The organism causing cat scratch disease is Bartonella hensclae, which was
first cultured in cats in 1992. Humans get the infection when they are scratched or bitten
by a cat carrying the causative bacteria. Most of the bacteria is in the saliva, but since
cats constantly lick their paws and their fur, the bacteria are frequently found in those
locations also.
The most common sign is small pus-filled bumps that develop within 3 to 5 days at the
site of a cat scratch or bite. It is followed by the enlargement of a regional lymph
nodes, usually in the armpit. A person that is immunocompromised needs to be especially
careful. Within two to four months after exposure, the patient will develop organ and eye
lesions, which are defined as any abnormalities in tissue. Other signs include fever,
chills, headache and anorexia. The disease often affects the bones, liver and spleen, and
may be fatal if untreated.
Usually within two weeks healing is complete without any treatment. However, if after
two weeks the bite or scratch has not healed and lymph nodes are still enlarged,
antibiotic treatment is necessary.
Wash hands every time after petting or handling a cat. Avoid cat scratches and bites.
If you are scratched or bitten, wash area thoroughly with soap and water.
Cryptosporidiosis is caused by Cryptosporidium parvum,
which is a very small protozoal parasite. The oocyst, which is the infective stage of the
organism, is ingested and multiplies in the cells lining the small intestine.
Cryptosporidium can reproduce in the intestinal cells, or can be shed in the feces of the
host, thereby releasing more infective oocysts into the environment.Wild and domestic
animals often defecate in creeks and rivers, releasing the parasite into water sources. It
has been known to get through public water filtration systems. There are many mammals that
can be infected with this organism, including humans.
Because of the nature of its life cycle, the main clinical
sign associated with Cryptosporidiosis is profuse, watery diarrhea. The diarrhea may be
bloody or mucoid. Fever, depression, and a generalized weakness may be noted. Anorexia,
dehydration, weight loss, and a rough hair coat may also be noted. There is often a
secondary infection with other pathogenic organisms, such as various bacteria.
There is no specific antimicrobial drug to treat
Cryptosporidiosis. Treatment of the disease will consist of fluid and nutritional
supportive care.
Cryptosporidium is very hardy in the environment, and
resists many common disinfectants. The best means of preventing infection is to practice
good sanitation.
Giardia is a protozoal parasite that affects birds and most mammals including man.
Giardia is found in two forms; the motile stage which is found in the small intestines and
the cyst form also known as the infectious stage.
When the cyst is ingested ( through oral/fecal contact), the cyst wall is digested away
and the motile form is released. The organism immediately divides into two. Once the
Giardia organisms reach the small intestines they attach to the wall and continue to
multiply. This process continues over the next 6 to 10 days producing diarrhea and
releasing Giardia cysts into the environment.
Diagnosis is made through fecal analysis by looking for the parasite microscopically.
Giardia is commonly found in over crowded kennels and animal shelters. Prevention of
the infection lies in cleanliness and proper disinfection. Feces should be removed often
and surfaces disinfected with a 1:32 chlorine solution, (1/2 cup household bleach to1
gallon water) or other effective cleaning solutions.
Should humans ingest the cyst, through environmental contamination, the signs and
symptoms range from intestinal gas to malabsorption. Other symptoms include abdominal
cramps, foul smelling stool, diarrhea and weight loss. Children are especially effected,
and cases as high as 50% have been noted in day care centers due to lack of proper
hygiene. Since both humans and animals serve as reservoirs, a consistent 7% of fecal
samples submitted annually are positive for Giardia.
Once diagnosed the Giardia organism is easily treatable with a 5 day oral medication
regimen. If diagnosed with Giardia, a person should consider all sources of possible
contamination and try to eliminate them.
Hantavirus Pulmonary Syndrome (HPS) is a rare but dangerous disease that is carried by
mice. The deer mouse and the cotton rat are the most common carriers. The virus is shed in
the rodent's urine, droppings, and saliva, and it can be transmitted to people when they
touch a contaminated surface and then touch their nose, mouth or food, or by a rodent
bite. The most common way it is transmitted to people is by breathing in the air when
rodent droppings are aerosolized, usually by sweeping them up. The disease is not
contagious from person to person. Dogs and cats do not get the virus, but they could carry
an infected rodent home.
The signs of HPS will appear within 1-2 weeks after exposure to the virus. The first
may be flu-like, with fever and headache. They will progress to severe muscle aches,
vomiting, dry coughing, and abdominal pain. In some cases the lungs will fill with fluid
that will cause respiratory failure and death.
The best prevention is to take these precautions:
- Never sweep or vacuum dry mouse droppings.
- Never touch a dead mouse with your bare hands.
- Avoid attracting mice by keeping garbage in containers with lids. Also never leave pet
food or water overnight.
- Try to keep rodents our of your home by sealing any holes 1/4 of an inch or larger.
Put gravel around the base of your home to prevent burrowing. If you suspect mice set
traps or poisons.
- Place woodpiles, compost, trash cans and animal food at least 100 feet away from your
house.
