This information is provided by
Provet for educational purposes only.
You should seek the advice of
your veterinarian if your pet is ill as only he or she can correctly advise
on the diagnosis and recommend the treatment that is most appropriate for
Note for Pet Owners:
Toxocara cati is a
common worm infection in cats. Humans are occasionally reported to
be infected by picking up the disease from the environment or from
handling cats. ALL cats should be routinely treated against this worm to
reduce the number in the cat population and in the environment, and so
reduce the risk of contact and transmission to humans. (See Zoonoses).
are not born with the disease but they are infected after birth
Topics on this Page:
Infection with the worm Toxocara cati is called Toxocariasis. Many cats
have the worm present in their body but they may show no external
signs of disease. However, these cats periodically pass the egg stage of the
worm in their faeces and so contaminate the environment and act as a source of
infection for spread to other animals.
CauseFeline toxocariasis is caused by a nematode - Toxocara cati
is a roundworm. These worms live in the
small intestine of cats
There are no specific breed predispositions. All cats can be infected by Toxocara
cati. Wild cats can also be infected by this parasite.
The vast majority of cats infected with T.cati show no signs of disease.
kittenss are most likely to show clinical signs, and these will be worse if the
kitten has a large number of worms.
Signs include vomiting, diarrhoea, stunted growth rate,
distended abdomen (pot-bellied appearance), pale mucus membranes (eg gums).
Sometimes infected kittenss have abdominal discomfort, groan when touched or
lifted and are reluctant to move.
Death is rare , but has been reported and
has been due to obstruction of the intestine or ulceration and
perforation of the intestine wall.
Life-CycleIt is important to understand the life-cycle of the worm so that it can be
- Worm eggs are passed in the faeces of cats infected with the worm. These
eggs are very small but can be seen by examining samples of the faeces
under a microscope.
- After a period of maturation in the environment these eggs become
infective to other animals. This period of maturation depends upon weather
conditions and environmental temperature in particular. In the UK it takes
2-3 weeks during the summer and several months during the winter. The eggs
can survive for 2 years or more in the environment.
- The infective eggs are ingested and can develop in intermediate hosts
including earth-worms, cockroaches, birds, rodents and dogs. The infective
eggs or larvae are then ingested by a cat.
- The larvae that hatch from the eggs develop into mature worms in the small intestine
and start shedding eggs after a few
Kittens can be infected after birth through milk - but they are not
infeted in the uterus.
All kittens should be assumed to be infected.
Diagnosis can be confirmed by
identifying Toxocara cati eggs in faeces samples. However it should be
remembered that eggs are not being shed into the faeces all the time, so false
negative results are possible.
The aim of treatment is to protect young kittens and they should be treated
routinely at 3 weekly intervals from 4 weeks to 16 weeks of age.
In addition regular treatment of adults is advisable to reduce
the re-infection rate. In the UK the following products are licensed for use
The prognosis is good.
Long term problems
Re-infection is a problem in dogs living in areas in which
there is high environmental contamination.