fungal | viral | bacterial
| parasites | cat bites
Introduction: Zoonotic diseases are
illnesses that can be shared between a pet and a human. There is only a very
slim chance of contracting an illness from a cat. Most people get contagious
diseases from other people, not their pets. Disease transmission may be more of
a problem for people that are very young, very old, or have illnesses that
suppress their immune system. Many of these diseases are not transmitted from
the cat to the person, but spread because the cat and person share the same
activities and environment, putting them both at risk from the organisms
Transmission: Zoonotic diseases are
spread from cats to people via several routes. Contact with the cat and sharing
the catís environment are the two most common means of exposure to potential
disease. Infectious agents can be in the catís saliva, feces, and urine and on
the catís skin and hair coat.
Treatment: Most zoonotic diseases can
be treated with specific therapy appropriate for each individual disease. Some
are not treatable.
Prevention: Common sense and good
hygiene can prevent most disease transmission between cats and people. Cat bites
should be thoroughly washed with soap and water and seen by a physician. Cat
feces should be disposed of daily. Illnesses in the cat should be treated
immediately. Cats should be kept free of internal and external parasites. Hands
should be washed after handling the cat or cleaning up its urine or feces.
Children should be taught to keep their hands out of their mouths and to wash
their hands before eating.
The following zoonotic diseases are broken down into five major categories:
fungal, viral, bacterial, internal or external parasites, and other. Specific
diseases and organisms are discussed under each major category.
Disease Description/Causative Agent: The term dermatophytosis refers to
infections of the hair, claws, and skin caused by unique fungi that have
adapted to living on animals. In humans, the infection is commonly known as
ringworm, due to the typically raised and circular shape of the lesion on the
skin. There is no worm involved. Ringworm is caused by several species of
fungal organisms. The most common species in cats are in the genera Microsporum
Signs in Cats: Signs in cats can vary tremendously. Some animals show no
disease signs, while others have patches of hair loss and scaling. Few animals
show the classic ring with central healing and peripheral crusting. Cats may
or may not suffer from itching. Some cats develop secondary bacterial skin
Signs in People: People tend to develop
skin lesions in distinct, raised circular patterns. The periphery of the
circle may have redness, crusting, and scaling. The ring gets larger as the
disease progresses. The number of rings can vary.
Transmission: Cats contact the ringworm organisms in several ways. They
can get the fungi directly from the soil or from other animals, including
other cats, dogs, and rodents. Humans can even spread the infection to their
pets. Cats can also be exposed to the infectious agents found on environmental
surfaces, such as brushes and bedding. Similarly, ringworm in people is
transmitted by contact with fungi found in the soil or by exposure to ringworm
infected animals and contaminated objects such as hair, skin flakes, bedding,
brushes, and cages.
Diagnosis: An exact diagnosis in cats and people is made by skin scrapings
and fungal cultures.
Treatment: There are a variety of anti-fungal creams, lotions, shampoos,
and oral medications available for both cats and people.
Prevention: Keep the catís skin healthy. Do not allow the catís skin
to remain damp and dirty because these conditions encourage fungal growth.
Routine brushing will help identify skin lesions early. Follow a veterinarianís
instructions when treating ringworm. If ringworm is identified on the cat, all
bedding, combs, brushes, and cages must be thoroughly cleaned and disinfected
using a mixture of 1 part bleach to 10 parts water. The fungal spores remain
viable for up to 18 months, so remove as many as possible by vacuuming floors,
walls, all surfaces, and vents. Steam cleaning carpets may help. (See F770 for more details on fungal infections in cats.)
Human Health Risk and Zoonotic Importance: Most zoonotic transmission to
humans is from cats. Humans that contract ringworm from a cat will typically
find the lesions on points of the body that contact the animal. This means
that the forearms and chest are often involved.
