Hawzah News Agency – When using leather shoes, the leather for which was made from an animal that was not ritually slaughtered, is it obligatory to wash one’s feet every time before performing wuḍū’? Some say: It is necessary to do so if the feet perspire in the shoes. And I have observed that the feet do sweat, either slightly or profusely, in all kinds of shoes. What is your opinion on this issue?

Answer: If a person is sure that his shoes are made of an animal’s skin which was not slaughtered ritually or he is sure that his feet have perspired in such shoes, it is obligatory for him to wash his feet for the purpose of praying. But in case of doubt about the sweating of the feet or whether or not that leather is obtained from a ritually slaughtered animal, the feet are ruled to be pure.

Source: https://www.leader.ir/en/book/32/Practical-Laws-of-Islam