Yes.
And so is necrophilia.
Believe it or not, it's true.
Sunan Abu Dawud 38:4450
Narrated Abdullah ibn Abbas: There is no prescribed punishment for one who has sexual intercourse with an animal.
Sahih Muslim - Book of Menstruation - hadith #525
Our companions have said that if the penile head has penetrated a woman's anus, or a man's anus, or an animal's vagina or its anus then it is necessary to wash whether the one being penetrated is alive or dead, young or old, whether it was done intentionally or absentmindedly, whether it was done willfully or forcefully.
If a woman inserts (in her vagina) an animal's penis she must wash, and if she inserts a detached penis (thakaran maktu-an, lit. “a severed male member”) there are two opinions; the most correct is that she must wash.
Sex with animals Fatwa - al-Uzma Seyyid Ali al-Sistani
Sex with animals before the mission (Islam) was wide spread and many narrations are narrated that it is halal but makrooh (disliked). And on the compulsory precaution one should abandon this practice that may cause self harm. And you must admit this to the owner of the sheep and pay the owner.
Allamah Hassan bin Mansoor Qadhi Khan, Fatawa Qadhi Khan, Page 820
"Sex with animals, dead people and masturbation, does not invalidate one's fast provided ejaculation does not occur"
Abu Bakar al-Kashani (d. 587 H), Badaye al-Sanae, Vol. 2, p. 216
"If he had sexual intercourse with an animal, that will not make his hajj void"