“… and Toxic”

Horses and other equids, like any other species, can be exposed to a variety of toxic substances. The true incidence of poisoning is difficult to estimate, and cases are likely underreported because there is no centralized mandatory reporting mechanism for poisoning in veterinary species. Such estimates rely on cases reported to poison control centers (eg, Pet Poison Helpline and ASPCA Animal Poison Control Center) or presented to referral hospitals. Underreporting is likely more severe in equines than in small animals, because equine practitioners and owners are less likely to call a poison control center than small animal practitioners and owners.
Source: Veterinary Clinics of North America: Equine Practice - Category: Veterinary Research Authors: Tags: Preface Source Type: research