Edmund R. Dorosz, BSA, DVM
My Dad did not like onions. He could detect the slightest hint of onion in anything my mother prepared. He could detect the use of the same knife that cut onions and later was used to cut some other food. " Gophers and grasshoppers don't eat onions. " I can remember him saying many times at the dinner table.Gophers and grasshoppers maybe know something that we are just starting to learn about this bulb that we all grow in our gardens and eat in salads and with liver. My father excluded.
It is known that onions cause Heinz body hemolytic anemia in dogs, cats, sheep, cattle and horses. Onions contain, oxidative chemicals such as n-propyl disulfide, that oxidize the animal's red blood cells. Once the red blood cells have been subjected to this oxidation and destruction the appearance of Heinz bodies, named after a German pathologist Robert Heinz, show up in the animals blood.
Red blood cells contain hemogloblin that transports oxygen from the animal's lungs to the rest of the body's cells and returns carbon dioxide back to the lungs to be exhaled. Then the cycle is repeated.
A decrease in the numbers of red blood cells in the blood decreases the ability for the blood to carry oxygen. This decrease is called anemia. Signs that we would see in our animals would be pale mucous membranes, listlessness, decreased activity, an increased respiratory rate and possible death especially in young, old or chronically sick individuals.
It is due to this destructive nature of onions on the oxygen carrying ability of the red blood cells that we do not feed onions to our domestic animals. We do not feed fresh or cooked as cooking does not alter the oxidative effects on the red blood cells.
So dad was right in his observation that gophers and grasshoppers don't eat onions. They must have figured this out a long time ago.
 NetPets® Main Page | Main Library Healthspa Nutrition |  The Dog Center |