meat thoroughly until the internal temperature reaches 152ºF (66ºC)
in a conventional oven. Microwaving is not a sure way to kill
Toxoplasma in meat.
How do cats become infected with Toxoplasma?
Although cats can be infected by the same means as humans, the most likely
sources of toxoplasmosis in cats is from eating mice, birds, and other small
animals that are infected with the Toxoplasma parasite. For indoor cats, the
most likely source is uncooked meat scraps.
When a cat is exposed to Toxoplasma parasites through the consumption of
infected meat or tissues, the cat can eventually excrete millions of
Toxoplasma oocysts in its feces each day.
This release of oocysts can continue for up to two weeks. Oocysts in feces
become infectious (reach Stage F) after one to two days. Since most cats
do not leave feces on their fur for two days, it is unlikely that humans
become infected from direct contact with cats themselves.
Because cats usually exhibit no signs of illness while passing oocysts, it is
difficult to determine when a particular cat's feces may be infectious to
people or other mammals.
Most adult cats will not pass oocysts every year. Although the majority of
infected infants show no symptoms of toxoplasmosis at birth, many are
likely to develop signs of infection later in life.
Loss of vision, mental retardation, loss of hearing, and death in severe
cases, are the symptoms of toxoplasmosis in congenitally infected children.
Ideally, women who are in frequent contact with cats should be
serologically tested for Toxoplasma gondii before becoming pregnant,
because, if they are already seropositive, they are not at risk of asymptoms
of toxoplasmosis, there have been cases in cats associating toxoplasmosis
with pneumonia, liver damage, and loss of vision.
Why some cats show symptoms and other cats do not is not known.
Concurrent infection with other diseases (feline leukemia, feline AIDS) can
aggravate toxoplasmosis in cats. Treatment can be effective if the disease is
diagnosed early. A blood test for Toxoplasma antibodies helps in diagnosis
of toxoplasmosis in sick cats.
To help prevent Toxoplasma infection in cats, follow these steps:
Keep cats indoors and do not allow them to hunt rodents and birds.
Feed cats only cooked meat or processed food from commercial
sources.
At present there is no vaccine for toxoplasmosis in cats. Efforts are,
however, underway to market a vaccine to prevent Toxoplasma oocyst
shedding by cats.
Does your kitty just play with it's food?
If so, then perhaps you should consider providing your
Precious feline companion with a Dining Experience they
will enjoy eating
Your Kitty Deserves the Ultimate in Feline Cuisine
Check out Alfred's
Favorite Feline Cuisine Here
See Also:
Back to All Cat Care & Kitty Fun Stuff
Search Our Site for Really Cool Stuff about Cats and Pets:
