Salam
This last year I undertook some studies of hanbali fiqh of worship via listening to recorded lessons, reading with a teacher in Kuwait over skype and corresponding with teachers in Saudi Arabia regarding specific issues. Coming from a hanafi background it has been a breath of fresh air for me, and teaching the rules of purification from a primer on hanbali fiqh did help to consolidate what I had learned. InshAllah from time to time I will be posting some answers here relating to the hanbali school and any details of any recorded lessons.
Cat Food in the Hanbali School
A question was asked regarding the purchase of pet food containing haram meat to feed a cat. The answer below is based on a response provided by Shaykh Salih al-Asmari (a learned Athari Hanbali scholar based in Saudi Arabia):
There are two aspects to this question:
First: the sale transaction of something which is classified as impure such as pork, the madhab position is that this sale transaction is not permitted.
Second: the use of something regarded as impure in sacred law or haram meat to feed a cat, there are two opinions mentioned in al-Furu (6/272), namely the permissibility and impermissibility of doing so.
Wassalam
Saleh