The dog's saliva is Najis (ritually impure), so the vessel or garment tainted with it must be washed out. The Prophet (peace be upon him) said:
If a dog licks the vessel of any of you, it should be washed seven times; the first time with dust.
If the clothes are put into pure water and washed until the traces of Najasah (ritual impurity) are removed, they will all be cleansed of dog's Najasah or any other dirt, provided that they are washed seven times; the first time with dust or what replaces it, such as soap or potash.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.