Disease Description: There are thousands of species of fungi in the
environment. A few of these can cause disease in man and animals. These diseases
are called mycoses. Ringworm, a superficial fungal infection, is discussed
previously. Systemic mycoses are those fungal infections that can invade
internal organs and potentially cause serious illness. These types of infections
are usually not contagious from cats to people. They occur in both species
because both people and cats share the same environment and are exposed to the
fungi living in the soil or vegetation. If a cat becomes sick with systemic
fungi, people are also at risk of infection from the organism in the
Causative Agent: The four major systemic mycotic agents are Blastomyces
dermatitidis, Coccidioides immitis, Histoplasma capsulatum, and
Cryptococcus neoformans. These organisms can live in the soil or decaying
vegetation and are typically found in areas of the country that fit the needs of
the specific organism. Coccidioides is found primarily in the sandy, dry
areas of the southwestern United States. Blastomyces thrives in sandy
soil near water and is found the Mid-Atlantic States in an area that includes
the Mississippi, Missouri, Ohio, and St. Lawrence River Valleys. Histoplasma
likes moist, humid areas and is found in soil rich with nitrogen from bat and
bird droppings. It is usually found in the center of the country throughout the
Ohio, Missouri, and Mississippi River Valleys. Cryptococcus can be found
throughout the country and is frequently associated with the droppings in pigeon
Signs in Cats: Systemic mycoses are rare,
even in areas where the fungi are concentrated in the soil and organic debris.
Many animals carry the organisms without signs of disease. Cats that are exposed
to large numbers of infective organisms or have a suppressed immune system may
become ill. Those that get blastomycosis, coccidiomycosis, or histoplasmosis may
show loss of appetite, weight loss, fever, coughing, difficulty breathing, eye
problems, lameness, and skin disease. Cryptococcosis usually causes disease of
the nasal cavity, sinuses, nervous system, eyes, and skin in cats.
Signs in People: The systemic mycoses
produce similar signs in people as in cats. The signs can be limited to the
respiratory tract and include coughing, difficulty breathing, and fever. These
mycotic agents can spread to other organs and cause a loss of appetite and
weight loss. Cryptococcosis in humans is also associated with nervous system
disease, including encephalitis and meningitis.
Transmission: Cats and people usually
contract these mycoses by inhaling infectious particles from the environment.
Diagnosis: Diagnosis in both cats and
humans is based on a history that includes exposure to fungal contaminated
areas. Diagnosis in cats is usually made by finding the organisms in a tissue
sample. This can be done by biopsy or by examination of fluid or cells
microscopically. Blood tests are often used in humans to make the diagnosis but
are used less frequently in veterinary medicine.
Treatment: Both cats and humans are treated with antifungal
medications. Treatment can take months.
Prevention: The only way to prevent mycoses is to avoid exposure to the
fungi that cause disease. This can only be accomplished by avoiding places that
contain large numbers of organisms. Certain activities, including farming,
gardening, recreational hobbies involving water, cave exploring, and cleaning
out bird/bat roosting areas, increase exposure to these fungi.
Zoonotic Importance and Human Health Risk: Most
people that are exposed to these mycotic organisms do not get ill. The human
health risk is greatest in those that have suppression of the immune system. In
addition, laboratory and hospital workers have greater exposure and greater risk
than the general public. Cat to person transmission is almost nonexistent,
except for veterinary personnel exposed to contaminated wounds and the few
reported cases of transmission by bite. The most important human health
consideration is the knowledge that cats and humans share environmental exposure
to these disease-causing organisms. If a cat contracts a systemic mycosis, it is
a warning to those that share its environment.
Sporotrichosis (Sporothrix schenckii):
Disease Description: Rabies is the
most important viral disease that is shared by humans and cats. Ninety percent
of all rabies cases are found in wild mammals, including foxes, raccoons,
skunks, and bats. Feral cats and dogs are also potential carriers, although
there have been very few reported cases. If an unvaccinated cat contracts rabies
from a wild or feral animal, the cat can potentially spread the disease to human
Causative Agent: Rabies is caused by a
virus that can infect all warm-blooded animals.
Signs in Cats: Rabies virus
attacks the nervous system, resulting in inflammation of the spinal cord and
brain. Affected animals may show no signs for several weeks after the infection.
