Answered by: Maulana Muhammad Asadullah Anwar Adam
It is not permissible to hurt or injure or slaughter an animal without reason. But with a valid reason, permissible.
In the name of Allah, the Most Gracious, the Most Merciful
Allah (SWA) has enjoined kindness in all things, as it says in the hadith:
“Verily Allah is kind and He loves kindness and confers upon kindness which he does not confer upon severity and does not confer upon anything else besides it” 
Furthermore, the is a hadith that mention severe punishment for mistreating an animal.
Ibn Umar RA narrated: the Prophet (ﷺ) said, “A woman entered the (Hell) Fire because of a cat which she had tied, neither giving it food nor setting it free to eat from the vermin of the earth. ” 
It is not permissible to cause undue pain on an animal, even when slaughtering as mentioned in the hadith: “Verily Allah has prescribed Ihsan (proficiency, perfection) in all things. So if you kill then kill well; and if you slaughter, then slaughter well. Let each one of you sharpen his blade and let him spare suffering to the animal he slaughters.” 
Only Allah knows best
Written by Maulana Muhammad Asadullah Anwar Adam
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
 Sahih Muslim Hadith 2593
 Sahih al Bukhari Hadith 3318
 40 Hadith An Nawawi