Objective: To describe the clinical signs and outcomes observed after Humulus lupulus (hops) ingestion in dogs. A secondary objective was to note any trends in the number of hops-related phone calls made to an animal poison control center over a 13-year period.
Design: Retrospective study (2005-2018).
Setting: An animal poison control center.
Animals: One hundred and seventy-seven dogs with known or suspected hops ingestion.
Interventions: None.
Measurements and main results: A total of 177 calls were made to Pet Poison Helpline between 2005 and 2018 involving hops ingestion in dogs. Outcomes were determined in 83 cases; 79 of 83 (95.2%) survived. Clinical signs associated with hops ingestion were observed in 74.0% (131/177). Commonly observed clinical signs were tachypnea (98/131), hyperthermia (65/131), and vomiting (44/131). Severe hyperthermia (>41.4°C, [>106°F]) developed in 8 dogs and 3 of those dogs did not survive. A fourth nonsurvivor was found deceased at home. The majority of symptomatic dogs developed clinical signs between 2 and 8 hours postingestion. Resolution of clinical signs occurred in less than 24 hours in all survivors except in one. Cases consulted with Pet Poison Helpline related to hops ingestion increased from 2005 to 2018 relative to the total amount of cases managed overall.
Conclusions: The most common clinical signs associated with hops ingestion include tachypnea, hyperthermia, and vomiting; however, not all dogs develop clinical signs. While prognosis is good with 95.2% of dogs in this population surviving, some dogs can develop a severe and fatal hyperthermia.
Keywords: Anatomy, Plant toxicology; Anesthesiology; Intoxication; Malignant hyperthermia; Toxicology; Toxicology, Diagnosis.
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