For Pet \ Owners
Pet Cats & Human Health
As of 2000, there were estimated to be approximately 4.5 million
domestic cats in Canadian homes. Many cat owners live in very
close contact with their feline companions. It is common for house
cats to have access to areas like the kitchen counter where food is
prepared, and many cats sleep in the same bed as their owners.
Given the high frequency of very close contact between cats and
people, it is easy to see how infection could be transmitted
between them. Overall the risk of zoonotic disease transmission
from cats is very low, nonetheless it is important to be aware that it
exists, and to take some simple precautions to reduce this risk. Things to Think About Before Getting a Cat
Your veterinarian is a great source of information and advice about the time and financial commitments involved in
owning a cat what kind of cat would be best suited for you and from where you should get one. In order to decrease
the risk of your cat becoming sick and/or transmitting infection to a person, it is recommended that the cat should be: Well socialized and accustomed to handling:
this will make the cat less likely to bite or scratch a person. Examined regularly by a veterinarian:
in order to assess the overall health of the cat, check for external and
internal parasites, and clip the cat’s claws. Declawing the cat is NOT necessary. Spayed/neutered:
this will help to decrease fighting with other cats and the tendency to roam, as well as the
tendency for male cats to urine mark, and it eliminates the possibility of pregnancy in female cats. Kept indoors:
to decrease the chances of the cat becoming infected with worms, fleas or bacteria; bringing
rodents or birds back into the house; or becoming sick or injured due to contact with other cats or wildlife.
If your new cat will be in contact someone who may be more susceptible to infectious disease (e.g. young children;
immunocompromised HIV/AIDS, transplant and cancer patients), it is also recommended that your cat should be: At least one year old:
this decreases the likelihood that the cat will have intestinal parasites, and makes it
easier to judge the cat’s overall temperament to ensure it is relatively friendly and docile. Examined thoroughly by a veterinarian PRIOR to being taken home:
The cat can be kept in isolation at a
clinic or at another house for a short time if treatment for a particular condition is necessary. Already litter trained:
to ensure that stool and urine (and the pathogens in them) are not spread in the house. Not acquired from a shelter:
because such cats usually have an unknown medical history and may be in
contact with other sick animals at the shelter facility, even if they do not appear sick themselves. Cat Care Tips Feeding
Cats should NOT be fed raw meat or eggs, or commercial diets with raw ingredients.
Uncooked meat is often contaminated with pathogens such as Escherichia coli
sp. or Toxoplasma
, which can infect the person preparing the food for the
cat. There is also potential for these pathogens to infect the cat, which may or may not
make the cat sick, but will result in the cat spreading them around the house.
Feeding a high-quality, balanced commercial cat food will provide your cat with all the
nutrients it needs, and help it to stay healthy and fight off disease. Litter Box Cleaning
If you have more than one cat, you should have the same number of litter boxes plus one available for them.
The frequency with which a litter box must be cleaned depends in part on how often the cat uses it. In general,
stool and litter clumps (if clumping litter is used) should be scooped out once a day to once a week.
Litter boxes should be completely emptied, cleaned with scalding water, disinfected and dried approximately once
a month. It is important that all visible dust and debris is cleaned out of the box prior to applying a disinfectant
such as concentrated household bleach. The disinfectant should be left in contact for
at least 10 minutes, then the litter box should be thoroughly rinsed with water and
refilled with clean litter. Never clean a litter box in the kitchen sink.
It is important to thoroughly wash your hands with soap and running water after scooping
out or cleaning a cat’s litter box. The risk of becoming sick from a pathogen from a cat’s
stool is minimal in most people, but it is higher for young children, immunocompromised
individuals and pregnant women. If possible, these higher-risk individuals should not
handle used cat litter, and should avoid contact with cat stool in general.
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Holding a Cat
Very small kittens can be picked up by the loose skin on the back of the neck (called the
scruff), but their body should always also be supported by a hand under their rump. An
adult cat should never be picked up by its scruff. Instead, pick up the cat with one hand on
the chest under the forelegs and the other hand under the cat’s rump. Use the upper hand
to hold the cat close to your body, and the other to support the cat’s weight. Don’t put the
cat’s paws on your shoulder, as this may encourage it to try to climb up onto your shoulder
Preventing Bites and Scratches
Anticipate a cat’s behaviour in situations where it might become scared or feel
uncomfortable. Do not try to trap or hold a frightened cat if it tries to get away.
Children and immunocompromised or elderly individuals should not hold a cat in
situation with which the cat is unfamiliar, such as during veterinary appointments.
Never play with a cat using only hands or feet – always use an appropriate toy.
