Newton Homeopathics Thuja for dogs and cats (pronounced "thoo'-yuh,") is derived from the northern white cedar, Arbor vitae, which means "Tree of Life." The primary vaccinosis (adverse reaction to a vaccination) homeopathic remedy for cats and dogs, it can be administered at any time following vaccinations. Thuja is also a safe and effective treatment for dog warts and other skin disorders, including rashes, cysts and eruptions.