Sick animals show varying degrees of dementia, and signs can vary from extreme
depression and quietness to "furious" behavior. The signs can include
hiding, loss of appetite, unprovoked aggression, and biting at both living and
inanimate objects. As the disease progresses, the animals become paralyzed, lose
the ability to swallow, and may have seizures. The animals die within several
days of the onset of these symptoms.
Signs in People: The symptoms vary
depending on where the virus enters the body but involve abnormalities of the
nervous system. Once the virus enters the spinal cord, the victim suffers from
paralysis, which ultimately leads to death by preventing respiration.
Transmission: The primary means of transmission is through a bite from an
infected animal. The saliva of an infected animal carries large numbers of the
viral agent. Other less common means of transmission include infected saliva
coming in contact with an open wound or abrasion. There have been a few cases of
disease being spread by the inhalation of aerosolized virus. The most common way
for the zoonotic transmission of rabies from cats to humans is through a bite
from an infected cat.
Diagnosis: The only 100% accurate
method for diagnosing rabies is to have a diagnostic laboratory perform tests on
the brain of a suspected animal. There is no perfect diagnostic test for
identifying rabies in humans. If a cat bites a person, the decision to treat the
person for rabies is made by examining the circumstances surrounding the bite
and the rabies vaccination history of the biting cat.
Treatment: There is no specific
treatment for rabies once disease signs are evident. Most cases in animals and
people are fatal once the virus replicates and enters the nervous system.
Treatment in people is aimed at vaccinating exposed people before the virus
replicates and before symptoms begin. All circumstances surrounding a cat bite
must be examined to decide on a proper course of treatment and vaccinations. In
general, if there is any possibility that the biting cat may carry rabies, the
person involved must undergo a series of preventive injections. If the cat has a
current rabies vaccination and can be found and quarantined, the injections may
be avoided. If the cat is a stray, has no record of current vaccination, or
cannot be found, the vaccines are given.
Prevention: Avoid contact with wild
animals. Maintain current rabies vaccination for all pets in the family. See
page A905 for specific vaccination recommendations. Keep cats away from wild and
feral animals. Avoid cat bites and stray or loose animals. If an owned,
vaccinated cat is bitten by another animal, wear gloves when washing the wound
and seek veterinary care for the cat. The cat may need a rabies booster and to
be quarantined. Unvaccinated animals exposed to rabies may need to be euthanized.
Decisions regarding the handling of potentially exposed cats are usually made by
local and state authorities.
Zoonotic Importance and Human
Health Risk: Although most cases of rabies are found in wild animals, wild
animals do interact with pet cats, which in turn interact with people.
Behavioral changes in rabid wild-life actually increase their interactions with
pet cats. Sick, inactive, wild animals are easy prey to cats and aggressive,
rabid, wild animals lose their normal behavioral inhibitions and may attack
cats. If these cats are not vaccinated, they can then contract rabies and expose
their owners to infection. Vaccinating all pet cats maintains a protective
barrier between people and wildlife and helps reduce the possibility of a pet
spreading rabies if it is bitten. For additional information on rabies in cats,
refer to page F702.
There are very few cases of rabies in people in the United States, but the
disease carries a high human health risk because it is invariably fatal once it
enters the nervous system.
Cat Scratch Fever:
Disease Description/Causative Agent: This
uncommon problem is caused by the bacterium Bartonella henselae that
infects human skin after a cat scratch or bite. It is most common in youth under
the age of 17.
Signs in Cats: The cats that carry this disease usually do not act sick
and do not have any signs of disease. If signs do occur, the cat may have a
fever, anemia, and neurological problems. Once infected, cats may carry the
bacteria in their blood for many months.
Signs in People: Most often, a small skin lesion that looks like an
insect bite develops at the site of a cat scratch or a bite. A few weeks later,
swollen and sometimes painful lymph nodes occur, and the person may have a
fever. The problems usually resolve on their own, and treatment is not usually
required unless the person has a compromised immune system (people with AIDS or
receiving chemotherapy). The lymph nodes may take months, however, before they
return to normal. In more complicated cases, the person may feel like they have
the flu and experience nausea, chills, weakness, loss of appetite, a headache,
and occasionally pneumonia. Reports indicate that severe inflammation of the
liver, brain, and tonsils can occur in some isolated cases.
