in the discipline of uṣūl (legal methodology), the preferred version is Muslim’s report, which specifies that it is “the first of them.”
Scholarly disagreement
The jurists disagreed: Is a dog’s impurity confined to its mouth and saliva, or does it extend to its entire body and all its limbs?
• The majority maintained that the impurity applies to the whole animal, and that the prescribed seven washings likewise apply to anything from its body that contaminates a vessel. They reasoned by assimilating the rest of the body to the mouth.
• Imām Mālik and Dāwūd restricted the ruling to the tongue and mouth. They consider the command to wash a purely devotional act (taʿabbudī) rather than a treatment of filth; a devotional ruling, they argue, is limited to the very wording of the text and may not be extended when its underlying cause is unknown.
The first view is stronger for three reasons:
- Parts of the dog’s body are even filthier and more repugnant than its mouth and tongue.
- The default in legal rulings is that they rest on discernible causes, so the ruling is carried over to what is predominant.
- Modern research has shown that a dog’s impurity is microbial in nature; the rationale is therefore no longer hidden but plainly evident.
Al-Shāfiʿī said: “If any part of a dog—its paw, its tail, its leg, or any other limb—falls into a vessel, the contents are poured out and the vessel is washed seven times.”
Professor Ṭabbārah, in his book The Spirit of the Islamic Religion, writes: “Among Islam’s health-protective rulings is its designation of the dog as impure—a scientific miracle that anticipated modern medicine. Medicine has confirmed that dogs transmit many diseases to humans: they host a tapeworm that can pass to people and inflict serious, even life-threatening illnesses. It has been established that no breed of dog is free of these tapeworms, so dogs must be kept away from anything connected to human food or drink.”