Always supervise children playing with a cat so they are gentle and quiet.
Do not disturb a cat that is eating, sleeping or using the litter box
Do not approach stray or unfamiliar cats, even if they seem fri
Beware of cats that may have petting-induced aggression. Vaccines and Parasite Control for Cats
Keeping your cat’s vaccines up-to-date will help keep your pet healthy, and also make it less likely to get sick from a
disease that it might be able to transmit to people. Some vaccines, such as rabies vaccine, are recommended for all
cats, while others might only be recommended in certain situations, like if your cat was going to stay at a boarding
kennel. Talk to your veterinarian about what vaccines your cat should have. Many of the vaccines only need to be
given every three years once your cat is an adult.
rry infections from animal to animal or sometimes from animals to people.
The larvae of some types of intestinal worms in cats (e.g. hookworms, roundworms) can
cause a disease called larval migrans in people, especially children. In Canada,
however, these infections are uncommon, even though the worms are very common,
particularly in kittens. Your cat and its stool should be examined for parasites at least
once a year at its annual check-up, and kittens should be dewormed when they are
vaccinated. What your veterinarian recommends for regular parasite control in an adult
cat will depend on where you live, the season, whether or not your cat (or other animals
in the house) goes outside, and whether or not there is a child or immunocompromised
person living with the cat. Infection Control Bite and Scratch Care
Bites and scratche
are much more likely to get infected than bites from
other animals. Bites in particular can be very deep which makes them hard to clean
well, and may allow infection to fester.
It is very important to wash any wound from a cat immediately and thoroughly with
soap and running water. It can then also be treated with an antiseptic. Seek medical attention
bite wound on a hand, over a joint, that goes down to
the bone or involves a crushing injury, if the wound becomes excessively red, painful
or swollen, if there is discharge, if the person develops a fever, or if the person is
immunocompromised (e.g. HIV/AIDS, transplant or cancer patient).
All bite wounds should be reported to your local public health n
u it. If the biting
animal’s rabies vaccination status is out of date or unknown, the animal needs to be
isolated for 10 days. If the cat was a stray, call animal control so it can be captured. Hand Hygiene
Hands should be washed with soap and water after handling any pet, including cats. This is especially important after
cleaning a litter box or coming in contact with urine, stool, eye or nose discharge, or a wound on a cat. This simple
precaution can reduce the transmission and spread of several of the zoonotic pathogens which are carried by cats.
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Zoonotic Diseases of Cats
The following are some of the more common and well-known diseases that cats can transmit
to people. Please refer to individual disease information sheets for additional details. It is
also important to remember that many of these pathogens may be carried by a cat without
actually making the animal sick, and may therefore go undetected. Infections that cause diarrhea:
These include the bacteria Campylobacter jejuni
sp., and the protozoa Cryptosporidium
sp. and Giardia intestinalis
. All of these are notifiable diseases in people in Canada. They may cause no illness at all, or
they may cause diarrhea, or in higher-risk individuals (e.g. HIV/AIDS, transplant, cancer patients, young children)
they may cause much more serious illness. They are transmitted by contamination of food or water that is
ingested, or fecal contamination of the hands which is transfered to the mouth.
Cat scratch disease
(bartonellosis, benign lymphoreticulosis, bacillary angiomatosis):
An infection caused by a proteobacterium, Bartonella henselae
, which infects up to 40% of cats, but does not
make cats sick. It is believed to be transmitted to people when a bite or scratch from a cat is contaminated by the
cat’s blood or flea excrement (which contains digested blood) from an infected cat. Infection often causes fever
and very swollen lymph nodes, but it can be more serious or even fatal in immunocompromised individuals.
Other cat bite wound infections:
It is estimated that 20-50% of cat bite wounds become infected. Usually multiple kinds of bacteria are present in
each wound and infection can be very severe. Cat bites can also create deep puncture wounds which may result
in infection of deeper tissues such as bones and joints. Larval migrans caused by hookworm and roundworm larvae:
This condition can be caused by various species of hookworms and roundworms, some of which infect cats. Eggs
of the parasites are passed in the feces of infected animals, and release larvae which can penetrate a person’s
skin or are accidentally ingested. The larvae then migrate under the skin (cutaenous), through various internal
organs (visceral) and occasionally the eye or brain (ocular or neurological), causing irritation and inflammation
(larval migrans). The ocular form can result in blindness. Infection is most likely to occur in young animals and
A viral infection of the nervous system which is almost always fatal once clinical signs appear. Cats are usually
infected by direct contact with a rabid animal, most often a skunk, fox, raccoon or bat. Transmission occurs when
the saliva of an infected animal comes in contact with a wound (such as a bite or scratch) or mucous membrane
(eyes, nose, mouth). Rabies is a reportable disease in humans and animals in Canada. Ringworm
A fungal skin infection caused by one of several species of Microsporum
. It usually causes no
signs in cats, but when it does it can look like almost any feline skin disease. In humans it can cause distinct areas
of red, raised, itchy skin with pale centers, which therefore look like “rings.” The fungus is transmitted by contact
with the skin, fur or dander of an infected cat, particularly if the person’s skin is damaged or moist.