Transmission: Cats can pick up B. henselae from flea bites. Fleas
have been shown to transmit B. henselae from cat to cat. Humans usually
become infected through a scratch or bite wound. There is also some evidence
that the bacteria are present in the environment and can be spread to humans
without the cat bite or scratch.
Diagnosis: Currently, there is no reliable test to determine if a cat is
infected with B. henselae. Many studies also show that the infection in
the cat may come and go. Because of these reasons, it is not recommended that a
cat associated with the disease be euthanized.
Treatment: Treatment for B. henselae infection is often not
necessary or beneficial in both cats and humans. If treatment is justified,
antibiotics are commonly used.
Prevention: Cat bites should be avoided by taking measures to prevent the
interactions that lead to bites. If a bite or scratch does occur, it should be
vigorously cleaned with copious amounts of water and soap and then rinsed
thoroughly. A physician should see all bite victims. The wound should be
irrigated to flush out contaminants. Any cat suspected of carrying B.
henselae should be isolated from any sick or immunocompromised individuals.
Human Health Risk and Zoonotic Importance: Most transmission to humans is
from cat bites or scratches; however, some people have been infected without a
history of being exposed to cats.
Internal and External Parasites (Toxoplasmosis,
Giardia, worms, ticks, fleas, and mites)
Disease Description: Because toxoplasmosis is transmissible to humans,
anyone who has contact with cats or cat feces should wear rubber gloves and
take caution to not contaminate benches, tables, or countertops. Humans become
infected with toxoplasmosis when they eat undercooked meat or accidentally
ingest cat feces contaminated with parasite eggs. A human can be infected with
toxoplasmosis for a period of time and not show any symptoms. Women who are
considering pregnancy and think they may have come in contact with
toxoplasmosis in the past, should see their physician before becoming
pregnant. This disease can cause miscarriage, stillbirth, and serious birth
defects in a human fetus. Pregnant women should avoid handling any cat feces
or cat litter. All litter boxes should be changed on a daily basis. See page
F836 for additional details on this disease in cats.
Disease Description: Giardiasis is the most common intestinal parasitic
disease in humans in the United States. The organisms live in the intestinal
tract of many different species of wild and domestic animals.
Causative Agent: The protozoa Giardia lamblia causes Giardiasis. Protozoans
are one-celled organisms. Most are free-living; only a few types of protozoa
live in the bodies of mammals and can cause disease.
Signs in Cats: Many cats infected with Giardia show no signs of
illness. Others may have diarrhea. The diarrhea is characterized as pale, soft,
voluminous, and especially rancid in odor. The diarrhea may be acute and
short-lived, intermittent, or chronic. Animals may lose weight despite a good
Signs in People: As in cats, Giardia infection in humans may cause no
signs, intermittent signs, or severe disease. Diarrhea, stomach pain, nausea,
gas, lethargy, and weight loss have been observed in symptomatic people.
Transmission: Waterborne transmission is the most common. The parasite forms
infective cysts that are passed in feces and make their way into fresh water
supplies. Aquatic rodents may be responsible for fecal contamination of surface
water sources. If water treatment and filtration is inadequate, the organism can
enter the drinking water and be spread to thousands of people. Contamination of
fresh water sources is also a problem for campers, hikers, and others that use
water for recreational purposes.
Direct oral-fecal contamination is a much less common means of transmission.
Cysts passed in the feces can contaminate foods and be inadvertently swallowed.
Diagnosis: This infection can be diagnosed in both humans and cats by
performing specific laboratory tests on feces or finding the parasites during
microscopic examination of the feces. Other diagnostic procedures include
intestinal endoscopy accompanied by aspiration and biopsy.
Treatment: There are no medications specifically approved and licensed to
kill Giardia. The medications that are used in both cats and humans
include specific anthelmintics and antibiotics. Treatments may not be 100%
successful and often need to be repeated.
Prevention: Proper filtration of human water sources is the most important
tool for prevention. Avoid drinking water directly from lakes, ponds, and
streams. Adults and children should be taught to wash their hands before eating.
