Page 471 - Small Animal Internal Medicine, 6th Edition

CHAPTER 28 General Therapeutic Principles 443

Tylosin (10-20 mg/kg PO q24h or divided q12h) is com- dogs or cats. Sole-agent therapy of Helicobacter pylori in
monly used to treat ARE and clostridial colitis. Tetracycline people is typically unsuccessful, but some dogs and cats seem
VetBooks.ir (22 mg/kg PO q12h) has also been used for ARE. The cli- to respond to erythromycin or amoxicillin as a sole agent. If
high doses of erythromycin (22 mg/kg PO, twice daily) cause
nician should be prepared to treat the patient for 3 weeks
before deciding that therapy for ARE has been unsuccessful.
Pets occasionally have enteritis caused by a specific bac- vomiting, the dose may be lowered to 10 to 15 mg/kg twice
daily. A 10- to 14-day course of treatment appears adequate
terium, but this is not necessarily an indication for antibiot- for most animals, although recurrence of infection is
ics. Clinical signs resulting from some bacterial enteritides probable.
(e.g., salmonellosis, enterohemorrhagic Escherichia coli)
generally do not resolve more quickly when the animal is
treated with antibiotics, even those to which the bacteria are PROBIOTICS/PREBIOTICS
sensitive.
Dogs and cats with viral enteritis but without obvious Administering live bacteria or yeast in the food with the
systemic sepsis may reasonably be treated with antibiotics if intent to produce a beneficial effect is called probiotic therapy.
secondary sepsis is likely to occur (e.g., those with or likely Administering a specific dietary substance to specifically
to develop neutropenia). First-generation cephalosporins increase or decrease the numbers of specific bacteria is called
(e.g., cefazolin) are often effective for such use. prebiotic therapy. Concurrent use of probiotics and prebiot-
If systemic or abdominal sepsis is suspected to have origi- ics is called symbiotic therapy. Currently there are only a few
nated from the alimentary tract (e.g., septicemia caused by reports purporting a clear benefit in dogs or cats.
parvoviral enteritis, perforated intestine), broad-spectrum Lactobacillus, Bifidobacterium, and Enterococcus are bac-
antimicrobial therapy is indicated. Antibiotics with an excel- teria typically administered to dogs. These bacteria are
lent aerobic gram-positive and anaerobic spectrum of action believed to stimulate Toll-like receptors on the intestinal epi-
(e.g., ampicillin plus sulbactam [Unasyn] 20 mg/kg IV q8h thelial cells and thereby affect cytokine production. The ben-
or clindamycin, 11 mg/kg IV q8h) combined with antibiotics eficial effect seems to last only as long as the bacteria are
with excellent activity against most aerobic bacteria (e.g., being administered. These bacteria rarely become perma-
amikacin, 25 mg/kg IV q24h; or enrofloxacin, 15 mg/kg IV nently established in the gastrointestinal microflora. Not all
q24h [use 5 mg/kg in cats]) are often effective. To improve probiotics sold in drug or grocery stores contain what the
the anaerobic spectrum, especially if a cephalosporin is used label states, which may be at least partially responsible for
instead of ampicillin, the clinician may include metronida- why efficacy has not be demonstrated. In general, large
zole (10 mg/kg IV, q8-12h). Alternatively, a second- numbers of bacteria appear to be necessary, which explains
generation cephalosporin (e.g., cefoxitin, 30 mg/kg IV why feeding yogurt (which contains relatively modest
q6-8h) may be used. In general, it takes at least 48 hours numbers of Lactobacilli) is typically ineffective.
before the clinician can ascertain whether the therapy is
being effective.
Despite the clinical imperative to control life-threatening FECAL TRANSPLANTATION
infection as quickly as possible, it is also important to be a
responsible member of the medical community, in this case Much work is being done on fecal transplantation as a means
specifically in regard to antibiotics effective against multi– of altering the intestinal bacterial flora and avoiding the need
drug-resistant infections. Some antibiotics are referred to as for antibiotics in dogs and cats with chronic intestinal dis-
“drugs of last resort” because there are bacteria for which eases. Currently, there is no consensus as to the best
only 1 or 2 antibiotics are still effective. Vancomycin, imipe- technique(s) or the appropriate indications. However, this
nem, meropenem, doripenem, the oxazolidinone linezolid might become an important alternative to antibiotic therapy.
(Zyvox), the streptogramin combination of dalfopristin and
quinupristin (Synercid), tigecycline (Tygacil), the lipopep-
tide daptomycin (Cubicin), moxifloxacin (Avelox), the ANTHELMINTIC DRUGS
glycopeptide telavancin, the oxazolidinone telithromycin
(Ketek®), and the fourth- and fifth-generation cephalospo- Anthelmintics are frequently prescribed for dogs and cats
rins (cefepime, cefpirome, ceftaroline, ceftobiprole) should with alimentary tract disease, even if parasitism is not the
not be used unless bacteria resistant to all other antibiotics primary problem. It is often reasonable to use these drugs
have been cultured and there is no other therapy that is empirically for the treatment of suspected parasitic infec-
expected to be effective. tions in animals with acute or chronic diarrhea. Selected
Helicobacter gastritis may be treated with various combi- anthelmintics are listed in Table 28.7.
nations of drugs. Currently, the combination of amoxicillin,
metronidazole, and bismuth seems effective in dogs and cats.
Antacids (i.e., omeprazole; see Table 28.4) and macrolides ENEMAS, LAXATIVES, AND CATHARTICS
(i.e., erythromycin or azithromycin; see pp. 515-516) have
been used in people, but they do not appear necessary in Enemas are classified as either cleansing or retention.