Page 668 - Clinical Small Animal Internal Medicine

636 Section 6 Gastrointestinal Disease

antigenic modification (e.g., novel protein source or pro- cyclosporin at 5 mg/kg every 24 hours for 10 weeks. A
VetBooks.ir tein hydrolysate). Whichever type of diet is chosen, it response to prednisolone has been shown in up to only
50% of dogs with CE, so if more severe disease is present
must be palatable and introduced in gradually increasing
amounts over 4–7 days. In dogs with FRD, a clinical
immunosuppressives can be an option. Many steroid‐
response is usually observed within 1–2 weeks of chang- or severe side‐effects of steroids are anticipated, other
ing the diet. One study demonstrated that dogs that refractory canine CE cases can be rescued by cyclosporin
2
respond to diet tended to be younger and had higher single therapy. In cats, use chlorambucil 2–6 mg/m
serum albumin concentrations and predominantly signs q24h with prednisolone if there is inadequate response
of large bowel diarrhea than dogs that did not respond to to glucocorticoid treatment alone. Hematologic param-
diet. FRD is highly prevalent among dogs with IBD (at eters should be monitored regularly if chlorambucil is
least 60–70%) and a favorable response to elimination or used. If the patient responds then the medication can be
hydrolyzed diets within two weeks has been shown to be tapered gradually, starting with the steroid, to an q48h
associated with a very good prognosis over one year after dosing regimen.
diagnosis. It is important to note that in the studies that Budesonide is a glucocorticoid medication that has
show these good outcome measures, the dogs were kept been preliminarily shown to be successful in the treat-
on the diet for at least 12 weeks after diagnosis before ment of canine IBD. However, hypothalamic‐pituitary‐
they were switched back to their original diet. adrenal suppression and development of a steroid
hepatopathy have been demonstrated in dogs, so the
hepatic fist‐pass effect of this drug in dogs may not be as
ARD: Antibiotics
great as in human beings. An optimal dose has not yet
An antibiotic trial typically involves oral administration been determined, although anecdotally a dose of 1 mg/
2
of tylosin, 10–15 mg/kg q8h, oxytetracycline 20 mg/kg m every 24 hours orally has been recommended. The
q8h, or metronidazole 10 mg/kg q12h. A positive response rate to budesonide was shown to be similar to
response suggests ARD. The dog is typically maintained the use of prednisolone (about up to 60%), and it should
on antibiotics for 28 days; if signs recur after stopping therefore be reserved for dogs that are known to respond
then long‐term antibiotic therapy with tylosin 5 mg/kg is to steroids but suffer severe side‐effects. Some dogs will,
used orally every 24 hours. In a recent large retrospective however, still develop side‐effects of steroid administra-
study where all dogs were sequentially treated, only 16% tion while on budesonide, so owners should be warned
of dogs were ARD. All ARD dogs relapsed shortly after about this. Sulfasalazine (20–50 mg/kg q8h for 3–6
discontinuation of the antibiotics was attempted, making weeks) and related drugs are often used in dogs when
long‐term management of these patients difficult. An IBD is limited to the large intestine. However, as side‐
additional decision‐making factor may be the increasing effects include keratoconjunctivits sicca, tear production
problems with antibiotic resistance in our dog popula- should be monitored regularly.
tions, making justifications of long‐term treatment with
antibiotics difficult. There is also accumulating evidence Treatment of Patients with Severe Protein‐
that antibiotic treatment has long‐lasting effects on the Losing Enteropathy
intestinal microbiome, which may lead to lasting dysbio-
sis and in itself could amplify inflammation in the intes- Protein‐losing enteropathy is a recognized complication
tine. Many of these patients will therefore need steroids in a subset of CE cases and a low serum albumin concen-
or other immunosuppressives to control their clinical tration has been shown to be a poor prognostic indicator
signs long term. for CE. Patients with albumin concentrations below
1.5 g/dL are at risk of developing ascites, pleural effusion,
and subcutaneous edema. Many of these patients will
Anti-inflammatory and Immunosuppressive succumb to the disease within the first 1–2 months of
Therapy
starting prednisolone treatment. As some studies have
Patients that do not respond to a diet or antibiotic trial shown better outcome with single‐therapy cyclosporin
are usually administered oral prednisolone 2 mg/kg at 5–10 mg/kg PO SID, this latter regime may be a better
every 24 hours that is tapered over an eight‐week period. option for many of these patients. One recent study has
However, as the side‐effects of glucocorticoids are usu- also shown that the combination of prednisolone and
ally more marked in large‐ than small‐breed dogs, aza- chlorambucil was superior to prednisolone and azathio-
thioprine may be combined with glucocorticoid prine for survival. Evaluation of hemostatic function in
treatment at a faster taper in dogs weighing more than these patients is recommended to ascertain if hyperco-
30 kg. If there is poor response to immunosuppression or agulability has developed as a consequence of enteric
a relapse is seen after tapering, then consider oral protein loss. Concurrent therapy with ultra‐low-dose