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Dermatophytosis 249

• AVOID the use of bleach; it has no detergency • Concurrent focal therapy colony-forming units per plate. Recovery is
effect, has not been shown to be more ○ Use concurrent focal topical therapy for associated with fewer colony-forming units
VetBooks.ir inactivated after dilution, and when exposed of residual infection. Apply miconazole • Weekly fungal cultures are cost-effective; Diseases and Disorders
on the plate. Both cure and poor treatment
hard-to-treat areas that are often nidus
effective than other disinfectants, is readily
compliance are best identified this way.
to light, is an irritant and damages surfaces.
vaginal cream 2% to lesions in hard to
It is an animal and human health risk and
irritant. treat areas such as the face and peri- the first and second negative cultures can
be detected sooner than with q 2 week or
ocular area. For ears, use miconazole- or
• Carpets can be decontaminated by steam ketoconazole-containing ear rinse to q 4 week intervals.
cleaning or two washings with a beater-brush disinfect hairs in bell of ear. Apply daily.
carpet shampooer. Systemic Therapy PROGNOSIS & OUTCOME
• Important to stress to owners that spores do • Terbinafine has the lowest minimum
not multiply in the environment and do not inhibitory concentration (MIC) against • Prognosis is good, even for cats with long
invade homes like mildew or black mold. dermatophytes. It is the drug of choice for hair.
Spores in the environment are dormant and dogs and an alternative to itraconazole for • Terbinafine and itraconazole are well toler-
are not alive. cats. ated. Most animals achieve cure in 4-8 weeks.
• Furnace filters are excellent at trapping • Terbinafine 30-40 mg/kg PO q 24h or week • Cats or dogs that do not achieve a cure
spores and hairs and do not spread spores on/week off until cured usually have an underlying medical problem
throughout the home. • Itraconazole 5 mg/kg PO q 24h, week on/ causing immunosuppression.
week off (i.e., 7 days of treatment, 7 days
Pet-Focused Treatment without until mycologic cure) is the systemic PEARLS & CONSIDERATIONS
Topical therapy: drug of choice for cats. Cost limits its use in
• Topical therapy is equally important as sys- dogs. Pulse therapy works because the drug Comments
temic therapy. It is the only way to disinfect accumulates in hair and skin. Do not use • Clipping of the haircoat is not needed unless
the haircoat and kill infective spores on compounded formulations of this product the coat is so matted that topical therapy
hairs. in cats or dogs. cannot be applied adequately.
• Comb haircoat before application to remove • Ketoconazole 5-10 mg/kg PO q 24h is an • Combing the animal’s coat with a flea comb
loose hairs. option for dogs but has higher MIC than to remove broken hairs and decrease infective
• Apply topical therapy twice per week to the terbinafine or itraconazole. Avoid use in cats load is an effective alternative to clipping.
whole body, being sure to soak hairs and the due to gastrointestinal intolerance.
skin. • Fluconazole has poor antifungal efficacy Prevention
• Rinses against dermatophytes and highest MIC • Include room light and Wood’s lamp
○ Lime sulfur solution: 1 16 dilution (8 compared to itraconazole, terbinafine, examinations as part of the examination
ounces in 1 gallon of tap water; 30 mL ketoconazole, or griseofulvin. of all new pets. Perform fungal cultures for
in 480 mL of tap water). Use lukewarm • Griseofulvin is less effective than itraconazole high-risk individuals. Use topical therapy
water, and be sure to soak the skin and and terbinafine and is no longer recom- pending results when infection suspected.
hair; do not rinse. Towel dry. In some mended for use. • Catteries should routinely quarantine cats
countries, agricultural products are used. • Lufenuron is not effective for treatment or pending fungal culture results for all new
They are labeled 23% calcium polysulfide prevention in cats. additions or cats returning to the facility.
or 23% sulfur sulfide, which is equivalent
to a 76.9% lime sulfur solution. The Recommended Monitoring Technician Tips
same dilution ( 16 ) is therefore required • Animals responding to therapy show rapid Create a positive control for the Wood’s lamp
1
to obtain the same solution dilution. clinical cure, some as early as 1-2 weeks after examination by pressing clear acetate tape to
○ Enilconazole topical solution 0.2% (dilute starting therapy. a glowing lesion and then mounting it on a
per label instructions); in cats, prevent • Monitor M. canis infections using a Wood’s glass slide. Seal edges with fingernail polish.
grooming with Elizabethan collar until lamp. Any evidence of fluorescence on the
dry. hair shaft makes the animal high risk for SUGGESTED READING
• Shampoos still being infected. Glowing hair tips are Moriello KA, et al: Diagnosis and treatment of der-
○ Use combination of chlorhexidine + often seen in cured animals and represent matophytosis in dogs and cats. Clinical consensus
miconazole, chlorhexidine + ketoconazole, residual pigmentation. guidelines for the World Association of Veterinary
or chlorhexidine + climbazole. Dilute 1 : 4 • PCR can be used to determine mycologic Dermatology. Vet Dermatol 28:266-303, 2017.
before application, and shampoo for at cure, but it detects viable and nonviable AUTHOR: Karen Moriello, DVM, DACVD
least 3-5 minutes. Disadvantage is that fungal DNA. Wash animal in shampoo before EDITOR: Manon Paradis, DMV, MVSc, DACVD
this does not have residual activity. testing to remove residual fungal DNA. A
• Mousse negative test result indicates mycologic cure;
○ Leave-on climbazole mousse can be used a positive test may be from nonviable DNA.
in patients that cannot be wetted (e.g., • If using fungal cultures, perform weekly
animals with bandages or upper respiratory or start when Wood’s lamp examinations
infections). are negative. Monitor the number of

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