Contribution of propylene glycol-induced Heinz body formation to anemia in cats.
Propylene glycol (PG) is a common preservative and source of synthetic carbohydrates in soft-moist pet foods. Propylene glycol was fed to cats for 5 weeks at concentrations found in commercial diets (1.6 g/kg of body weight; 12% of diet on a dry-weight basis) and for 3 weeks at concentrations exceeding usual intake (8 g/kg; 41% of diet). There was a dose-dependent increase in Heinz body percentage to 28% in cats fed the low dose of PG and to 92% in cats fed the high dose. Erythrocyte half-life, measured using [14C]-cyanate hemoglobin (Hb), decreased significantly (P less than 0.05) by 18.8% and 60% in cats fed the low and high PG doses, respectively. The PCV in cats fed the low dose was unaffected, whereas cats fed the high dose had a mean (+/- SEM) decrease in PCV from 33.5 +/- 1.05% to 26.3 +/- 1.45%, accompanied by punctate reticulocytosis and bone marrow erythroid hyperplasia. A dose-dependent increase in iron pigment was found in the liver and spleen of all cats. In cats fed the low dose of PG, erythrocyte reduced glutathione concentration actually increased from 7.02 +/- 0.56 to 9.74 +/- 0.69 mumol/g of Hb, but decreased to 2.96 +/- 0.27 mumol/g of Hb in cats fed the high dose. There was no significant increase in methemoglobin concentration. These results indicated that PG cannot be considered innocuous even at concentrations consumed by cats eating commercial diets. Heinz body-induced acceleration of RBC destruction develops in a dose-dependent manner, so that cats with greater food intake, ie, lactating queens and nursing kittens, are at greater risk for development of PG-induced Heinz body hemolytic anemia.
Christopher
M M
MM
Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Minnesota, St Paul 55108.
Perman
V
V
Eaton
J W
JW
D000743:Anemia, Hemolytic / Q000139:chemically induced / Q000662:veterinary*; D000821:Animal Feed / Q000009:adverse effects*; D000818:Animals; D001853:Bone Marrow / Q000187:drug effects; D002371:Cat Diseases / Q000139:chemically induced*; D002415:Cats; D004305:Dose-Response Relationship, Drug; D004905:Erythrocyte Aging / Q000187:drug effects; D005260:Female; D006366:Heinz Bodies / Q000502:physiology*; D006400:Hematocrit / Q000662:veterinary; D006454:Hemoglobins / Q000032:analysis; D008099:Liver / Q000187:drug effects; D008297:Male; D008706:Methemoglobin / Q000032:analysis; D019946:Propylene Glycol; D011409:Propylene Glycols / Q000633:toxicity*; D012156:Reticulocytes / Q000187:drug effects; D013154:Spleen / Q000187:drug effects
D006454:Hemoglobins; D011409:Propylene Glycols; D019946:Propylene Glycol; D008706:Methemoglobin