OBJECTIVE To evaluate signalment, clinical signs, dose ingested, treatment requirements, duration of hospitalization, and outcome of dogs exposed to phenylpropanolamine. DESIGN Retrospective case series. ANIMALS 170 dogs with potential PPA toxicosis evaluated between 2004 and 2009. PROCEDURES Dogs with potential PPA toxicosis were identified by reviewing the electronic database of an animal poison control center. RESULTS 66 of the 170 (39%) dogs reportedly did not develop any clinical signs. Clinical signs reported in the remaining 104 (61%) dogs included agitation (n = 40), vomiting (27), mydriasis (19), lethargy (17), tremor or twitching (16), panting (15), bradycardia (13), tachycardia (12), hypertension (11), and erythema (8). Median dose ingested for all dogs was 29 mg/kg (13.2 mg/lb). Dogs developing clinical signs had a significantly higher median dose ingested (373 mg/kg [170 mg/lb]) than did dogs that did not develop clinical signs (18 mg/kg [8.2 mg/lb]). Likewise, median dose ingested for the 123 dogs treated as inpatients (36.9 mg/kg [16.8 mg/lb]) was significantly higher than the median dose for the 14 dogs treated as outpatients (20.5 mg/kg [9.3 mg/lb]). Median duration of hospitalization was 18 hours (range, 4 to 72 hours), and hospitalization time increased as the dose ingested increased. Survival rate was 99.4% (169/170); the dog that died had ingested a dose of 145 mg/kg (65.9 mg/lb). CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that with supportive care, the prognosis for dogs that had ingested an overdose of phenylpropanolamine was excellent.