Answered by Sidi Omar Mahmood
Regarding the hukm of cat hair.
as salamu alaykum wa rahmatullah,
Bismillah ar-rahman ar-rahim
The ulama say that a separated piece of an animal has the same hukm (ruling) as a dead version of that animal. For example, since a fish is always tahir (clean) no matter how you kill it, the broken off piece of a live fish (like a fin) is also considered tahir. In the case of a cat, which is not an animal we eat, killing a cat will result in the dead body being najas (impure). Likewise, cutting off the paw of a live cat will result in that paw being najas similarly the separated hair of a cat (also najas).
Animal hair can be broken down as follows:
-hair still connected to any animal (other than dog or pig) is considered tahir.
-hair separated from animals we eat is considered tahir
-hair separated from animals we do not eat is considered najas
to remove cat hair that is najas, you simply remove the hair from the clothing or place
It should be noted here that in the Hashiyat al-Baajuriy, in the sharh on the matn of Abi Shuja`, Shaykh Baajuriy indicates that the ulama have allowed for small amounts of separated hairs from animals other than dogs or pigs. For example, many people have pet cats, and because of the hardship in removing all the hairs of the cat from one’s clothing/floor … small amounts of scattered strands of hair that are not readily apparent are considered ma`fu `anhu (forgiven amounts) … and with animals that humans generally use for labor or as riding animals, even a lot of strands of hair are considered forgiven.
wa Allahu a`lam
forgive me,
wassalaam
-Omar