Dogs and pigs, and all of their body parts are najis. Therefore, their leather is also najis.

The grand maraje’ state: Dogs and pigs that live on land are najis, including their hair, bones, paws, nails, and any wetness they excrete.[1]

For further information on the rulings regarding dogs, refer to the following questions: 2827 (website: 3055), 1305 (website: 1291), 3430 (website: 4155). For information on different types of leather, see: Question 451 (website: 484).