Cats with giardiasis should be rapidly diagnosed and treated to decrease the
shedding of cysts. Proper sanitation should be practiced. Feces should be
removed on a continual basis and hands should be washed after handling cats or
Zoonotic Importance and Human Health Risk: Giardiasis is the most common
intestinal disease in the United States. It is estimated that 7% of the worldís
population carry Giardia. Although both cats and humans can have
giardiasis, cats are not at this time considered a source of infection for
people. Instead, cats are a signal that Giardia can be found in the
environment. Cats and humans often share water sources, and this water may be
contaminated with Giardia. So, if a cat has giardiasis, people may also
be at risk.
Disease Description: Intestinal worms mature and reproduce in cats.
The adult female worms lay millions of eggs that are passed in the animalís
feces and contaminate the environment. If a person accidentally ingests the
eggs, they will hatch in the small intestine and then migrate throughout the
body, causing damage to the organs they pass through. This syndrome is called
Causative Agents: Although other worms can cause this illness, the most
common cause of larva migrans from cats is ascarids, commonly called roundworms.
Signs in Cats: Signs of intestinal worms in cats can vary depending on the
age and severity of infestation. Cats may have diarrhea, vomiting, a bloated
belly, and appear unthrifty. Adult worms may be passed in vomitus or feces. Many
adult cats have no symptoms. All kittens should be assumed to have roundworms
even if the mother has been previously de-wormed and no signs of illness are
Signs in People: The signs in people vary depending on the location of the
migrating worm. Visceral larva migrans occurs when the larvae enter body organs
and is characterized by fever, high white blood cell counts, and wheezing.
Ocular larva migrans occurs when the larvae enter the eye and can result in
inflammation of the eye and loss of vision.
Transmission: There is no direct animal to person spread of this illness.
The worms and eggs are not transferred by touching and petting cats.
Transmission occurs when people accidentally swallow eggs. Mature worms in the
cat lay millions of eggs that are passed in the feces and contaminate the
environment. Humans touching the ground or soil that contains these eggs can
then touch their mouths and swallow the eggs. This occurs primarily in children
that pick up and eat contaminated dirt. Most cases occur in children because of
eating dirt and lack of personal hygiene. Adults and children that handle the
catís litter and bedding can also accidentally ingest the eggs. Cats usually
become infected when they consume the tissues of animals (rodents) that are
infected with roundworm larvae or when they ingest the infective eggs directly.
Diagnosis: The diagnosis of roundworms in cats is made by checking the feces
of the cat for roundworm eggs. Diagnosis in people is made by blood sample
Treatment: Roundworms in cats can be treated with proper use of medication
that kills the worms. See page A622 for more information on internal parasite
control. Humans are also treated with appropriate medication.
Prevention: Proper hygiene and veterinary care are the keys to preventing
worm infestations in both humans and cats. Clean up cat feces on a daily basis
to prevent egg contamination of the ground. Avoid allowing the cat to defecate
in playgrounds and school yards. If this occurs, clean up the feces immediately.
Keep children away from areas that may be heavily contaminated with eggs, such
as cat litter. Adults and children should wash their hands with soap and water
after handling cats and before eating. Adult cats should be routinely tested and
treated for intestinal worms. All newborn animals should be assumed to have
roundworms and treated following the veterinarianís guidelines.
Human Health Risk and Zoonotic Importance: There are several thousand
suspected cases of larva migrans each year. The risk is greatest in young
children. Unrecognized or treated incorrectly, larva migrans can lead to severe
illnesses and even blindness.
Disease Description: Hookworms are another intestinal parasite of cats that
can cause disease in humans if larvae are accidentally ingested or stepped on in
the soil. The larva can penetrate the skin and cause a disease known as
cutaneous larva migrans. If the larvae penetrate deeper tissues, a visceral
larva migrans syndrome can result.
