Small Animal Dermatology, 3rd edition

538 DISEASES/DISORDERS

 Surgery: surgical drainage should accompany medical therapy; thoracotomy tube for

pleural effusion; debridement of draining tracts and lymph nodes.

Drugs of Choice

 Culture organism and perform antibiotic sensitivity testing.

 Nocardiosis: empirical choices (or pending culture results):
Sulfadiazine-trimethoprim combinations (15–30 mg/kg PO q24h)
Aminoglycosides: gentamicin 9–12 mg/kg (dogs) or 5–8 mg/kg (cats) IV, IM, SC

q24h; amikacin 15–30 mg/kg (dogs) or 10–15 mg/kg (cats) IV, IM, SC q24h

Cycline antibiotics: tetracycline 15–20 mg/kg PO TID; doxycycline 10 mg/kg PO

q24h; minocycline 5–12.5 mg/kg PO BID

Erythromycin: 10–20 mg/kg PO q8h; or combined with ampicillin 20–40 mg/kg

PO q8h or amoxicillin 6–20 mg/kg PO BID to TID; or clarithromycin 7.5 mg/kg

PO BID

Amoxicillin plus an aminoglycoside: synergistic combination; consider in any

serious infection when culturing is not possible or is pending

Chloramphenicol: 40–50 mg/kg PO TID (dogs); 12.5–20 mg/kg PO BID (cats)

Fluoroquinolones (third or fourth generation) may be effective.

 Actinomycosis: empirical choices (or pending culture results):
Amoxicillin 6–20 mg/kg PO BID to TID
Erythromycin: 10–20 mg/kg PO TID; or combined with ampicillin 20–40 mg/kg

PO TID.

 Average treatment period is 6 weeks; however, medical treatment should extend sev-

eral weeks past apparent remission of the disease.

COMMENTS

 Prognosis is guarded.

 Aggressive early therapy when lesions are localized improves outcome.

 Tetracyclines (cats): may cause fever up to 41.5◦C (107◦F); discontinue and replace

if fever increases during therapy.

 Monitor carefully for fever, weight loss, seizures, dyspnea, and lameness the first year

after apparently successful therapy because of the potential for bone and CNS involve-

ment.

 Treatment should be continued for at least 1 month after clinical remission.