Suspected hemolytic anemia secondary to acute zinc toxicity after ingestion of "max strength" (zinc oxide) diaper rash cream.

OBJECTIVE: To describe the clinical presentation of a dog with hemolytic anemia secondary to zinc toxicosis after 1-week use of "max strength" 40% diaper rash cream. CASE SUMMARY: A 2-year-old female neutered Maltese presented for vomiting, lethargy, pigmenturia, and pale mucous membranes. "Max Strength" zinc oxide cream had been applied to the patient daily for a week prior to presentation. Clinical examination revealed light pink to pale mucous membranes and tachycardia. Hematology demonstrated large numbers of spherocytes and a strongly regenerative anemia. Plasma zinc concentrations were markedly increased. A diagnosis of hemolytic anemia secondary to subacute zinc toxicosis was made and supportive therapy was instigated. The patient ultimately recovered uneventfully. Acute or subacute zinc toxicosis resulting in hemolytic anemia is not frequently observed, and this case was also unusual in that the zinc source was diaper cream, which historically has been thought to require very large quantities to cause toxicosis. NEW OR UNIQUE INFORMATION PROVIDED: To the authors' knowledge, there is only one previously reported case of hemolytic anemia secondary to diaper cream use in a hospital setting but no previous reports involving toxicosis secondary to prolonged application at home by owners. Most commercial diaper creams contain zinc oxide, which historically was thought to have poor gastrointestinal absorption and would require a large quantity to cause significant toxicosis and hemolytic anemia. Moreover, this case emphasizes the potential risks associated with zinc oxide cream use, the significance of client education if using these creams, as well as the importance of history in elucidating the underlying cause of hemolytic anemia.

The use of therapeutic plasma exchange to reduce serum bilirubin in a dog with kernicterus.

OBJECTIVE: To describe the use of a manual method of therapeutic plasma exchange to reduce total serum bilirubin, manage kernicterus, and halt progression of neurological dysfunction in a dog with immune-mediated hemolytic anemia (IMHA). CASE SUMMARY: A 5-year-old male neutered Lhasa Apso diagnosed with IMHA developed acute onset neurologic signs consistent with kernicterus. Manual therapeutic plasma exchange was performed in an attempt to reduce total serum bilirubin. The initial exchange was performed at a lower plasma exchange volume due to the dog's critical status and the dog's clinical signs progressed. More aggressive plasma exchange was performed that resulted in a reduction in total serum bilirubin and no further progression of neurologic signs. The dog was euthanized due to suspicion of permanent neurologic changes and need for further blood transfusions. Histopathology postmortem confirmed a diagnosis of kernicterus. NEW OR UNIQUE INFORMATION PROVIDED: Kernicterus secondary to hyperbilirubinemia is well described in people, but has rarely been reported in dogs. Therapeutic plasma exchange has been used for decades in people to rapidly decrease serum bilirubin when hyperbilirubinemia progresses to neurologic signs, but to the authors' knowledge this has not been described in a dog.