The treatment for HPS is supportive care. Patients are given oxygen for respiratory
distress. The earlier the disease is treated the better. If you have been exposed to
rodents and have any of the signs see a doctor immediately.
For more information see: Hantavirus at http:\\www.cdc.gov/ncidod/diseases/hanta/hps/index.htm
According to the Center for Disease Control, Lyme Disease is the most frequently
reported tick associated disease in North America. With some information, your family and
pets can have a worry free outdoor experience.
Lyme disease is an infection caused by a bacteria called Borrelia burgdorferi.
The disease is spread by the bite of a tick that is infected with the bacteria. In the
north eastern and north central U.S. the deer or bear tick is of concern.
In humans, the symptoms can be divided into two categories:early and late. The early
symptoms (three days-one month) can include fatigue, headache, muscle and joint pain,
swollen lymph nodes, and a characteristic bulls eye rash. Symptoms that can appear weeks,
months or years after the bite of an infected tick are arthritis and nervous system
abnormalities. Fever, lethargy, anorexia, lameness and swollen joints are the main signs
in dogs.
To lessen the chances of being bitten by a tick wear light colored clothing, long
sleeves, avoid tick infested areas, tape and tuck pants into shoes, use a DEET insect
repellant, walk in the center of trails. If a tick has attached itself, use tweezers to
grasp the tick as close to the skin as possible and pull back slow with a straight steady
motion; avoid crushing the tick. For dogs, there are two vaccines available.
If you suspect exposure to Lyme Disease, consult your physician. Doxycycline,
amoxicillin are used in adults and children respectively. Tetracycline, in addition to the
above, has been used in dogs with some success.
Rabies is defined as an acute viral disease which may be transmitted from animal to
animal or from animal to human by a bite or scratch of a rabid animal (which can be
skunks, bats, raccoons, cats, dogs, cattle, and foxes). The virus is carried through the
saliva of the infected animal (the dog bite is the most common way), but travels through
and affects the nervous system. Rabies is also known as "hydrophobia" (fear of
water), which is derived from the refusal of an infected animal or human to drink, since
swallowing results in horrible and painful spasms.
If any person is bitten by a suspected rabid animal, the virus can be prevented by a
series of intramuscular injections of human diploid cell vaccine and human rabies immune
globulin (HRIG) to build up immunity. If bitten around the head or neck, and the skin is
torn, or the animal was proven to be rabid, the HRIG injection is needed followed by the
Rabies vaccine. If possible, the animal should be caught and taken to an animal hospital
for ten days of observation after the first sign of illness appeared. If the illness
suggests Rabies, the animal should be killed and its head shipped to be examined for the
virus. If the animal is too aggressive and dangerous, do not attempt to get it. Instead,
call animal control and law enforcement agencies to handle the situation. Also, all local
wounds should be cleansed well with a soap or detergent solution.
The incubation period (the time between being bitten and the development of signs), can
be anywhere from ten days to one year. Once an individual starts to develop signs, he/she
goes through the following stages:
- The first one is called the Prodromal period, which usually lasts from one to five
days. Signs usually include fever, headache, malaise (a general ill feeling), muscle
aching, loss of appetite, nausea with vomiting, sore throat, cough, fatigue (tiredness),
and a tingly feeling at the site of the animal bite.
- The second stage includes a fever as high as 105 degrees Fahrenheit including any
one of these following signs: irritability, agitation (nervousness), confusion,
hallucinations, aggressiveness, strange thoughts, weakness and/or paralysis, sensitivity
to bright lights, sounds, or touch, increased salivation and lacrimation (tear
production), and the vocal cords may become paralyzed which causes the person to be unable
to talk.
- The last, (and latest), stage include: seeing double, trouble moving facial muscles
or facial paralysis, an increased production of saliva which tends to build up at the
mouth ( which gives the foaming appearance), difficulty swallowing, and trouble breathing.
Finally, the victim may slip into a coma and die.
Rabies can be prevented with the series of shots (the human diploid cell vaccine and
HRIG), after being bitten by a rabid animal. However, if someone does not get treated and
they start showing signs, their outlook (prognosis) is very poor. Death can occur four to
twenty days after the signs first occur.
Animals with Rabies exhibit many of these signs as well, so be very cautious!
Salmonella spp. infection is transmitted by the feco-oral route, mainly
by ingestion of contaminated food and water. This organism may survive in the environment
for long periods of time outside of the host, allowing fomite transmission, or
transmission from touching an infected surface. Infection rates are greatest in young
animals, animals with heavy parasite infections, rigorously wormed animals, stressed or
pregnant animals, and in group confinement situations with overcrowding and poor
sanitation.
Infected animals show little or no interest in food but may drink water freely. A fever
may range from 103 to108ºF depending on the severity of infection. Watery diarrhea with
mucus is present, with blood in the most severe cases. Dehydration will appear from
persistent diarrhea. Severe abdominal pain along with straining while urinating and
defecating is seen. Abortion occurs in some cases of Salmonellosis.
