1. A method of treating a respiratory symptom in a mammal in need of such therapy, comprising the steps of: administering a liquid composition comprising a thickening agent and a non-menthol cooling substance； and the liquid composition is brought into contact with the mucous membrane of the oral cavity of a mammal, where the liquid composition is a non-Newtonian liquid having a viscosity at zero shear from about 600 to about 1,000,000 cP at a temperature of 37 ± 1 ° C. 2. The method according to claim 1, characterized in that the thickener is selected from the group consisting of xanthan gum, cellulosic polymers, carrageenan, polyacrylic acid, crosslinked polyacrylic acid, polycarbophil, alginate, clay, and combinations thereof. The method according to claim 1, characterized in that the composition contains from about 0.01% to about 10% thickener based on the weight of the liquid composition. The method according to claim 1, characterized in that the composition contains from about 0.05% to about 5% thickener based on the weight of the liquid composition. The method according to claim 1, characterized in that the thickener is xanthan gum. The method according to claim 1, characterized in that the composition further comprises a mucoadhesive polymer selected from the group consisting of polyvinylpyrrolidone (povidone), a copolymer of methyl vinyl ether and maleic anhydride, guar gum, tragacanth gum, polydextrose, cationic polymers, poly (ethylene oxide) poly (ethylene glycol), polyvinyl alcohol, poly (acrylic acid), crosslinked polyacrylic acid, polycarbophil, poly (hydroxyethyl methacrylate), chitosan, cellulosic polymers and their combinations. 7. The method according to claim 6, characterized in that the composition contains from about 0.01% to pr1. Способ терапии респираторного симптома у млекопитающего, нуждающегося в такой терапии, включающий стадии, на которых: вводят жидкую композицию, содержащую загуститель и нементоловое холодящее вещество； и вводят в конт
