Page 715 - Problem-Based Feline Medicine

32 – THE CAT WITH SIGNS OF ACUTE SMALL BOWEL DIARRHEA 707

Cats or kittens with clinically significant crypto- Pathogenesis
sporidiosis may be treated with tylosin, clindamycin
Giardia intestinalis is a commonly encountered flagel-
or azithromycin, however, the clinical effectiveness of
late protozoan parasite, with a direct life cycle.
these drugs is not well tested.
Giardia cysts are ingested from contaminated water,
Cats or kittens that are dehydrated and anorectic will
or directly from animal to animal (e.g. in kennels or
require supportive care in the form of fluid replace-
catteries).
ment therapy or nutritional support or both.
Excystation of the ingested cysts releases two motile
Prognosis trophozoites in the small intestine.
The prognosis for complete recovery in immunocom- Cysts are approximately 9–13 microns in size but are
petent cats and kittens is excellent. not routinely identified in flotation solutions because
they are not shed consistently and are small.
Any adult cat with coccidiosis or cryptosporidiosis
should be carefully evaluated for the presence of other Sugar flotation solutions will cause the cysts to shrivel.
immunodeficiency (e.g. FIV) or immune-compromising
Trophozoites are slightly larger, tear-drop-shaped,
diseases (e.g. neoplasia, IBD, etc.).
have four pairs of flagella and are binucleated. The
Prevention trophozoites attach to the mucosal brush border to
absorb nutrients. Little is known about encystation and
Coccidiosis is primarily a problem of poor sanitation, what triggers it.
and over-crowded, high-stress conditions that occur in
Cysts are susceptible to desiccation, but can exist for
catteries, shelters and other population-dense situations.
months in a cool, moist environment.
Because the oocysts (both Isospora and Cryptosporidia)
The pathogenesis of Giardia infection is not well
are environmentally resistant, only aggressive sanita-
understood but is believed to involve malabsorption,
tion measures (daily fecal removal, disinfection of
disturbances in brush border enzyme function and
cages, runs and food utensils with steam cleaning or 10%
possible enterotoxin production.
ammonia solutions) will prevent contamination.
Severe clinical disease is more common in young
Public health cats, but adults can become infected and symptomatic.
Protective immunity appears to protect cats from the
Cryptosporidiosis is a significant zoonosis, and thus,
development of clinical signs, but may not protect from
careful precautions must be taken in handling infected
shedding, since some animals will continue to shed
animals, their feces and their environments.
organisms despite treatment.
Even though the association between human infection
and feline cryptosporidiosis is weak, this problem
Clinical signs
should not be taken lightly, especially in cases of cats
owned by immunocompromised humans. Most adult cats infected with Giardia spp. remain
asymptomatic.
GIARDIASIS** The most common sign observed is the presence of
liquid to semiformed diarrhea, associated with
Classical signs increased frequency and quantity of defecation, in an
otherwise healthy cat.
● The most common sign is liquid, to
semiformed, diarrhea with increased Vomiting, dehydration, lethargy and anorexia may be
frequency and urgency. observed in severe cases, but are uncommon.
● Some animals are asymptomatic, and most
Occasionally, chronic small bowel diarrhea with weight
remain bright, alert and afebrile.
loss and poor body condition are observed.