Association of maximum voluntary dietary intake of freeze-dried garlic with Heinz body anemia in horses.

OBJECTIVE: To characterize hematologic and clinical consequences of chronic dietary consumption of freeze-dried garlic at maximum voluntary intake in horses. ANIMALS: 4 healthy sex- and age-matched horses. PROCEDURE: An initial garlic dose (0.05 g/kg, twice daily) was fed to 2 horses in a molasses carrier as part of their normal ration and was gradually increased to maximum voluntary intake (0.25 g/kg, twice daily) over 41 days. Dietary supplementation then continued for a total of 71 days. Two control horses were fed molasses with no garlic with their ration. Blood samples were collected weekly and analyzed for hematologic and biochemical changes, including the presence of Heinz bodies. Recovery of affected blood values was followed for 5 weeks after termination of dietary supplementation with garlic. RESULTS: At a daily dose of > 0.2 g/kg, horses fed garlic developed hematologic and biochemical indications of Heinz body anemia, as characterized by increases in Heinz body score (HBS), mean corpuscular volume (MCV), mean corpuscular hemoglobin, platelet count, and serum unconjugated and total bilirubin concentrations and decreases in RBC count, blood hemoglobin concentration, mean corpuscular hemoglobin concentration, and serum haptoglobin concentration. Recovery from anemia was largely complete within 5 weeks after termination of dietary supplementation with garlic. Heinz body score and MCV remained high at the end of the 5-week recovery period. CONCLUSIONS AND CLINICAL RELEVANCE: Horses will voluntarily consume sufficient quantities of garlic to cause Heinz body anemia. The potential for garlic toxicosis exists when horses are chronically fed garlic. Further study is required to determine the safe dietary dose of garlic in horses.

Nervonic acid is transferred from the maternal diet to milk and tissues of suckling rat pups.

Three experiments were designed to investigate the metabolism of dietary nervonic acid (24:1n-9, NA) during reproduction in the rat. The first experiment determined the effect of early development on the sphingomyelin (SM) composition of rat heart and liver tissues. Rats were fed a standard chow diet and the SM fatty acid composition of the hearts and livers were analyzed of 18-20 day old fetuses, 14 day old sucklings and adult rats. The 18:0 content of SM decreases with age, while 23:0 and iso 24:0 increase with age. In the second experiment pregnant rats were fed diets supplemented with either canola, corn or peanut oil to determine the effect of diets high in 24:1n-9 and 24:0 on liver and heart SM at birth and after 14 days of suckling. Pups from the dams fed the corn oil diet had elevated 24:2n-6 in SM from heart and liver at birth, but the content of NA was not altered by dietary fat type. In the third experiment oil mixtures were designed to provide elevated levels of 22:1 and 24:1 (canola-N25), 22:0 and 24:0 (peanut-flax) or <0.01% of these fatty acids (olive-flax) and were supplemented to the diets of lactating rats. Canola-N25 oil supplemented to lactating rats resulted in increased 24:1n-9 and 24:1/24:0 with decreased 22:0 and 24:0 in milk SM relative to the other groups. The SM composition of livers of the suckling rats showed significant changes reflecting the changes in milk SM composition after 6 days of milk consumption. These experiments suggest that dietary NA and is not readily transferred across the placental barrier but does readily cross the mammary epithelium and is incorporated into milk SM. In addition, NA in milk appears to cross the intestinal epithelium where it is incorporated into the SM of heart and liver of suckling rats.