PETS - About your furry
friends
Animals produce different
types of substances that are the primary culprits in causing allergy. In
general, proteins in the urine, saliva or dander (dead skin flakes) of
pets provoke immune reactions in people with allergies. In cats, for
example, the main substances that cause problems are proteins found in
cat saliva, which get mixed up in house dust. In rodents such as mice or
rats or guinea pigs, it seems that the urine contains the predominant
substances that cause allergy.
DANDER
The problem is not with
the pet's hair. It is the dander, or microscopic scales of dead skin
(similar to, but much smaller than the dandruff on the human scalp)
which pets are constantly shedding that is the cause. They are so tiny
that you seldom, if ever, know that they are circulating in the air or
laying on the furniture and carpets.
URINE
Recent studies indicate
that urine (protein), from cats and dogs as well as from ferrets, guinea
pigs, hamsters, and mice, contain allergens which can also trigger
allergic reactions.
Biological
contaminants can come from both
outside and inside the home. Sources include house dust mites, animal
dander, dust, pollen, cockroaches and molds, all of which can cause an
allergic reaction. Some organisms can contaminate water sources, and
become airborne through humidifiers
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By-products of the
building's heating, ventilation and
air conditioning (HVAC) system, cooking and cigarette smoke.
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Vapors "outgassing"
from synthetic building materials,
glues, carpets, furnishings and decorating materials.
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Vapors from perfumes
and some household cleaners.
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The occupants: people
and pets breathe out carbon dioxide
and pets produce animal dander.
-
Outdoor air pollution
entering into the home.
Toxoplasmosis
(Toxoplasma gondii)
Toxoplasma gondii is
found throughout North America and can infect almost any warm-blooded
animal or bird, and humans. Infection with T. gondii, a condition
called toxoplasmosis, can be very serious in humans. T. gondii
can be passed from a pregnant woman to her fetus and cause abortions and
congenital defects. In children and adults it can cause other signs, and
is sometimes fatal. It can cause severe disease in persons with poor
immune systems such as those undergoing chemotherapy or infected with
human immunodeficiency virus (the virus that causes AIDS). The cases of
toxoplasmosis in the United States had been declining to 350 cases
annually in the early 1990’s. With the AIDS epidemic, the number of
cases has increased. Surveys in the United States suggest 30% of cats
and 25-50% of people have been infected (most clear the infection with
no or few symptoms).
What are the signs and
symptoms of toxoplasmosis in humans?
Humans can become
infected either in utero, or by accidental ingestion of the oocysts. If T.
gondii passes through the uterus of an infected pregnant woman to
her fetus early in the pregnancy, spontaneous abortion is common. If the
infection occurs later in pregnancy (10-24 weeks of gestation) the
infant may have serious or fatal congenital defects including
hydrocephalus, blindness, and mental retardation. Most infected pregnant
women do not have symptoms. Approximately 60% of infected pregnant women
will pass the infection to their fetus.
People infected through
ingestion of oocysts may be listless and have fever, enlarged lymph
nodes and less commonly, inflammation of the heart.
|
Cockroaches
and flies may serve as transport hosts for T. gondii,
carrying cat’s fecal material on their bodies. Controlling
these pests may help in preventing the spread of T. gondii. |
Diagnosis is generally
made through serologic (blood) testing.
References
James T. Li, M.D., a Mayo
Clinic board-certified allergist and internist
Dubey, JP. Toxoplasmosis.
Zoonosis Updates. American Veterinary Medical Association, 1995:144-149.
Georgi, JR; Georgi, ME.
Canine Clinical Parasitology. Lea & Febiger, Philadelphia PA;
1992;81,87-88.
Griffiths, HJ. A Handbook
of Veterinary Parasitology. University of Minnesota Press, Minneapolis
MN; 1978;31-33.
Hendrix, CM. Diagnostic
Veterinary Parasitology. Mosby, Inc., St. Louis MO; 1998;22-23, 279-280.
Lappin, MR.
Toxoplasmosis. Perspectives 1993(Charter Issue):8-16.
Lappin, MR.
Immunodiagnosis and Management of Clinical Feline Toxoplasmosis.
Presented at the Wisconsin Veterinary Medical Association Convention,
1994.
Lindsay, DS; Blagburn,
BL; Dubey, JP. Feline toxoplasmosis and the importance of the Toxoplasma
gondii oocyst. Compendium on Continuing Education for the Practicing
Veterinarian, 1997; 19(4):448-461.
Sherding, RG.
Toxoplasmosis, Neosporosis, and Other Multisystemic Protozoal
Infections. In Birchard, SJ; Sherding, RG (eds): Saunders Manual of
Small Animal Practice. WB Saunders Co., Philadelphia PA; 1994;141-145.
Sousby, EJL. Helminths,
arthropods and protozoa of domesticated animals. Lea & Febiger,
Philadelphia PA; 1982;670-682.
