If the animal has been slaughtered properly, then it is permissible to use its horn. If the animal is still alive or it dies without being slaughtered in the prescribed manner, then there is a difference of scholarly opinion as to whether it is pure or not. For more, see the detailed answer.

1- Keeping dogs in Islam is not permissible except for hunting or guarding livestock and crops. 2- It is permissible to keep dogs for guarding houses so long as that is outside the city and that there is no other means of guarding the house. 3- The Muslim should not imitate others by running with the dog or touching its mouth and kissing it, which causes many diseases.

It is not permissible for Muslims to use gold and silver as vessels, whether for eating or drinking. The same applies to things used for Wudu and Ghusl.