General:
* Yelling
* Screaming
* Shouting
* Roaring
* Wailing
* Crying (especially for animals)
* Barking (for dogs)
* Meowing (for cats)
More specific:
* Baying (for hounds)
* Howling at the moon (specifically for wolves)
* Screaming in agony
* Singing in pain
Figurative:
* Lamenting
* Mourning
* Crying out
The best synonym depends on the specific situation and the type of sound you want to describe.