The treatment for Salmonella infections usually consists of the administration of broad
spectrum antibiotics for the systemic infections. Fluid administration helps to restore
the body's equilibrium. Blood transfusions may be needed for the severe anemia caused by
the infection. Most animals recover in three to four weeks, although shedding of the
organism often persists for up to six weeks or longer.
It is difficult to control Salmonella because of how it is spread. Proper fecal
disposal, fly control, disinfection of living areas, and proper feed storage is essential.
The isolation of new animals, carriers, and infected animals is helpful. Major changes in
feed should be accomplished gradually. Resting animals frequently while traveling, and the
avoidance of contaminated food and water should help in prevention. Vaccines for certain
strains of Salmonella are also available.
Diagnosis of roundworm infections in puppies and kittens are commonplace. One important
bit of information that many pet owners do not realize is the possibility of humans,
particularly children, contracting the parasite. Children are particularly vulnerable to
roundworm infections through association with puppies, kittens and unsanitary play habits.
The effects of these parasites in humans can be quite serious.
The intestinal parasites we are addressing are formally known as Toxocara canis
and Toxocara cati due to the host species they typically infect, puppies and
kittens respectively. The puppies or kittens are often exposed to the parasites in utero
or acquire them through the mother's milk. Their symptoms include diarrhea, poor hair
coat, lack of weight gain and often a pot belly. Effective medication can be obtained from
a veterinarian to eliminate these parasites from your pet. If the infection goes
untreated, the adult parasite's life span is only 4 months but the adult female roundworm
lays thousands of eggs a day. These eggs can survive weeks, months or even years depending
on the soil in which they are deposited.
The human is not the preferred host of these parasites but if the eggs are ingested and
hatch in the intestines the larva may migrate through the human host's tissues. This is
known as viseral larval migrans. These larva have been found in virtually every tissue of
the human body including the liver, lungs, heart and brain. Another site of migration is
the eye (ocular larval migrans ). This infection, found mainly in children, can lead to
permanent visual impairment. The clinical and pathological problems result from the
mechanical damage caused by the migrating larvae and by the severe inflammatory response
stimulated by their presence.
The signs of a roundworm infection (Toxocariasis), can vary depending on the number,
route and final destination of the larva. Typically, the visceral larval migrans is
characterized by a fever. It has also been found that the liver may become swollen. Upon
doing a blood test the physician can diagnose the infection. Sometimes the lungs are
involved with symptoms including bronchitis, asthma and pneumonia. Vision problems are
often seen in the absence of other signs or symptoms.
Prevention of this problem is two-fold: Be sure the puppies and kittens under your
control are free of parasites and their feces immediately removed from the environment.
Secondly, if your child is in an area where dogs or cats have defecated, be sure your
child does not put the dirt or any objects that have had contact with the dirt in their
mouth and wash the child's hands after exposure to the pets or soil where they play.
If a roundworm infection is suspected contact your physician. For humans no proven
treatment is available but several drugs have been found helpful in treating the symptoms.
The organism that causes the toxoplasmosis infection is Toxoplasma gondii. It is
a small intracellular protozoan parasite that can infect any warm blooded animal. The
transmission of this disease can occur across the placenta, through ingestion of raw or
undercooked meat containing cysts (the immature form of the organism) or by exposure to
the cysts in cats' feces (whether in litter or in dirt outside of the home). Pregnant
women must be aware of this problem and follow strict hygiene practice to avoid becoming
infected while pregnant.
If the T. gondii parasite is acquired by the mother early during pregnancy the
fetus may be aborted. If it is acquired later, stillbirth may occur or clinical disease
may result. The symptoms of clinical disease may occur shortly after birth or may not
appear until later in life. These symptoms include: chorioretinitis (an infection in the
retina), severe jaundice, central nervous system symptoms, blindness, or severe mental
retardation. If T. gondii is acquired after birth, it is rarely symptomatic. People
with compromised immune systems are most susceptible and may experience illness similar to
mononucleosis or suffer from severe retinal damage.
Currently there is no known treatment for the chronic or subacute congenital
infections. The acquired postnatal infection is sometimes treatable with drugs.
Women who are pregnant or who are planning for pregnancy must avoid contact with
potentially contaminated soil (garden or flower beds), sandboxes or cat litter boxes. If
contact is unavoidable, she should wear gloves while handling them, then wash hands
thoroughly with soap and water. The pregnant woman must also avoid raw or undercooked meat
and unpasteurized dairy products. If there are any household cats they should be kept from
access to birds, rodents, uncooked meat or unpasteurized dairy products to prevent
infection or reinfection.
1 By Janet DeLaOliva, Val Kimbark, Jessica Morris, and Margaret Shady,
Blue Ridge Community College Veterinary Technology Program Class of 1997
2 By Larry Asher, Juanita Good, and Kim Hager, Blue Ridge Community
College Veterinary Technology Program Class of 1998
3 By Christy Coe, Michelle Kirkpatrick, and Jenny Wright, Blue Ridge
Community College Veterinary Technology Program Class of 1998
