Narrated by Al-Husayn ibn Sa’id, from Safwan, from Al-‘Ala ibn Razin, from Muhammad ibn Muslim, from one of the Imams عليه السلام:
Imam عليه السلام was asked regarding a man who touches a dead animal, is ghusl required for him? Imam عليه السلام said: "No, that (requirement) applies only to (the dead body of) a human being."
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 456