Hops used in beer brewing — whether fresh, pelleted, or already spent — can be deadly to dogs regardless of form. A malignant-hyperthermia-like reaction can send body temperature above 41°C within 30-60 minutes of ingestion, though onset can be delayed up to 12 hours, so home brewers must keep hops completely out of dogs' reach. Breeds predisposed to malignant hyperthermia — Greyhounds, Labradors, Saint Bernards, Dobermans and others — are at especially high risk.