Page 707 - Problem-Based Feline Medicine

32 – THE CAT WITH SIGNS OF ACUTE SMALL BOWEL DIARRHEA 699

NEOPLASTIC
● Tumors of the small intestine* (p 715)
The most common tumor of the feline digestive system is alimentary lymphoma. Other tumors that
occur in the small intestine are adenocarcinomas (second), and mast cell tumors (third), with
fibrosarcomas, leiomyosarcomas and carcinoids occurring rarely. With the exception of lymphoma,
which can occur at any age, most tumors occur in old cats. The clinical signs most often observed
are anorexia and weight loss, with vomiting or diarrhea less common. The diarrhea is often chronic,
but the onset may be acute.
IMMUNOLOGIC

● Idiopathic inflammatory bowel disease (IBD) (p 714)
Generally considered to be a disorder associated with chronic, intermittent vomiting, diarrhea or
weight loss, but acute exacerbations of diarrhea may occur. IBD is described primarily by the pre-
dominant inflammatory cell type infiltrating the mucosa. Lymphocytic plasmacytic enteritis is the
most common form of IBD, but eosinophilic and suppurative forms of the disease occur as well.
INFECTIOUS
● Coccidiosis (isosporosis, cryptosporidiosis, toxoplasmosis)** (p 705)
Infections that result in mild to moderate diarrhea are most common in neonates and immunosup-
pressed adults. Most adults have asymptomatic infestations. The species of coccidia most com-
monly associated with disease in cats are Isospora spp., Cryptospordium parvum and occasionally
Toxoplasma gondii.
● Giardiasis** (p 707)
Acute or chronic small bowel diarrhea is the most common clinical presentation, however in some
cats large bowel diarrhea also may occur.
● Nematode parasites (roundworms, hookworms)* (p 717)
Common signs occurring in kittens with roundworms (Toxocara cati, Toxascaris leonina) include
unthriftiness, diarrhea and pot-bellied appearance, however, vomiting may also occur.
● Salmonellosis* (p 719)
Diarrhea, weight loss and systemic illness are primarily problems in young or debilitated cats, as
most cats are asymptomatic carriers. The disease is most important clinically in young kittens or
geriatric cats that develop septicemia due to Salmonella spp., and may die acutely. Salmonellosis is
a zoonotic disease.
● Clostridium perfringens enterocolitis* (p 721)
Diarrhea occurs due to sporulation of clostridial organisms and release of enterotoxin resulting in a
secretory diarrhea that is usually small bowel in character, but can also have a large bowel component.
● Feline coronavirus infections (feline enteric coronavirus/feline infectious
peritonitis* (p 718)
Feline enteric coronavirus causes mild, transient diarrhea in young kittens, and is the source of
feline infectious peritonitis virus (FIPV). Systemic infectious disease by FIPV is characterized by
vasculitis and granulomatous lesions in affected organs. Since FIPV rarely affects the GI tract sin-
gularly, vomiting is often associated with the disease effects on the liver, kidneys or other organs.
Rarely FIPV causes intestinal granulomas that obstruct the GI tract and cause vomiting or diarrhea
that is usually chronic, but may have an acute onset.

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