Causative Agent: Ancylostoma is the common intestinal hookworm in
cats. It lives in the digestive tract and its eggs are shed in the catís
Signs in Cats: Cats with hookworm disease can have intestinal symptoms of
diarrhea and suffer from anemia. The disease can vary in severity from
asymptomatic infection to rapid death due to blood loss, depending on the number
of worms and age or condition of the cat. Kittens usually show the most severe
Signs in People: Cutaneous larva migrans is also called creeping eruption
because it is characterized by a progressive, linear, intensely itchy eruption
of the skin. The migrating hookworm larvae create the linear path. If the larvae
migrate deeper and penetrate body organs, signs of intestinal problems and other
organ disease can occur.
Transmission: Most people contact the
hookworm larva when working or walking in areas of heavy hookworm egg
concentration. The larvae directly penetrate the skin. Many cases have been
traced to the soft, wet sand at beaches and under buildings. Cats usually become
infected when they consume the larvae directly or when the larvae penetrate the
Diagnosis: Hookworm infestation in cats can be identified by examination of
fecal samples by a veterinarian. Disease symptoms and laboratory tests can
identify infection in humans.
Treatment/Prevention: Control hookworm
infestation in cats with routine testing and anthelmintic use. (See page A622
for information on internal parasite control.) Remove cat feces on a daily
basis. Wash hands after handling cats and cleaning up their feces. Teach
children to keep their hands out of their mouths and to wash their hands before
eating. Wear shoes in areas contaminated by hookworm eggs. Keep children away
from areas potentially contaminated with eggs, such as any cat litter. People
are also treated with medication that kills the parasite.
Human Health Risk and Zoonotic Importance: This
syndrome is not reported to health authorities in the United States, so the
number of annual cases is not known. However, the cutaneous larva migrans
syndrome is most often diagnosed in the southeastern and Gulf states. Plumbers
and workers that crawl beneath raised buildings, people that frequent the beach,
and children are most commonly infected.
Disease Description: Fleas can cause disease by several mechanisms in cats.
A severe flea infestation can lead to anemia from blood loss. Cats that are
allergic to flea saliva can also suffer from fleabite hypersensitivity and
allergic dermatitis. Fleas can carry the bacteria (Yersinia pestis)
responsible for the plague and are intermediate hosts for tapeworms, which are
spread to the host animal when an infected flea is swallowed.
Causative Agent: Fleas are wingless insects that feed on the blood of
animals, including cats and people. Adult fleas stay on the host.
Signs in Cats: Biting fleas can cause a wide range of signs in cats. Some
cats with only a few fleas show no symptoms. Most cats infested with fleas show
intense itching. Affected cats may lick, scratch, chew and bite at their skin.
Fleas are often concentrated along the back, above the tail and down the back of
the rear legs, so biting may be confined to these areas. Discoloration of the
hair coat and loss of hair may accompany intense biting and licking. Cats with
fleabite hypersensitivity can be extremely itchy all over their body for many
days after exposure to fleas. Cats may also show excess grooming behavior.
Signs in People: People that are bitten by fleas usually have red,
irritated, itchy, bumpy lesions on the ankles, and lower legs. The wrists and
arms may also be involved. People that are allergic to flea saliva may have
intense itchy reactions that can last for days.
Transmission: Adult fleas tend to stay on the host animal unless the flea
population on the cat exceeds several hundred, in which case the adult may leave
if it finds another host with a lower population. Most flea infestations occur
when newly hatched fleas leave the environment for a host that walks or sits
near them. Adult fleas can survive for weeks waiting for a mammalian host. Fleas
that bite animals prefer animals to people. Humans are usually bitten only when
the flea burden on the pet becomes overwhelming or when the pet is absent. Many
bites occur when people leave a house unattended for several weeks. When they
return, the hungry fleas that had been left behind bite everyone.
Diagnosis: When examining cats, the history and location of the skin lesions
are considered important in a presumptive diagnosis of flea infestation.
Identification of tapeworm segments also supports the diagnosis. An exact
diagnosis is based on observation of the flea eggs, feces, or adult parasites.
Diagnosis in people is based on the type and location of lesions, evidence of
fleas on the pet or in the house, and resolution of lesions following removal of
the biting insects.
Treatment: There are a myriad of flea control medications designed to rid
the cat and the environment of biting fleas, eggs, and larvae. (See F770
for specific details on treating fleas in pets.)
