Page 729 - Problem-Based Feline Medicine

32 – THE CAT WITH SIGNS OF ACUTE SMALL BOWEL DIARRHEA 721

The presence of the organism can be confirmed by culture
CLOSTRIDIUM PERFRINGENS
ENTEROCOLITIS* of fresh fecal specimens, however, because this is part of
the normal flora, this approach is not definitive.
Classical signs Similar to the dog, there appears to be a poor correla-
tion between the presence of fecal endospores and
● Acute small bowel diarrhea with or without
the presence of enterotoxin.
anorexia or lethargy.
Reverse passive latex agglutination (RPLA) tests for
clostridial enterotoxin are available and have been
used in dogs and humans, but have not been evaluated
Pathogenesis
in cats. In dogs, the test does not differentiate dogs
Clostridium perfringens is an anaerobic, Gram- with clostridial diarrhea from normal dogs, as > 25%
positive, spore-forming rod that is a normal inhabi- of normal dogs are positive. An enzyme immuno-
tant of the colon in animals and people. assay (Techlab, Inc., Blacksburg, VA) appears to be
more specific in dogs. A positive enterotoxin assay
Enterotoxin formation by Clostridium spp. causes
determined by ELISA (regardless of endospore num-
increased membrane permeability and results in
bers) in the context of clinical signs consistent with
fluid and ion loss. Eventually, the epithelial cells will
clostridial infection is strongly supportive of
die and slough.
clostridial-associated diarrhea.
Most clostridia exist in the GI tract in their vegeta-
PCR tests are also utilized for testing feces for entero-
tive state, but under certain conditions (alkaline envi-
toxin, but are not universally available.
ronment, other concurrent infections, antibiotic therapy
or stress) the bacterium will undergo sporulation and
Differential diagnosis
release of enterotoxin.
Following an infection, the organism can be shed for Other enteric bacterial infections, parasitic and pro-
weeks to months, and because of its stability in the tozoal infections, dietary disturbances and toxin
environment, has the potential to infect many other sus- exposure should all be ruled out first.
ceptible animals. Because this disease can occur in any age of cat, other
considerations are metabolic disease (hyperthy-
roidism), liver disease and neoplasia.
Clinical signs
The most common clinical sign is severe, watery to Treatment
mucohemorrhagic diarrhea.
In severely ill cats, parenteral fluid therapy and intro-
In most cats, the diarrhea only lasts a few days, but duction of a bland, highly digestible diet is necessary.
in some, it may persist and become chronic. Animals
The primary treatment is the use of antimicrobial
that have severe diarrhea will become dehydrated,
drugs that have a good spectrum against anaerobic
lethargic and may be anorexic.
bacteria: metronidazole, tylosin, ampicillin/amoxicillin
There is no breed, sex or age predisposition, but cats and clindamycin have all been successfully used.
from catteries or in stressed environments are at
Addition of dietary fiber (1 tbsp psyllium/cat), or
increased risk.
changing to a diet with increased dietary fiber may
greatly reduce the proliferation of clostridial organ-
Diagnosis isms in the large bowel.

The history (acute onset, predisposing conditions)
Prognosis
and physical examination findings (character of the
diarrhea) help to focus the diagnostic approach toward Good with appropriate antibiotic therapy in most
infectious, parasitic and dietary causes of diarrhea. cats.