ABSTRACT
Assessment of ocular discomfort caused by veterinary care products is less legitimately regulated than that caused by human care products. The Slug Mucosal Irritation (SMI) assay was adapted to evaluate canine hygiene shampoos to predict ocular discomfort. Experiments were performed using four commercial canine shampoos, a baby care product, and two controls (ArtTear® and BAC1%). Groups of 3 slugs were tested with 5% dilution of the 7 test substances. The negative control (ArtTear®) was the best tolerated. The baby care product Mixa bébé as well as Douxo Entretien Démêlant and Phlox Shampooing Entretien were classified to cause mild ocular discomfort. Together with the positive control (BAC 1%), Shampooing Physiologique Virbac and Physiovet Shampooing were considered to cause severe ocular discomfort. Different intensities of ocular discomfort were measured for veterinary care products. The SMI model was considered as a reproducible and adaptable evaluation method for screening veterinary care products causing ocular discomfort.
Subject(s)
Eye/drug effects , Hair Preparations/toxicity , Irritants/toxicity , Mucous Membrane/drug effects , Animals , Gastropoda , Toxicity Tests/methodsABSTRACT
BACKGROUND: The "hair strand test" was first developed as a model to evaluate the antifungal activity of antidandruff shampoos. OBJECTIVE: To assess the residual activity of an antifungal shampoo on the hair shafts of dogs after a single application, followed by bathing with a physiological shampoo one month later. ANIMALS: Six beagles (two males and four females) from a research colony. METHODS: Dogs were bathed with a 2% climbazole shampoo. Hairs were collected before application of the shampoo and at scheduled intervals for 30 days after treatment. A physiological shampoo was then applied to all dogs and hairs were collected following the same schedule. The inhibition zone around the hair shafts was measured after incubation on Sabouraud's dextrose agar plates streaked with three Malassezia pachydermatis strains. RESULTS: Inhibition zones around hairs collected from dogs bathed with 2% climbazole shampoo were significantly larger than those around hairs collected before shampooing at all time points (P = 0.003). An increase in the width of the inhibition zones around climbazole treated hairs was observed following physiological shampoo on Day 30 (P = 0.005). No significant differences were observed between Malassezia pachydermatis isolates (P = 0.571). No inhibition zones were seen around the hairs of dogs bathed with physiological shampoo only. CONCLUSIONS: The modified hair strand test is useful for the assessment of residual antifungal activity on animal hairs. Use of a physiological shampoo following antifungal shampoo therapy may increase the efficacy of the antifungal product for the control of Malassezia overgrowth.
Subject(s)
Antifungal Agents/pharmacology , Hair/chemistry , Imidazoles/pharmacology , Animals , Antifungal Agents/chemistry , Dogs , Female , Hair Preparations/chemistry , Imidazoles/chemistry , Malassezia/drug effects , MaleABSTRACT
BACKGROUND: Wipes containing chlorhexidine and azole derivates have been recommended for veterinary use. No study has been published about their activity against Malassezia pachydermatis. HYPOTHESIS/OBJECTIVES: To evaluate the in vivo and in vitro activity of wipes soaked in a chlorhexidine, climbazole and Tris-EDTA solution against Malassezia pachydermatis. ANIMALS: Five research colony shar-pei dogs. METHODS: Wipes were applied once daily onto the left axilla, left groin and perianal area (protocol A), and twice daily on the right axilla, right groin and umbilical region (protocol B) for 3 days. In vivo activity was evaluated by quantifying Malassezia colonies through contact plates on the selected body areas before and after wipe application. The activity of the solution in which the wipes were soaked was assessed in vitro by contact tests following the European Standard UNI EN 1275 guidelines. RESULTS: Samples collected after wipe application showed a significant and rapid reduction of Malassezia yeast CFU. No significant difference in the Malassezia reduction was found between protocols A and B. In vitro assay showed 100% activity against Malassezia yeasts after a 15 min contact time with the wipe solution. CONCLUSIONS AND CLINICAL IMPORTANCE: Wipes containing chlorhexidine, climbazole and Tris-EDTA substantially reduced the M. pachydermatis population on the skin of dogs. The results, although this was an uncontrolled study performed on a small number of dogs, suggest that these wipes may be useful for topical therapy of Malassezia dermatitis involving the lips, paws, perianal area and skin folds.