The fruit of the hops plant (humulus lupulus) is commonly used in the production of beer. In fact, the number of hops cases at the APCC doubled from 2014 to 2015 and has been steadily rising ever since.
When dogs ingest hops the consequences can be disastrous, including malignant hyperthermia and death. Any dog with an exposure to brewing hops (fresh, pellet or spent) is at risk of developing malignant hyperthermia and should be closely monitored for at least 12 hours.
While the onset of clinical signs can be very rapid—within the first 30-60 minutes—in some cases it may take up to 12 hours post exposure. Signs following ingestion include panting, hyperthermia, vomiting, restlessness, agitation, tachycardia, injected mucous membranes, tremors, seizures and death.
If you have a patient who has been recently exposed to hops, emesis can be induced if the pet is asymptomatic. Activated charcoal may be of benefit, but the pet should be carefully monitored for hypernatremia after administration.
A warm water enema may be very helpful in removing plant material from the GI tract and can be safely administered in symptomatic animals.
Careful monitoring of body temperature is indicated in dogs who have ingested hops. Diagnostics such as serum chemistry, creatine kinase, coagulation profile and urinalysis may be indicated.
Dogs with hyperthermia should be monitored for disseminated intravascular coagulation and rhabdomyolysis. Treatment consists of aggressive intravenous fluids, external cooling, methocarbamol, anti-epileptics, cyproheptadine and dantrolene.
Signs can last 24-48 hours and the prognosis is guarded in symptomatic animals, especially if treatment is delayed.