Potential zinc phosphide rodenticide toxicosis in dogs: 362 cases (2004–2009)

Abstract

OBJECTIVE: To evaluate records of dogs exposed to zinc phosphide rodenticides and characterize the patient population, including breed, sex, age, body weight, time since exposure, development of clinical signs, clinical signs observed, treatments performed, veterinary care received, outcome, and overall prognosis. DESIGN: Retrospective case series. ANIMALS: 362 dogs with presumed zinc phosphide exposure. PROCEDURES: An electronic computer database from an animal poison control center was searched to identify dogs that ingested zinc phosphide between November 2004 and July 2009. RESULTS: Accurate information regarding development of clinical signs was available in 94.5% (342/362) of cases. Over half the dogs (58.8% [201/342]) did not develop clinical signs, and specific clinical signs were reported for the remaining 41.2% (141/342) of dogs. There were 180 total clinical signs recorded for these 141 dogs, with some dogs having developed > 1 category of clinical signs. Clinical signs involving the gastrointestinal tract were the most commonly reported type of clinical sign (66.7% [n = 120/180 reported signs]), followed by generalized malaise (17.8% [32/180]), CNS signs (8.9% [16/180]), respiratory signs (3.3% [6/180]), and cardiovascular signs (1.7% [3/180]). Approximately 65% (234/362) of patients received veterinary care (including decontamination via induction of emesis, gastric lavage, or activated charcoal administration), and of these dogs, 51.3% (120/234) were hospitalized. For the 296 dogs for which survival data were available, the survival rate was 98.3% (291/296). CONCLUSIONS AND CLINICAL RELEVANCE: Overall, the prognosis for zinc phosphide toxicosis was good. Zinc phosphide rodenticide toxicosis is a potential public health concern, and veterinary staff should be aware of this commonly used rodenticide.