is feline chlamydophila disease?
chlamydophila disease refers to infection with a type of bacterium
called Chlamydophila felis. Many different strains
of chlamydia type bacteria exist. In general they are highly
species specific - ie, each strain usually infects one or
a small number of different animals. The bacterium that infects
cats, known as Chlamydophila felis, appears to be
highly adapted to the cat and rarely, if ever, causes disease
in other animals.
Chlamydophila organisms are very fragile and cannot survive
for any significant period of time in the environment. Infection
therefore occurs through direct contact between animals.
What disease does C felis cause in cats?
In cats, C felis mainly causes conjunctivitis (infection
and inflammation of the delicate membranes or conjunctiva
that cover the inner surface of the eyelids and the white
part of the eye itself, called the sclera). Clinical signs
usually develop within a few days to a week after infection
and usually begin as a watery discharge from one or both eyes.
Although sometimes only one eye is affected when signs first
develop, within a few days both eyes become involved. Due
to the discomfort, affected cats may hold their eyelids partially
closed. As the disease progresses, severe swelling and reddening
of the conjunctiva may be seen and the discharge changes from
watery to a thicker yellowish discharge. Although conjunctivitis
is the major clinical sign, there may also be mild sneezing
and nasal discharge in some affected cats. Occasionally there
is a mild fever which can result in lethargy and inappetence
but, generally, affected cats remain bright and eat well.
If left untreated, the conjunctivitis often persists for six
to eight weeks or longer and cats may continue to shed the
organism for many months.
Although mainly a cause of conjunctivitis, C felis has also been found in the lungs, gastrointestinal tract and
reproductive tract of cats and there is some speculation that
it may be a cause of infertility in breeding queens.
cats are at risk of infection?
Chlamydophila infection is relatively common in cats and up
to 30% of cases of chronic conjunctivitis may be caused by
this organism. However, because the organism does not survive
in the environment and requires direct contact between cats
to spread, disease is much more commonly seen where larger
groups of cats are kept together, such as multi-cat households,
catteries and shelters.
Although cats of all ages can be infected, disease is seen
most commonly in young kittens (5 - 12 weeks old) with persistent
or recurrent infection.
Are there other causes
Although chlamydophila infection is a common cause of conjunctivitis
in cats, many other causes of conjunctivitis exist. These
can range from trauma to the eye, the presence of ocular irritation
caused by foreign material in the eyes or hairs rubbing on
the surface of the eye, through to other infectious agents.
The cat flu viruses (herpesvirus and calicivirus) are common
causes of sneezing together with ocular and nasal discharge
in cats and they too can cause conjunctivitis. As with chlamydophila,
cat flu viruses are more common in kittens and where groups
of cats are kept together. Some cats can be infected with
both flu viruses and chlamydophila.
How is chlamydophila disease diagnosed?
Because there are other potential causes of conjunctivitis,
definitive diagnosis requires demonstration of the presence
of the organism. Swabs can be taken from the eyes of affected
cats and sent to specialist laboratories where the presence
of the organism can be identified (through culture or other
special techniques). This is usually a highly reliable way
of making a diagnosis.
What is the treatment
for affected cats?
Chlamydophila infections respond well to a number of different
antibiotics. A group of antibiotics known as tetracyclines
have generally been considered the treatment of choice for
chlamydophila in cats. Certain other antibiotics may also
be effective, but have to be chosen carefully as a number
of antibiotics are completely ineffective against the organism.
Topical therapy with eye drops or ointment is usually recommended,
but this should be combined with systemic (oral) therapy as
the organism can be present at sites other than just the eyes.
If giving eye drops is difficult, infections will still respond
well to oral therapy alone. Generally, treatment is recommended
for a period of four weeks and all cats in the household should
be treated (irrespective of whether they are showing clinical
signs). Care has to be taken treating pregnant cats and young
kittens (giving tetracyclines during development of the teeth
can lead to their discolouration) and at this time other antibiotics
may be used.
disease be prevented?
A vaccine exists to protect cats against chlamydophila conjunctivitis.
The vaccine does not always prevent infection, but is certainly
helpful in preventing severe clinical disease. Its use can
be recommended in high risk situations.
Can humans catch
infection from cats?
Humans can be infected with chlamydia but the bacterium that
infects cats, Chlamydophila felis, is highly adapted
to this species. There have been one or two reports that have
suggested human conjunctivitis has occurred following contact
with a cat harbouring C felis, but the risk appears
to be extremely low. Routine hygiene precautions are recommended
when handling and treating infected cats (washing hands after
stroking or giving medications and avoiding close face-to-face
contact until the infection has resolved).