Page 1474 - Small Animal Internal Medicine, 6th Edition

1446 PART XIV Infectious Diseases

infection is suspected and oral doxycycline cannot be admin- Vaginitis generally results from overgrowth of normal
istered, intravenous administration of ampicillin at 20 mg/ flora secondary to primary diseases, including herpesvirus
VetBooks.ir kg IV q6h is indicated followed by doxycycline to eliminate infection, urinary tract infection, foreign bodies, vulvar
or vaginal anomalies, vaginal or vulvar masses, or urinary
the renal carrier phase (Sykes et al., 2011). Treatment for
pyelonephritis and other chronic, complicated urinary tract
from overgrowth of flora and resolution of the primary
infections should be continued for at least 4 to 6 weeks. incontinence. In dogs and cats with bacterial vaginitis
Urinalysis, culture, and antimicrobial susceptibility testing insult, broad-spectrum antibiotics, including amoxicillin,
should be performed 7 days after starting treatment and 1 trimethoprim-sulfonamide, first-generation cephalosporins,
week after cessation of treatment. It is possible that shorter tetracycline derivatives, and chloramphenicol, are typically
duration of therapy for complicated cases could be consid- successful. Because Mycoplasma and Ureaplasma organisms
ered. Some infections cannot be eliminated and require are part of the normal vaginal flora, providing a clinical
administration of pulse or continuous antibiotic therapy, but disease association is virtually impossible; positive cultures
an optimal protocol will need to be developed on a case-by- do not confirm disease because of the organism (see Chapter
case basis. 94). Hence a positive vaginal culture from an asymptomatic
Mycoplasma and Ureaplasma infections have been docu- dog (excluding B. canis) is meaningless.
mented in dogs with clinical signs of urinary tract infections In all dogs and cats with pyometra, ovariohysterectomy or
(Ulgen et al., 2006). If poor response to penicillin derivatives, medically induced drainage of the uterus is imperative. Anti-
cephalosporins, or trimethoprim-sulfonamide is observed, biotic treatment is for the bacteremia that commonly occurs
culture for Mycoplasma spp. should be performed. Chlor- concurrently (i.e., E. coli and anaerobes). Animals with clinical
amphenicol, doxycycline, or quinolone treatment should be signs of bacteremia or sepsis should be treated with a four-
effective for Mycoplasma and Ureaplasma infections. quadrant antibiotic choice (see Table 92.5). Broad-spectrum
Most bacterial prostatic infections involve gram-negative antibiotics with efficacy against E. coli, such as potentiated
bacteria. During acute prostatitis, almost all antibiotics sulfas or amoxicillin-clavulanate, are appropriate empiri-
penetrate the prostate well because of inflammation; cal choices pending the results of culture and antimicrobial
trimethoprim-sulfonamide or veterinary fluoroquinolones susceptibility testing. Potentiated sulfas and the quinolones
are usually effective. After reestablishment of the blood- commonly are effective for E. coli but are not as effective as
prostate barrier in dogs with chronic prostatitis, the acidic other drugs for the treatment of anaerobic infections in vivo.
prostatic fluid allows only the basic antibiotics (pK a less than Ampicillin, amoxicillin, and first-generation cephalospo-
7) to penetrate well (see Table 92.8). Chloramphenicol, rins achieve good concentrations in milk and are relatively
because of its high lipid solubility, also penetrates prostatic safe for the neonate; therefore they can be used in the empiri-
tissue well. In acute prostatitis, administration of acidic anti- cal treatment of mastitis. Chloramphenicol, quinolones, and
biotics, including penicillins and first-generation cephalo- tetracycline derivatives should be avoided because of poten-
sporins, may initially penetrate well, lessening clinical signs tial adverse effects on the neonate.
of disease but not eliminating the infection. This predisposes
to chronic bacterial prostatitis and prostatic abscessation. Suggested Readings
For this reason, the use of penicillins and first-generation Bowman DD, et al. Treatment of naturally occurring, asymptomatic
cephalosporins is contraindicated for the treatment of Giardia sp. in dogs with Drontal Plus flavour tablets. Parasitol
urinary tract infections in male dogs. In dogs with chronic Res. 2009;105(suppl 1):S125–S134.
prostatitis, antimicrobial therapy should be continued for at Calvert CA, Thomason JD. Cardiovascular infections. In: Greene
least 6 weeks and should be based on culture and sensitivity CE, eds. Infectious Diseases of the Dog and Cat. 4th ed. Elsevier;
2012:912–923.
results of urine or prostatic aspirates. Most agents isolated Fenimore A, et al. Bartonella spp. DNA in cardiac tissues from dogs
are susceptible to trimethoprim-sulfonamide or veterinary in Colorado and Wyoming. J Vet Intern Med. 2011;25:613–616.
fluoroquinolones. Urine and prostatic fluid should be cul- Fenimore A, et al. Evaluation of metronidazole with and without
tured 7 days and 28 days after therapy. Whether shorter Enterococcus faecium SF68 in shelter dogs with diarrhea. Top
durations of treatment could be considered is unknown. Companion Anim Med. 2017;32:100.
Brucella canis causes a number of clinical syndromes in Fiechter R, et al. Control of Giardia infections with ronidazole and
dogs, including epididymitis, orchitis, endometritis, still- intensive hygiene management in a dog kennel. Vet Parasitol.
births, abortion, discospondylitis, and uveitis. Ovariohyster- 2012;187:93.
ectomy or neutering lessens contamination of the human Hillier A, et al. Guidelines for the diagnosis and antimicrobial
environment. (See Chapter 99 for a discussion of the zoo- therapy of canine superficial bacterial folliculitis (Antimicrobial
notic potential.) Long-term antibiotic administration usually Guidelines Working Group of the International Society for Com-
panion Animal Infectious Diseases). Vet Dermatol. 2014;25:163.
does not lead to a complete cure (Wanke et al., 2006). Some Jang SS, et al. Organisms isolated from dogs and cats with anaerobic
dogs become antibody-negative, but the organism can still infections and susceptibility to selected antimicrobial agents. J
be cultured from tissues. Several antibiotic protocols have Am Vet Med Assoc. 1610;210:1997.
been suggested for dogs with brucellosis (see Table 92.8). Jergens AE, et al. Fluorescence in situ hybridization confirms clear-
However, owners should be carefully counselled concerning ance of visible Helicobacter spp. associated with gastritis in dogs
zoonotic risks before initiating treatment. and cats. J Vet Intern Med. 2009;23:16–23.