Dogs (Canis lupus familiaris) should if possible avoid hops (Humulus lupulus). For dogs ingesting hops can, and often do, overheat to an alarming, sometimes life-threatening degree. *see note. The physiological pathways involved are as yet
poorly understood unknown. See: Toxicology Brief: Hops Make Dogs Hot, Veterinary Technician, August 2013 (Vol 34, No 8).
Improbable has tried to find research regarding spontaneous combustion amongst canines, with very little, if any, success.
Photo credit: The picture, via Wikipedia, shows a healthy Whippet, a breed of Sighthound, which it seems are particularly susceptible.