What is the ruling on praying on the hide of livestock?

Legally, livestock (An'am) refers to camels, cattle, and sheep. There is no objection to praying on the hide of an animal from livestock that has been ritually slaughtered. As for praying on the hide of a dead animal from livestock after it has been tanned, scholars have differed on this matter: The Malikis and Hanbalis hold that the hide of a carcass does not become pure through tanning, while the Shafi'is consider it purified by tanning, with the exception of pig and dog hides. The Hanafis also consider it purified, with the exception of pig and human hides. Some scholars are of the opinion that tanning purifies all hides of carcasses.