If in doubt, always call your vet or the Animal Poison Line immediately.
Hops (Humulus lupulus) used in beer brewing cause a condition called malignant hyperthermia in dogs. Body temperature can spike to fatal levels very rapidly. Both fresh and dried hops are dangerous. Greyhounds and sighthound breeds appear especially susceptible.
Treat as an emergency. Cool your dog with wet towels and seek immediate veterinary care.