Allium species toxicosis most commonly occurs after oral consumption. In addition to consuming fresh plant material, consuming juice, fresh and aged dietary supplements, powdered cooking preparations, dehydrated material, or food preparations derived from or containing Allium species can be potentially toxic to dogs and cats.1 Allium species toxicosis typically ensues after consumption of a single large quantity of the material or repeated small amounts. Dogs and cats are highly susceptible to onion toxicosis: Consumption of as little as 5 g/kg of onions in cats or 15 to 30 g/kg in dogs has resulted in clinically important hematologic changes. Onion toxicosis is consistently noted in animals that ingest more than 0.5% of their body weight in onions at one time.
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