The pH of the tooth surface was determined in cats with neck lesions. The presumption that commercial dry cat food with an acid coating can lead to neck lesions is investigated. In general cats with neck lesions had lower pH values of the tooth surface (7.93 +/- 0.61) than healthy cats (8.65 +/- 0.58). Feeding dry cat food with an acid surface did not contribute to the pathogenesis of neck lesions.