Although they should like something you
might find on an elephant’s face...zoonoses are actually diseases or infections
that are transmitted from animals to humans. It is important to be aware of
zoonoses and know how to prevent them, especially in families with small
children or individuals with compromised immune systems.
Internal Parasites
Roundworms: There are many
species of this intestinal worm. They are quite common in puppies and kittens as
they can be passed through their mother’s milk. The microscopic eggs are shed in
the feces and people (especially young children) can get them by ingesting dirt
or sand. In humans, roundworms can migrate in the body and cause damage to
organs such as the retina of the eye.
Tapeworms: These are one of
the few internal parasites that can be seen without the use of a microscope.
They resemble grains of rice or sesame seeds and are found clinging to the hair
near the base of the tail. These eggs are not directly infective to people as
they have to cycle through secondary hosts such as fleas or rodents.
Tapeworm
Tapeworm Segments
Pinworms: These are human
parasites and are passed from person to person. They do not infect cats and
dogs.
Salmonella: This is a bacteria
that causes intestinal infections and is a common cause of food poisoning. Pets,
birds and especially reptiles that carry this bacteria often are not sick but
they can shed the bacteria in the feces and can cause severe vomiting and
diarrhea in people if they ingest it.
External Parasites:
Ringworm:
This is actually not
caused by a worm at all but by a fungus. It is transmitted by direct contact
with the fungal spores and causes a skin rash. Cats are common carriers of the
spores and may not show any outward sign of disease. People can also get
ringworm from other people and from soil.
Mange: This is caused by a
number of different types of microscopic skin mites and only one type is
infective to people. They can cause an itchy skin rash called scabies.
Lice:
These
parasites are very host-specific. Only human lice will infect people, not
cat/dog lice.
Cat Scratch Disease: This is
caused by bacteria that cats pick up under their claws. As cat claws are thin
and sharp, cat scratches can inject bacteria under the skin causing an infection
which, in rare cases, can have serious complications.
Viruses:
Rabies: This virus is
transmitted to humans through the bite of an infected animal and attacks the
brain. It can infect any mammal including bats, skunks, raccoons, our domestic
pets, and ourselves.
Hantavirus: This is a common
virus in deer mice and it attacks the lungs causing flu-like symptoms which can
progress to death. It is an airborne virus which can be spread to humans who
sweep up deer mouse droppings. A dog or cat cannot spread this virus from a
rodent to a person. Deer mice are more common in rural areas while most city
mice are actually field mice, which do not carry this virus.
Feline Leukemia and Feline Aids:
These are two viruses that only affect cats, not people and not any other pets.
Toxoplasmosis: Most pet
species carry this parasite, but only cats shed the organisms. Cats get this
parasite from eating rodents and raw meat and by contacting infected cats or
infected cat feces or contaminated soil. Although rare, cats can transmit this
parasite to people. It is more commonly transmitted by eating undercooked meats
or unwashed fruits and vegetables. Pregnant women should be most aware of this zoonosis because if they are exposed to the parasite for the first time while
pregnant there may be birth defects.
Parrot Fever: This disease is
also called psittacosis and is caused by a bacteria-like organism that can be
carried and spread by pet and wild birds. People catch psittacosis from contact
with infected bird droppings. This organism causes pneumonia in people which is
usually mild but can be severe in the elderly or in people with compromised
immune systems.
Prevention
Now that you know what zoonoses are, it is
equally important that you know how to prevent the transmission of them.
