Hanyar kulawa da aka saba amfani da ita a cikin faren rana don ammar amararraki ko karnuka ko karnuka na tiyata shine amfani da ruwa mai zurfi (Treadmall Dog) . Wanda zai maye gurbin jirgin ruwa na ruwa shine cewa buoyancy na ruwa zai rage tasirin nauyi, don inganta horo ta hanyar. Za'a iya daidaita matakin ruwa bisa ga tsayin kare- kasan matakin ruwa, ƙarancin nauyi da kare yake amfani da shi. Gaskiyar ita ce a mafi yawan lokuta, karnuka suna fama da raunin da ya faru ko tiyata ba tare da amfani da ruwan sama ba kuma yanayin da suke amfani da shi ya fi wanda suke dawo da kansu. Hakanan akwai wasu fa'idodi masu yawa don amfani da treadmills, Danna don koyo.