“Dogs also acquire lymphoma. One recent study showed that pet dogs living in households whose lawns were treated with 2,4-D [a phenoxy herbicide] were significantly more likely to be diagnosed with canine lymphoma than dogs whose owners did not use weed killers. Risk rose with number of applications: the incidence of lymphoma doubled among pet dogs whose owners applied lawn chemicals at least four times per year. A study of people, however, found no excess lymphoma among those exposed to residential pesticides.”
Steingraber, Sandra. Living Downstream: An Ecologist’s Personal Investigation of Cancer and the Environment (pp. 56). Da Capo Press. Kindle Edition.