Is it permissible to permanently declaw a cat's front paws to protect family members and furniture? And is it permissible to perform surgery on it to prevent it from reproducing in order to stop its urination for marking its territory?

Firstly: It is permissible to declaw a cat if it does not cause harm to it, and many medical methods are currently available for this.

Secondly: Preventing a cat from reproducing is preventing an innate instinct. If this procedure causes harm or complications to the cat, then it is not permissible, because the prohibition of harm is general for humans and animals. There are hadiths that forbid harming and torturing animals.

Scholars have differed in their opinions regarding the castration of non-humans: Hanafis: There is no harm in it due to its benefit for the animal and people. Malikis: It is permissible to castrate an animal whose meat is eaten without dislike, for the improvement of its meat. Shafi'is: It is permissible to castrate an animal whose meat is eaten when it is young, and forbidden otherwise, provided it does not lead to its demise. Hanbalis: Castrating sheep is permissible for improving their meat, but Imam Ahmad disliked it due to the prohibition of harming animals.

Accordingly, it is permissible to castrate a cat if there is a benefit for it and it does not lead to its demise, as Sheikh Ibn Uthaymin issued a fatwa permitting it if cats are numerous and bothersome, and they are not harmed by the procedure.