Treatment in humans typically includes removal of fleas from the environment and
topical anti-inflammatory drugs to control itching as the bites heal.
Flea control in the environment and on the cat and other pets is paramount. Flea
control can be modified to meet the needs of the cat owner and can include a
variety of topical and environmental treatments. Monthly spot-on solutions that
kill fleas meet the needs of most cat owners. Cats with tapeworm infestations
should be treated with the appropriate anthelmintics as well as being examined
and treated for fleas.
Zoonotic Importance and Human Health Risk: In most situations, fleas do not
bite humans unless the flea population is too high for the pet to adequately
support. Most fleabites on humans heal in several days and the bites will stop
once the flea population is adequately controlled. Fleas do carry the bacteria
responsible for the plague, and cats can be infected with the bacteria from
fleabites or by eating infected rodents. These cats can then pass the illness to
their owners through scratches/bites or, more commonly, by bringing the fleas
carrying plague into contact with their owners. It is also theoretically
possible, though very uncommon, for a person to swallow a flea and develop
tapeworm infection. Human health risk from exposure to fleas from cats is
primarily that of fleabites. (See F770 for specific details on flea
infestation in cats.)
Mites (Cheyletiellosis and Notoedric mange):
Disease Description: Cheyletiellosis is a disease caused by mites commonly
found on cats. Cheyletiellosis can also affect dogs, rabbits, and humans.
Notoedric mange is another disease caused by a mite that can be found on cats,
dogs, rabbits, and humans. Both cheyletiellosis and notoedric mange are very
Causative Agents: Cheyletiella blakei is responsible for
cheyletiellosis. Cheyletiella blakei is a rather large mite that lives
its lifespan on the surface of the animal it has infected, without burrowing
into the skin like other species of mites tend to do. Notoedres cati is
the mite that causes notoedric mange in cats. Notoedres cati is a
sarcoptic mite causing a skin disease in cats similar to sarcoptic mange in
Signs in Cats: Cheyletiella blakei tends to cause flaking and
dandruff on the back of cats. As the mites move, the large flakes of dandruff
will move around as well. Because this movement is visible to the naked eye, the
term "walking dandruff" is used. Itching can be severe to completely
absent. Scaling (dandruff) is very common in cats with cheyletiellosis.
Notoedric mange usually starts with itchiness and scratching at the head, ears,
and neck, with crust formation. Later, the disease may spread to other areas of
the body, especially the legs and the groin area. Secondary damage to the skin
from the catís own scratching often leads to secondary bacterial or fungal
infections. Lymph nodes may be swollen and tender.
Signs in People: Both Cheyletiella blakei and Notoedric cati
can cause intense itchiness in the people that become infected secondarily. Most
commonly, the human infection is self-limiting and goes away on its own after
several days. However, treatment may be sought through a physician because of
the temporary intense itching suffered by some people. Allergic reactions to the
mite bites may also occur in people.
Transmission: Cats become infected with the mites when they come in contact
with the parasite in the environment (carpets, rugs, bedding, etc.) or when they
are in direct contact with other infected animals. People usually become
infected when they directly contact an infected cat. Continual transmission may
occur from the infected cat to a person if the cat is not properly treated. In
such situations, the secondary infection in a person may never go away on its
own until the cat receives appropriate treatment.
Diagnosis: Diagnosis of cheyletiellosis is made by directly observing the
mites and/or their eggs. Mites and eggs may be collected from an infected
individual by skin scrapings, tape preparations, combings, vacuum techniques, or
analysis of the feces. Diagnosis of notoedric mange is also made with skin
scrapings, biopsy, and histopathology.
