Acne—Dogs PDF - Canine and Feline, 7th Edition

Canine and Feline, Seventh Edition 15 Acne—Dogs A...

Canine and Feline, Seventh Edition 15 Acne—Dogs A IMAGING Gentamicin/steroid-containing ointments N/A for the ears can be applied to localized lesions DIAGNOSTIC PROCEDURES twice daily; most useful for lesions on the ­ BASICS chin, as the pet cannot lick this area. Constant Impression cytology will help determine if OVERVIEW bacteria or yeast are present. long-term use over months may cause alopecia Also (more correctly) muzzle folliculitis and Skin scrape—demodicosis. and cutaneous atrophy: limit frequency and furunculosis. Dermatophyte culture—dermatophytosis. duration of application. Chronic inflammatory disorder of the chin Bacterial culture and sensitivity testing—in Systemic and lips of mostly young animals. patients with suppurative folliculitis and Antibiotics based on culture and sensitiv- Characterized by folliculitis and furunculo- furunculosis that are nonresponsive to initial ity—when indicated (e.g., cephalexin, sis; almost never comedogenic as seen in “true antibiotic selection. 22–30 mg/kg PO q12h for 2–4 weeks). acneiform” lesions of human beings. Biopsy—histologic confirmation for cases Oral corticosteroids: tapering dosages of Recognized almost exclusively in short- in which diagnosis is in question. prednisolone (initial 0.5 mg/kg/day) to coated breeds. reduce significant inflammation; not for Genetic predisposition, local trauma, and PATHOLOGIC FINDINGS Clinical signs and histopathologic findings continued use. allergic disease often play a role. Evaluate for and manage concurrent are diagnostic. SIGNALMENT Characterized histopathologically by allergic/atopic skin disease. Dogs, often younger, sometimes puppies. folliculitis and furunculosis. CONTRAINDICATIONS/POSSIBLE Predisposed short-coated breeds—boxer, Bacteria—not always isolated from lesions INTERACTIONS Doberman pinscher, English bulldog, Great in early stages. Topical steroids—may cause adrenal Dane, Weimaraner, mastiff, Rottweiler, As disease progresses, papules enlarge and suppression and thinning of skin with German shorthaired pointer, pit bull terrier. rupture, promoting a suppurative folliculitis frequent or constant use. SIGNS and furunculosis. Ventral chin and lip margins may have few to numerous erythematous papules and sometimes bullae. These may coalesce to form plaques. ­ FOLLOW-UP ­ TREATMENT Initial lesions are inflammatory and sterile; Reduce behavioral trauma to the chin (e.g., PATIENT MONITORING bacteria may not be isolated and lesions may Continue antibiotics until lesions have rubbing on the carpet, chewing bones that not respond to antibiotics. increase salivation). healed. Advanced lesions may contain pus or blood, Repeat bacterial culture/sensitivity if lesions Frequent cleaning with chlorhexidine- indicating secondary deep bacterial folliculitis containing pads, shampoos, or solutions can worsen. and furunculosis. Discontinue topical corticosteroids when be helpful, but instruct owners not to scrub at Lesions may be pruritic, some are painful the area. possible. on palpation, but most are nonpainful and Gentamicin/steroid-containing ointments EXPECTED COURSE AND PROGNOSIS nonpruritic. for the ears work well on the chin when Long-term topical treatment may be Chronic and pruritic lesions may become applied twice daily. required. hyperpigmented, lichenified, scarred, and If topicals are not helpful by themselves, Chronic scarring may be prevented by early alopecic. add oral antibiotics based on positive cytology and aggressive therapy. CAUSES & RISK FACTORS and culture and sensitivity testing. Several short-coated breeds appear to be Severe cases may necessitate short courses of genetically predisposed to acne. Lesions may oral steroids. be worse in allergic individuals. Evaluate for underlying allergic/atopic disease and institute proper therapy for ­ MISCELLANEOUS diagnosis and control of these diseases; control ASSOCIATED CONDITIONS of allergic disease may permit resolution of Allergic/atopic disease may cause and muzzle folliculitis and furunculosis. exacerbate this condition. ­ DIAGNOSIS Instruct owners to avoid squeezing the ­Suggested Reading DIFFERENTIAL DIAGNOSIS lesions; trauma may make inflammation Miller WH, Griffin CE, Campbell KL. Dermatophytosis. worse. Muzzle folliculitis and furunculosis. In: Demodicosis. Muller & Kirk’s Small Animal Dermatology, Juvenile cellulitis. 7th ed. St. Louis, MO: Elsevier, 2013, pp. Contact dermatitis. 201, 640. With other symptoms, consider allergic/ atopic disease as playing a role. ­ MEDICATIONS Author Melissa N.C. Eisenschenk Consulting Editor Alexander H. Werner CBC/BIOCHEMISTRY/URINALYSIS DRUG(S) Resnick N/A Topical Acknowledgment The author and editors OTHER LABORATORY TESTS Daily cleaning with chlorhexidine-containing acknowledge the prior contribution of Karen N/A pads, shampoos, or solutions can be helpful; Helton Rhodes. instruct owners not to scrub at the areas.