Page 723 - Problem-Based Feline Medicine

32 – THE CAT WITH SIGNS OF ACUTE SMALL BOWEL DIARRHEA 715

non-regenerative anemia, increases in liver enzyme Treatment
concentrations, mild hypoalbuminemia and mild hyper-
The key to successful treatment of IBD is to have a cor-
glycemia.
rect diagnosis (and that is a real challenge).
Fecal examination (flotation, direct exam, cytology) is
Even if food allergy/intolerance has been ruled out,
essential to rule out parasitism.
a highly digestible, hypoallergenic or elimination
Ultrasound examination is very important, not only diet is important in the treatment of IBD. Cats with
in evaluation of the abdomen for structural abnormali- IBD have an abnormal gut immune system, thus the
ties, but especially for assessing bowel wall thickness presence of additional dietary antigens will only
and lymph node enlargement, which have been serve to exacerbate the inflammatory response.
shown to correlate well with the severity of IBD.
The mainstay of treatment of IBD in cats is immunosup-
Ultrasound is also important, as it may allow fine-
pressive doses of prednisolone (2–4 mg/kg/day PO).
needle aspiration of abnormalities which facilitate
diagnosis, but also will help determine the best Metronidazole (10–15 mg/kg q 12 h PO) is also very
approach to take when obtaining the biopsies (full thick- effective, and in some cats, may be as effective as
ness vs. endoscopic). steroid therapy. Many clinicians start with metronida-
zole and dietary therapy, and then add prednisolone if
Radiography, including contrast studies, has not been
the response to treatment is incomplete.
shown to be helpful in differentiating cats with IBD
and those with other diseases. In cats with severe IBD that is not responsive to
metronidazole, prednisolone and dietary therapy, cyto-
Ultimately, endoscopic examination or a surgical
toxic drugs may be considered. However, most cats
exploratory will be necessary to obtain biopsies of the
with IBD do not require additional cytotoxic drug
GI tract. Endoscopy is less invasive and allows visuali-
therapy, to manage their disease. Drugs have may be
zation of the mucosal surface, which may assist in the
2
considered include chlorambucil (2 mg/m ), azathio-
evaluation of the cat. Multiple (6–8) biopsies should
prine (0.3 mg/kg EOD) and cyclosporine (5 mg/cat/day).
be taken from multiple sites (stomach, duodenum,
CBCs should be monitored every 2–3 weeks to detect
ileum and colon), even if there is no visible evidence of
myelosuppression early.
disease.
Cats with a poor response to treatment or recurrent
Since there are no simple, easy tests for food intoler-
disease should be carefully re-evaluated (including
ance or food allergy, dietary elimination trials should
multiple GI biopsies) to be sure that the diagnosis is
be conducted in all cats with signs of IBD or that have
correct. Lymphoplasmacytic enteritis can be mistaken
inflammatory infiltrates of the GI tract.
for intestinal lymphoma in the early stages or a new
problem may have developed.
Differential diagnosis
TUMORS OF THE SMALL INTESTINE*
The list of diseases that may mimic, cause or compli-
cate IBD (e.g. cause GI inflammation and similar
Classical signs
clinical signs) is extensive: systemic diseases (hyper-
thyroidism, pancreatic disease, liver disease, feline ● Chronic, progressive vomiting that may
viral diseases, toxoplasmosis), parasitic diseases include hematemesis.
(nematodes, Giardia, Cryptosporidia, other parasites ● Weight loss and anorexia may be the
such as coccidia, entamoeba), bacterial infection earliest, and most consistent signs.
(Helicobacter, Campylobacter, Salmonella, Clostridia, ● Lethargy or depression are also common,
etc.), metabolic diseases (exocrine pancreatic insuffi- especially later in the course.
ciency, serum cobalamin or folate deficiency), nutri- ● Diarrhea is more common with infiltrative
tional disorders (food intolerance), immunological neoplasms.
conditions (food allergy) and neoplasia (lymphoma,
adenocarcinoma, mast cell tumor). See main reference on page 675 for details.