Response of feline eosinophilic plaques and lip ulcers to amoxicillin
trihydrate-clavulanate potassium therapy: a randomized, double-blind
placebo-controlled prospective study.
Author(s): Wildermuth BE, Griffin CE, Rosenkrantz WS.
Affiliation(s): Animal Dermatology Clinic, 5610 Kearny Mesa Road Suite B1, San Diego, CA 92111,
Publication date & source: 2012, Vet Dermatol. , 23(2):110-8, e24-5
In this study, we evaluated the treatment of feline eosinophilic plaques and lip
ulcers with amoxicillin trihydrate-potassium clavulanate (Clavamox(®); Pfizer
Animal Health). Nineteen cats with clinical and cytological findings consistent
with eosinophilic plaques and/or lip ulcers were enrolled. Lesions were
photographed and their areas measured in square centimetres before and after 21
days of therapy with either flavoured amoxicillin-clavulanate suspension or
flavoured placebo suspension. Sixteen cats completed the study, with nine plaque
lesions (four treatment and five placebo) and eight lip ulcer lesions (four
treatment and four placebo) included in the analysis. All lesions were shown to
have infection, with bacterial phagocytosis present on cytological examination.
Coagulase-positive staphylococci were the most commonly isolated bacteria. The
amoxicillin-clavulanate-treated eosinophilic plaque group had a statistically
significant 96.2% reduction in mean lesion size (-7.60 cm(2), P = 0.0078) and an
80% reduction in mean percentage of microscopic fields demonstrating evidence of
bacterial infection (P < 0.0001), whereas the placebo group did not. The
amoxicillin-clavulanate-treated lip ulcer group had a 42.6% decrease in mean
lesion size (-0.25 cm(2), P = 0.4125) and the placebo group a 36.6% increase
(+0.49 cm(2), P = 0.1575), although neither change was statistically significant.
The amoxicillin-clavulanate-treated lip ulcer group had a statistically
significant 65.0% reduction in mean percentage of microscopic fields
demonstrating evidence of bacterial infection (P < 0.0001), while no significant
reduction was observed in the placebo group. A suspension of amoxicillin
trihydrate-potassium clavulanate is an effective monotherapy for the treatment of
feline eosinophilic plaques.