Purity: Shrouding with Animal Hides, Wool, or Fur

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 569:

It is not permitted to shroud a corpse with the hide of an impure carcass when other options are available. Similarly, based on obligatory precaution, shrouding with the hide of a pure carcass and with cloth made of the wool or fur of an animal whose meat is unlawful to eat is also not permitted when there are other options available. However, there is no problem if the kafan is made of the fur or wool of an animal whose meat is lawful to eat, although the recommended precaution is that a corpse should not be shrouded with either of these.

-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)