Yes there are!!!
I personally can not give you recommendations as I do not have any pets here myself however there have been tenants in our building with pets who took them for treatment.
I know there is a vet in San Pedro de Macoris for sure.
I'll check with one of my friends here and post the info as soon as I've reached her!
Maybe someone else can check a telephone directory and post the appropriate #'s (I would but I don't get a directory as we're never here when they are distributed).