An infection caused by the protozoal parasite Toxoplasma gondii
. Exposure to T. gondii
is common in people and
in cats, but clinical disease is uncommon in healthy individuals. Infection in pregnant women, however, can cause
abortion, premature delivery or still birth. Cats shed oocysts in their feces that become infective after about 24
hours, but many people are more likely to be exposed to oocysts in soil or by eating undercooked meat
Transmission from cats is likely comparatively uncommon. Recognizing Illness in Cats
The most common signs of illness in cats are lethargy and decreased appetite. A cat that is not feeling well will often
hide, and may not be easy to coax out into the open if it is not hungry. If you think your cat is sick, it should be brought
to a veterinarian as soon as possible. Just like for people, it is usually easier (and ultimately cheaper) to have your cat
examined and treated when the signs of illness are still mild, instead of waiting to “see what happens” and risk the
animal’s condition becoming more severe.
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Other signs of illness in cats
include the following:
Changes in stool colour and consistency (either harder or softer (i.e. diarrhea))
Changes in urine colour (especially if it appears to contain blood)
Inability to urinate or defecate, or excessive straining or crying in the litter box
Unkempt fur from not grooming, or excessive licking of one area of the body
Excess discharge from the eyes or nose, often accompanied by sneezing
Drinking more than usual
Vomiting more than usual,* or unproductive retching
* It is normal for many cats to occasionally vomit a hairball. Some may do so more frequently
than others depending on how much hair they swallowing when grooming.
Although it is true that a sick cat with a fever will often have a warm, dry nose, many healthy cats also have dry noses.
Furthermore, a cat can still be very sick even if its nose is cold and wet.
Zoonotic Disease Risk
The zoonotic risk to the general population posed by most domestic cats is: HEALTHY ADULTS/OLDER CHILDREN LOW RISK 6789 10 HIGH RISK 1 2 3 45
Groups at higher risk of acquiring a zoonotic disease from a cat include immunocompromised individuals (e.g.
HIV/AIDS, transplant and cancer patients), infants and young children less than five years of age, and the elderly.
There are also precautions that should be taken by pregnant women around cats in order to protect the fetus.
For these groups, the zoonotic risk posed by most domestic cats is likely: YOUNG CHILDREN/IMMUNOCOMPROMISED PERSONS LOW RISK 1 2 3 456789 10 HIGH RISK Precautions for Immunocompromised Cat Owners & Young Children
Keep the animal’s claws well trimmed. Plastic nail caps can also be applied to help prevent scratching. Declawing
a cat is unnecessarily invasive.
Have someone else clean the cat’s litter box. Otherwise wear thick rubber gloves and be very diligent about hand
washing afterwards. The litter box should also be kept away from food preparation and sleeping areas.
Keep the cat in good health by having regular examinations by a veterinarian, as well as up-to-date vaccines and
regular fecal exams to check for parasites. Ensure that the cat is free of fleas. Avoid contact with kittens.
Keep the cat indoors at all times so it does not hunt birds or rodents, or fight with other animals.
Feed a high-quality commercial cat food that does not contain any raw ingredients.
Do not let the cat lick the person in question, particularly on the face, nor should they handle the cat if it seems ill.
Always supervise young children when they play with a pet. Teach them to be gentle and quiet so the animal is
not frightened. Also teach them never to approach an animal they do not know.
Hand washing with soap and water after handling a cat or contacting any urine, feces or other bodily secretions is
one of the simplest and most important means of infectious disease control. Precautions for Pregnant Women With Cats
The risk of exposure to Toxoplasma
from a mature house cat is very small. Nonetheless, pregnant women should
avoid contact with cat stool, especially if it is more than 24 hours old.
Preferably someone else should clean the cat’s litter box. Otherwise a pregnant woman should wear thick rubber
gloves and ensure that she washes her hands thoroughly afterwards, particularly before handling food of any kind.
Cleaning the litter box daily will also help because oocysts in fresh feces at room temperature usually do not
become infective for 1-3 days.
4/4 www.wormsandgermsblog.com Updated October 23, 2008