Does washing pet food bowls remove Microsporum canis fungus?

Abstract

BACKGROUND: Dermatophyte lesions are common on the face of animals and pet food bowls can become contaminated by direct contact with the facial lesions. Owners are concerned about appropriate decontamination and yet worried about exposing pets to disinfectant residues. OBJECTIVE: To determine the efficacy of mechanical cleaning alone for decontamination of contaminated pet food dishes. METHODS AND MATERIALS: An isolated infective spore suspension of Microsporum canis was used to experimentally contaminate metal (n = 4), plastic (n = 4) and glass (n = 4) pet food bowls. The experiment was repeated twice, first with just the spore suspension, and then with a mixture of spore suspension and canned pet food. The bowls were soaked in hot water (34°C) with a generic dish soap in a sink for two minutes, scrubbed using a dishwashing brush until visibly clean or for 2 min, rinsed, allowed to air-dry and then cultured. Fungal culture samples were collected using disposable dust cloths. Environmental fungal cultures were obtained from the sink after routine mechanical cleaning with a sudsy detergent. RESULTS: No environmental contamination was detected. The results of both experiments were similar. All bowls (n = 24) were fungal culture positive for M. canis before washing and all were completely decontaminated with mechanical washing alone. CONCLUSIONS AND CLINICAL IMPORTANCE: Mechanical washing alone can decontaminate pet food bowls exposed to naturally infective material. Dishes should be soaked in hot sudsy water to loosen organic debris, scrubbed until visibly clean and then rinsed. Owners should wear dishwashing gloves for personal protection.