It’s a common myth that dogs and cats can’t have garlic. This is another topic where the internet is full of misinformation. The assumption is that since garlic is part of the onion family, that they are also toxic. This then prompts panicked pet owners to call the veterinary hospital thinking they’ve just poisoned their pet when a slice of garlic bread goes missing. I’m here to tell you, don’t panic. It’s fine.
But what makes an onion toxic to pets? Onions, leeks, chives, and garlic all contain thiosulfate. Thiosulfate toxicity leads to hemolytic amenia and even death. What most people don’t know, is that garlic contains 1/15th the amount of thiosulfate as onions. So, unless your pet consumes a huge bowl of garlic cloves, it’s really not a problem.
The Study
In 2000, there was a study from Hokkaido University that gave four dogs 1.25ml/kg body weight of garlic extract for 7 days. This concentrated form was equivalent to 5 grams of garlic cloves per kg. One large garlic clove typically weighs 4-7 grams. I’ll do the math for you. This means a 50 pound dog was fed the equivalent to 25 cloves of garlic and there were no obvious toxicity symptoms. The study did find mild changes in red blood cells, but no anemia was caused. Other studies have been conducted since and the previous warnings against garlic for pets has been retracted.
In fact, many pet foods contain garlic and have for decades. You just need to look at your ingredient label. Google any pet food company and you can see their ingredient lists online as well.
Cats
A teaspoon or less of onion can be toxic to cats. Studies have shown that just 5 grams per kg body weight can cause toxicity.
Unfortunately cats are often neglected in studies, so there isn’t much known about garlic and cats. Experts suggest 1/8 – 1/4 clove of garlic is perfectly safe for your cat.
Dogs
When it comes to onions, 15-30 grams per kg body weight can cause hematologic changes in dogs. In other words, if your small dog consumes one small onion, you need to call the emergency room. Concentrated forms of onion are even worse. So avoid giving your pets any foods that may contain onion powder; such as pizza, pasta sauce, baby foods, etc. On occasion, your veterinarian may recommend you grab some meat baby food for a sick animal. Be sure to read the label! Do not use any baby foods that contain onion, onion extract, or onion powder.
Studies have proven garlic to be quite safe for dogs. Avoid giving your dog multiple cloves of garlic per day and he’ll be just fine.
**If you suspect your pet has ingested onions in any form, call the Pet Poison Helpline at 855-289-0358 and head to your local animal emergency room.