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Invasive Tissue Parasites 211

■ Racking cough with blood that is sometimes sure that both pets and wild animals can’t defecate
diagnosed as tuberculosis on the soil where the plants are grown. As added
■ Jaundice as a result of pressure by an enlarged cyst insurance against becoming infected, personal pro-
that might obstruct bile drainage tective equipment, particularly disposable gloves, is
mandatory when gardening or removing droppings
and disinfecting the kennel.
Treatment and Prevention
■ Prevention of Animal Infections
Remember that hydatid disease can lead to eventual
Controlling tapeworm infections in domestic
death without adequate medical treatment. Therefore, dogs, working dogs, and a number of pet species is
an accurate diagnosis is important, as a number of symp-
paramount. Deworming dogs on a routine basis is
toms and signs can be attributed to other medical condi- important to prevent the spread of echinococcosis.
tions. A life-threatening allergic reaction (anaphylaxis)
The careful disposal of excrement, particularly
resulting from a heavily infested organ that may fail or for dogs being treated for tapeworm infection, is
a cyst may rupture and cause a serious consequences.
extremely important. It should be realized that in-
Both phases of the tapeworm’s life cycle, the definitive fected dogs often have no symptoms while suffering
and the intermediate host infections, must be broken in
from a tapeworm infection and infected dogs may
order to prevent infection since the life cycle is a com- show few or no signs of infection and may appear
plex sequence. Guidelines that will help to prevent infec-
happy and healthy.
tion include:
In rural areas dogs may have exposure to wild-
■ Personal Safety life and animal carcasses and this puts them at
The most important facet of preventing infection increased risk for contracting an infection. Make
includes washing hands before eating, drinking, it a practice to feed dogs with only commercially
and smoking and after gardening or handling ani- prepared dog foods from reputable manufactur-
mals. Wash hands thoroughly, particularly after ers. Do not feed raw or cooked waste meats that
cleaning dog pens, after which the waste is most include organs and entrails to a dog. This precau-
often buried or burned. Even after handling or be- tion extends to animal products obtained from a
ing in contact with a dog or its feeding containers, butcher or supermarket. In addition, dogs should
wash hands thoroughly with warm water and soap. be restrained to prevent them from going into areas
Children should be taught the dangers of failing to where feces from wild animals, sheep, and cattle
wash their hands effectively and very small children may have contaminated the ground. If dogs are not
should be supervised when they wash their hands. free to roam, there is less likelihood of their coming
Home vegetable gardens should be fenced to make into contact with animal feces.

SUMMARY

Both nematodes and cestodes are capable of invading Trichinosis may also be known as trichinellosis
tissues of the body, causing extensive immune responses and trichina infection. The causative organism is the
and tissue damage. The trichinella species (Trichinella intestinal nematode worm Trichinella spiralis, and it
spiralis) chiefly is ingested with poorly cooked food and requires two hosts in the life cycle. Infection occurs
during the life cycle of the organism; the muscles are in- when encysted muscle, particularly from pork, is eaten
vaded and the larval forms encyst in the muscles, caus- and the infected meat breaks down to release the organ-
ing pain to the infected victim. Hydatifiorm diseases are isms that then infect the muscle tissue. The relation-
caused by a cestode, or tapeworm, contracted through ship between pork and associated disease in humans
contaminated materials and may invade the body of a hu- was established by James Paget in 1821. Adult worms
man, including the nervous system. These are caused by were observed in 1859 and 1860, where a positive
Echinococcus granulosus and Echinococcus multilocularis. link between eating raw port and the development of