Answered by Shaykh Faraz Rabbani
Question: If a dog licks one, is it necessary to wash the area licked seven times? Does one have to use soap or any other cleaning agent? Does a dog brushing against me make my clothes filthy?
Answer: Walaikum assalam wa rahmatullahi wa barakatuh,
I pray this finds you in the best of health and spirits.
In the Hanafi school, the saliva of a dog is filthy, not its skin or hair. As such, mere ‘brushing’ of a dog against one’s clothes does not render them filthy.
If a dog’s saliva comes onto one’s clothes, one must simply wash the affected area itself, until there is no readily-removable trace of the saliva left (such as by pouring water over the affected area three times, or placing it under a running tap). Doing so seven times or with dust (or other cleaning agent) isn’t a requirement but, rather, a recommendation.[ref: al-Halabi, Multaqa al-Abhur; Shurunbulali, Maraqi al-Falah; Ibn al-Humam/Marghinani, Fath al-Qadir `ala al-Hidaya]
And Allah alone gives success.
wassalam, Faraz Rabbani