Page 754 - Problem-Based Feline Medicine

746 PART 9 CAT WITH SIGNS OF GASTROINTESTINAL TRACT DISEASE

● Systemic diseases (hyperthyroidism, pancreatic cyclosporine therapy must be monitored by checking
disease, liver disease, feline viral diseases, toxo- trough and peak drug levels.
plasmosis).
Cats with a poor response to treatment or recurrent
● Parasitic diseases (nematodes, Giardia, Crypto-
disease should be carefully re-evaluated, including -
sporidia, other parasites such as coccidia,
re-biopsy if indicated. Lymphoplasmacytic enteritis
Entamoeba).
can be mistaken for lymphoma in the early stage.
● Bacterial infection (Helicobacter, Campylobacter,
Cats with IBD have been reported to have concurrent
Salmonella, Clostridia, etc.).
reactivation of toxoplasmosis. Food allergy/intoler-
● Metabolic diseases (EPI, serum cobalamin or folate
ance is extremely difficult to differentiate from IBD
deficiency).
and in some cats finding the appropriate diet is a true
● Nutritional disorders (food intolerance/allergy).
challenge.
● Neoplasia (lymphoma, adenocarcinoma, mast cell
tumor).
INFLAMMATORY HEPATOBILIARY
Treatment
DISEASE (CHOLANGOHEPATITIS)
The first key to successful treatment of IBD is to have
a correct diagnosis, and that is a real challenge. Classical signs
Even if food allergy/intolerance has been ruled out, ● With lymphoplasmacytic forms, chronic
a highly digestible, hypoallergenic or elimination weight loss, anorexia, vomiting and icterus
diet is important in the treatment of IBD. Cats with are common signs.
IBD have an abnormal gut immune system, thus the ● In neutrophilic cholangitis, the disease is
presence of additional dietary antigens may serve to more acute in nature, and fever, depression
exacerbate the inflammatory response. A “sacrificial” and icterus are typical.
protein source may have to be used first, while the
bowel is still subject to a strong inflammatory response, See main reference on page 427 for details (The Yellow
before moving onto a more permanent food choice. Cat or Cat With Elevated Liver Enzymes).
The mainstay of treatment of IBD in cats is immuno-
suppressive doses of prednisolone (2–4 mg/kg/day
PO).
Clinical signs
Metronidazole (10–15 mg/kg q 12 h PO) is also very
Weight loss (often dramatic), anorexia, intermit-
effective, and in some cats, may be as effective as
tent vomiting, and icterus are the most common
steroid therapy. Many clinicians start with metronida-
signs in cats with lymphocytic cholangitis. These
zole and dietary therapy, and then add prednisolone if
cats often are middle aged, there is no breed or sex
the response to treatment is incomplete.
predisposition, and they have hepatomegaly. Con-
In cats with severe IBD that is not responsive to current pancreatitis and/or IBD is seen in some cats
metronidazole, prednisolone and dietary therapy, cyto- and their illness is more chronic and subacute. In
toxic drugs may be considered. However, most cats some cats, there is a waxing and waning course with
with IBD do not require additional cytotoxic periods of normalcy and a good appetite following
drug therapy to manage their disease, so a careful re- episodes of signs.
evaluation of the patient is indicated to be sure you
Ascites (high protein content) is more likely with the
have the correct diagnosis. Drugs that may be consid-
lymphoplasmacytic form, but it is rare.
2
ered include chlorambucil (2 mg/m ), azathioprine
(0.3 mg/kg EOD) and cyclosporine (5 mg/cat/day). Cats with neutrophilic cholangitis are more often
Hemograms should be monitored every 2–3 weeks male, febrile, depressed, icteric and have an acute
to detect myelosuppression, and if cyclosporine is used, onset of illness that is rapidly progressive.