Treatment: Treatment of cheyletiellosis may include weekly lime sulfur dips
for 3-6 weeks, oral ivermectin treatments weekly for 4-6 weeks, or
subcutaneously injected ivermectin every 2 weeks for 3 treatments. Many
medications used to control fleas may also be successful at treating Cheyletiella
blakei infections. Because this mite can live off of the host for a longer
period than most mites, maintaining a clean environment is very important in
successful management of this type of mange. Frequent vacuuming of carpets and
rugs, washing of the bedding, and treatment of all dogs and cats in contact with
an infected pet are all important in helping to prevent re-infection of treated
animals. Treatment of notoedric mange in cats begins with clipping and cleaning
of the affected areas. Lime sulfur dips given once weekly until the skin is back
to normal can be used to cure this infection. Two or three ivermectin injections
can also be used to treat this infection. Revolution is labeled for use in dogs
to treat sarcoptic mange and may be used in cats as well; however, it is not
specifically labeled for use in treating notoedric mange in cats and its use
would be considered extra-label. Treatment of all cats on the same premises is
critical in preventing this disease from recurring. A variety of antiparasitic,
anti-inflammatory, and antibiotic creams, ointments, and oral medications may be
used to treat both types of mite infections in people.
Prevention: Maintaining good skin health in pet cats is the best prevention
available. Restricting outside access where the cat may come into contact with
stray or feral cats or other animals is also beneficial.
Human Health Risk and Zoonotic Importance: Cheyletiellosis and notoedric
mange in people are sporadic and uncommon. They are usually not considered
dangerous or life-threatening in people. However, they are important in light of
the potential irritation and annoyance they may cause for cat owners. (For
additional details on mites in pets, see F770.)
Disease Description: There are thousands
of cat bites per year in the United States. Most bites are not severe, but
depending on the location of the bite and the severity of the wound, bites can
result in infection, loss of use of a limb, disfigurement, damage to bones and
soft tissues, and death. Cat bites and scratches can also spread Yersinia
pestis the bacterium that causes plague.
Causative Agent: The damage inflicted by cat bites is a function of both
the physical trauma associated with the wound and the bacteria that spread from
the catís mouth into the wound. Catsí mouths contain many species of
bacteria; several of these bacteria can cause disease if inoculated into a
wound. One common isolate of infected cat bites is Pasteurella multocida,
a bacteria that can cause infection.
Signs in People: Most bites from familiar cats occur on the arms, hands,
and possibly the legs. Most facial bites are inflicted on children. The majority
of cat bites result in small wounds with minimal bruising, bleeding, and tissue
damage. However, severe injury can result depending on the location and type of
wounds inflicted. Physical damage results from injury to the soft tissue and
bony structures involved in the bite. Additional signs will result if infection
occurs secondary to transmission of bacteria from the catís mouth. Signs of
infection can include pain, swelling, redness, and drainage from the wound.
Septic arthritis, abscesses, and even fatal systemic infections can occur if
treatment is not begun promptly.
Transmission: Cat bites are not a traditional zoonotic disease. There is
no passive spread of a contagious agent from cat to person. Instead, disease
spread is the result of an improper physical interaction between a person and a
cat. Aside from people that handle cats routinely, such as veterinarians, most
bites occur in children under the age of 12.
Diagnosis: Diagnosis is based on the report of the victim and observation
of the wounds.
Treatment: All bites should be vigorously cleaned with copious amounts of
water and soap and then rinsed thoroughly. A physician should see all bite
victims. Irrigation should be performed to flush out contaminants. Removing
severely damaged or contaminated tissue (debridement), suturing, and/or referral
to a specialist may be needed. Many people are treated with antibiotics to
prevent infection. Surgery may be required depending on the severity of the
Prevention: Cat bites can be avoided by taking measures to prevent the
interactions that lead to bites. The vast majority of bites are inflicted by
family pets or animals that are known to the victims. Education and owner
responsibility are the keys to the prevention of bites. Owners should learn
proper methods for handling cats and behavior modification techniques. Children
should be taught to avoid loose animals, how to properly handle and interact
with all cats, and the necessary safety tips to avoid bites. Young children
should always be supervised when playing with animals; no child should ever be
alone with a dog or cat. Aggressive behaviors in a family pet should be
identified and modified with appropriate therapy and training.
Zoonotic Importance and Human Health Risk: Every year there are thousands
of dog and cat bites in the United States and 10 to 20 fatalities. Most bites
involve children. Bite victims can suffer from long term negative physical and