Toxicity of Garlic and Onions

The question came up on the list, whether garlic and onions were toxic to dogs. After a short debate, one of the members decided to ask Dr. Diana Beam, DVM, Team Member of Ask The Vet, and and her response was the following:

RE: Onions, her response was: “Onions can be very toxic to dogs. They cause oxidative damage to the hemoglobin resulting in an acute anemia depending on the amount of intake. Fresh or cooked onions can be toxic. If enough is ingested, it can even result in the need for a blood transfusion. Hemaglobin can be passed in the urine as well and if your dog is not kept well hydrated the kidneys can be damaged as well. Known ingestion of onions is considered an emergency and depending on how long since the ingestion determines what treatments are required. A dog's stomach empties fairly quickly so the induction of vomiting is not always an effective way to stop the toxicity.

RE Garlic, she said: “Yes, garlic can be toxic as well, usually it is used in a lesser amounts in cooking, etc. hence this is postulated to be the reason we do not see it as much. If it were my dog, I would not use it. ”

The Holistic Dog interprets the last paragraph as meaning that you probably should not attempt to feed your dog a whole clove of garlic at one time, but rather in the quantities you use for seasoning a single person's dinner. Proportion and quantity, again, often makes the difference between medicinal importance and poison.

Please NOTE that the ASPCA also lists garlic under their toxic foods list.


From the ASPCA Animal Poison Control Center :

Foods to Avoid Feeding Your Pet

- Alcoholic beverages
- Avocado
- Chocolate (all forms)
- Coffee (all forms)
- Fatty foods
- Macadamia nuts
- Moldy or spoiled foods
- Onions, onion powder
- Raisins and grapes
- Salt
- Yeast dough
- Garlic
- Products sweetened with xylitol

Warm Weather Hazards 
- Animal toxins—toads, insects, spiders, snakes and scorpions
- Blue-green algae in ponds
- Citronella candles
- Cocoa mulch
- Compost piles Fertilizers
- Flea products
- Outdoor plants and plant bulbs
- Swimming-pool treatment supplies
- Fly baits containing methomyl
- Slug and snail baits containing metaldehyde

Common examples of human medications that can be potentially lethal to pets, even in small doses, include:
- Pain killers
- Cold medicines
- Anti-cancer drugs
- Antidepressants
- Vitamins
- Diet Pills

Cold Weather Hazards
- Antifreeze
- Liquid potpourri
- Ice melting products
- Rat and mouse bait

Common Household Hazards
- Fabric softener sheets
- Mothballs
- Post-1982 pennies (due to high concentration of zinc)

Holiday Hazards 
- Christmas tree water (may contain fertilizers and bacteria, which, if ingested, can upset the stomach.
- Electrical cords
- Ribbons or tinsel (can become lodged in the intestines and cause intestinal obstruction—most often occurs with kittens!)
- Batteries
- Glass ornaments

Non-toxic Substances for Dogs and Cats 
The following substances are considered to be non-toxic, although they may cause mild gastrointestinal upset in some animals:
- Water-based paints
- Toilet bowl water
- Silica gel
- Poinsettia
- Cat litter
- Glue traps
- Glow jewelry