Ask the Vet: Garlic and Onions Toxic to Dogs
Q: Whenever my partner and I treat ourselves to roasted garlic on warm French bread, our dog begs for some. Is garlic safe for dogs?
A: No, so please don't let him snack on it. Garlic, onions and related vegetables are members of the genus Allium, and all are toxic to dogs.
Garlic is more toxic than onions, which are more toxic than shallots, leeks, scallions and chives. In general, the Allium species with the strongest odors and flavors are the most toxic.
These vegetables are dangerous to dogs, whether raw or cooked. Garlic powder, onion powder and other dehydrated versions are the most concentrated and therefore the most toxic.
Garlic, onions and related vegetables damage the red blood cells that carry oxygen throughout the dog's body. Several days after ingestion, the red blood cells disintegrate.
This red blood cell destruction is called hemolytic anemia. "Hemo-" is Greek for blood, and "-lytic" means to break apart. Anemia is the resulting deficiency of red blood cells.
Clinical signs may include pale pink or yellow gums, lethargy, weakness, rapid breathing and heartbeat, jaundice and red-to-brown urine.
This process doesn't occur in humans who eat garlic and onions because our red blood cells contain much more of the erythrocyte catalase enzyme that protects the cells from damage, and the human enzyme is substantially more active than the canine erythrocyte catalase enzyme.
If your dog ever does manage to wolf down some garlic or onion, contact your veterinarian immediately.
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