Page 322 - Problem-Based Feline Medicine

314 PART 6 CAT WITH WEIGHT LOSS OR CHRONIC ILLNESS

● Lactational and prenatal infections do not occur.
INTESTINAL PARASITES**
● Rodents can act as transport hosts.
● Infection can cause cutaneous larva migrans in
Classical signs
humans.
● Usually in kittens or young adult cats.
Adult tapeworms live in the small intestine and both
● Weight loss or failure to gain weight,
D. caninum and T. taeninaeformis require an interme-
usually with a good appetite.
diate host to complete their life cycle. Gravid proglot-
● Diarrhea and/or vomiting may be present.
tids containing many eggs are released from the adult
worms. They may rupture within the intestines, or
Pathogenesis remain intact and pass out in the feces and be seen
around the cat’s anus.
Intestinal parasites that can infect cats and, at least
● Dog and cat fleas are the intermediate hosts for
occasionally, cause weight loss associated with a good
D. caninum.
appetite include nematodes (large ascarid roundworms
● Rodents are the intermediate hosts for T. taeni-
Toxocara cati and Toxascaris leonina), and hook-
naeformis.
worms (Ancylostoma braziliense, A. tubaeforme
and Uncinaria stenocephala), cestodes (tapeworms Isospora spp. live in intestine of cats and shed oocysts
Dipylidium caninum and Taenia taeninaeformis), and into the environment via the feces. Sporulated oocysts
protozoans (coccidians, Isospora felis, I. rivolta, and can be directly ingested by other cats.
Cryptosporidium parvum and flagellates Giardia ● Rodents harboring cyst stages can act as transport
lamblia and Tritrichomonas foetus). hosts.
● Infection and clinical disease is seen most com-
T. cati and Isospora spp. are the most common para-
monly in cats kept in large unhygienic groups.
sites of kittens. D. caninum, T. taeninaeformis and
G. lamblia are the most common parasites of adult cats. C. parvum lives in the small intestine and sheds
oocysts that can either break open to release sporo-
Adult T. cati live in the small intestine of cats. Eggs
zoites into the intestine resulting in chronic infection or
are passed into the environment with the feces to be
be passed out into the environment where they can
ingested by other cats, in which they migrate via the
remain viable for many months.
liver and lungs to the small intestine.
● Infection can cause severe disease in immuno-defi-
● Larvae can be transmitted lactationally to kittens,
cient humans.
but prenatal infection does not occur.
● Rodents can act as transport hosts. In cats, G. lamblia lives in the jejunum and ileum.
● Infection can cause visceral larva migrans in humans. Environmentally resistant cysts are shed in feces, con-
taminate drinking water or food, and are then ingested
Adult T. leonina live in the small intestine of cats.
by other cats.
Eggs are passed into the environment with the feces to
● Infection and clinical disease are seen most com-
be ingested by other cats where they mature in the
monly in cats kept in large unhygienic groups.
wall of the small intestine.
● Giardia spp. do not appear to be host-specific and
● Lactational and prenatal infections do not occur.
have a world-wide distribution in tropical and tem-
● Rodents can act as transport hosts.
perate areas.
● Does not cause visceral larva migrans in humans.
In cats, T. foetus lives in the colon and sheds flagellated
The prevalence of hookworms varies. Ancylostoma
protozoa into the feces. Infection and clinical disease
spp. prefer warm, humid climates, while U. steno-
are seen most commonly in young cats kept in large
cephala can live in colder climates. Severe hookworm
unhygienic groups.
infections are usually seen in warm, moist climates.
● Adults hookworms live in the small intestine of
Clinical signs
cats. Eggs are passed into the environment with the
feces and then hatch. They can be ingested by other The prevalence of intestinal parasites varies with geo-
cats or infect them by skin penetration. graphic location, the level of sanitation, whether or