Sporotrichosis in Canines and Felines - Blackwell's Veterinary Consult PDF

1282 Blackwell’s Five-Minute Veterinary Consult Sporotrichosis CBC/BIOCHEMISTRY/URINALYSIS None unless associated with generalized...

1282 Blackwell’s Five-Minute Veterinary Consult Sporotrichosis CBC/BIOCHEMISTRY/URINALYSIS None unless associated with generalized disease. ­ BASICS ­ FOLLOW-UP OTHER LABORATORY TESTS OVERVIEW Cultures of affected tissue preferred; swab PATIENT MONITORING Zoonotic fungal disease affecting the culture may be adequate Reevaluation, including assessment of liver integument, lymphatics, or generalized. Caution: This is a zoonotic disease; enzymes, recommended every 2–4 weeks. Caused by inoculation of the ubiquitous laboratory personnel must be warned of the PREVENTION/AVOIDANCE dimorphic fungus Sporothrix schenckii into potential differential diagnosis. N/A subcutaneous tissue. Serologic testing and PCR assays are EXPECTED COURSE AND PROGNOSIS SIGNALMENT available. Failure of response to therapy possible. Cat and dog (less common). DIAGNOSTIC PROCEDURES Fluconazole and terbinafine remain SIGNS Cytology of exudates—cigar- to round- relatively untested but may show promise for Dogs (cutaneous form)—numerous shaped yeast found intracellularly or free in treatment. nodules that may drain or crust; most lesions the exudates with pyogranulamatous located on the head, dorsal muzzle; inflammation. occasionally on the chest, or disseminated on Biopsy—organisms usually numerous, the body and on the limbs. especially in cats; fungal stains (periodic acid– Cats (cutaneous form)—lesions appear Schiff or Gomori’s methamine silver) may aid ­ MISCELLANEOUS initially as wounds or abscesses mimicking in the diagnosis; the absence of demonstrable ZOONOTIC POTENTIAL wounds associated with fighting. organisms in tissues from dogs does not Caution: This is a zoonotic disease. Cutaneolymphatic form—usually an preclude diagnosis; pyogranulomatous Client education is of paramount extension of the cutaneous form through the inflammation with few mast cells, eosinophils, importance. lymphatics, resulting in the formation of new and plasma cells. Radiographs—evidence of Absence of a break in the skin does not nodules and draining tracts or crusts; lympha­ irregular periostal proliferation. protect against the disease. denopathy is common. Immunohistochemistry might be useful for an Reports of zoonotic transmission from bites Disseminated form—systemic signs early diagnosis of sporothricosis in cats. High and scratches from rodents, parrots, cats, including lameness, respiratory symptoms sensitivity reported with immuno­histochemistry dogs, horses, and armadillos. (nasal discharge, sneezing, stertorous to diagnose sporothricosis in dogs. Clinically healthy cats sharing a household S breathing), anorexia and weight loss also ELISA— screening tool for the detection of with an infected cat may be a source of reported in dogs. specific S. schenckii antibodies in cats with infection. sporotrichosis. CAUSES & RISK FACTORS ABBREVIATIONS Dogs—hunting dogs from puncture ELISA = enzyme-linked immunosorbent wounds associated with thorns or splinters. assay. Cats—intact male outdoor cats: Healthy ­Suggested Reading cats may have a minor role in sporotrichosis ­ TREATMENT Silva J, Miranda L, Menezes R, et al. transmission Zoonotic; outpatient therapy may be a Comparison of the sensitivity of three Animals exposed to soil rich in decaying consideration but increases the potential for methods for the early diagnosis of organic debris. human exposure. sporotrichosis in cats. J Comp Pathol 2018, Exposure to infected animals or clinically 160:72–78. healthy cats sharing a household with an Authors W. Dunbar Gram and Andhika affected cat. Putra Immunosuppressive disease. ­ MEDICATIONS Consulting Editor Alexander H. Werner Resnick DRUG(S) OF CHOICE Acknowledgment The authors and editors Dogs—ketoconazole 5–15 mg/kg PO acknowledge the prior contribution of Holly q12h, itraconazole 5–10 mg/kg PO q24h, ­ DIAGNOSIS terbinafine 30–40 mg/kg PO q24h given Dutton. Caution: This is a zoonotic disease and proper with food, administered until 1 month after precautions should be taken to prevent clinical resolution; resolution usually occurs exposure; the absence of a break in the skin within 3 months. Disseminated disease— does not protect against the disease. Cats may combination of amphotericin B and act as reservoirs for S. schenckii and can itraconazole is recommended; terbinafine may transmit the infection to humans by a bite or also be effective. scratch. Cats—itraconazole 5–15 mg/kg PO q24h DIFFERENTIAL DIAGNOSIS or divided q12h for a minimum of 1 month Infectious—bacterial (deep) and fungal beyond clinical cure; compounded infection (e.g., cryptococcosis, blastomycosis, formulations of itraconazole are not feline leprosy, histoplasmosis). recommended due to inconsistent absorption. Neoplasia. Granulomas caused by foreign bodies. Parasites—Demodex, Pelodera, Leishmania.