We have recently had a letter published in The Journal of Veterinary Emergency and Critical Care, discussing our experience with hops toxicosis in dogs.
We published an abstract on 13 cases in 2019, and since then we have had 6 additional cases with outcome information. One dog remained well after ingestion of spent hops, one dog only had gastrointestinal signs after ingestion of plant material, 3 recovered, and one died following ingestion of spent hops. In 2 cases spent hops had been spread on the garden as fertilizer, including the fatal case. This dog, a 22kg Labrador, presented 3 hours after it had vomited hops material, with tachycardia, panting and pyrexia. Hops were retrieved from the stomach on gastric lavage, and despite active cooling the body temperature continued to rise. Four hours after onset of signs the temperature was 42.7C and the dog had a cardiopulmonary arrest. Resuscitation attempts were unsuccessful.
Discarded hops in compost or used as fertilizer appear to be particularly attractive to dogs. Much remains unknown about the toxic mechanism of hops in dogs and prompt and aggressive treatment is essential. Once malignant hyperthermia starts there may be rapid deterioration and irreversible organ damage.