HOW MUCH GARLIC IS SAFE FOR DOGS?

The Greek physician Hippocrates is quoted as saying “Let food be thy medicine, and medicine be thy food”. 2400 years ago, he was prescribing garlic as a treatment for some medical conditions. And modern science has now proven that garlic truly does have many health benefits. It contains numerous vitamins and minerals and used correctly as a supplement can help combat sickness, reduce blood pressure, lower cholesterol and much more.

So…is garlic safe for dogs? It’s time to separate fact from fiction.
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Garlic: What It Is

Garlic is part of the Allium family which also includes onions, leeks, chives, and shallots. These all contain a compound called n-propyldisulfide as well as thiosulphate. When ingested in large amounts, oxidation can occur in red blood cells resulting in what is known as “Heinz bodies” which the body rejects from the bloodstream. If large amounts of garlic are ingested over a long period, it can cause anemia and even death. But does this mean that garlic isn’t safe for dogs?
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History of Animals and Garlic

​From the early 1900’s, wild onions were fed to grazing animals (cattle, sheep, horses, etc.) and these animals showed toxicity symptoms. In the 1930’s, testing shows that dogs who ate onions showed toxicity symptoms. In the 1980’s, testing showed the same results with cats. Although onions and garlic are related, does this necessarily mean garlic produces the same toxicity symptoms?

Most of the scrutiny and negative attention surrounding dogs and garlic came when a research paper was released in 2000 by Hokkaido University. The conclusion of the study was stated as “Thus, foods containing garlic should not be fed to dogs. Eccentrocytosis appears to be a major diagnostic feature of garlic-induced hemolysis in dogs.”

But let’s not just look at their conclusion…let’s look at the study as a whole. The procedure was stated as follows: “4 dogs were given 1.25 ml of garlic extract/kg of body weight (5 g of whole garlic/kg) intragastrically once a day for seven days.” For example, a dog weighing 40 pounds would have been given 20 cloves of garlic – a huge amount! Think about the amount of garlic you would have to ingest were you part of that test. That amount of garlic would probably have a negative effect on anyone. But even with the large amounts of garlic ingested, not a single dog developed hemolytic anemia, and the conclusion was that using these amounts, garlic had the “potential” to cause hemolytic anemia.


Garlic Dosage

​Too much of anything can be bad. There are many healthy vitamins and minerals that are beneficial to both us and our fur babies but can be harmful in large daily amounts.
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An article on garlic by The American Kennel Club states, “So it is perfectly natural for us to wonder if we can feed garlic to our dogs. The answer, emphatically, is no.” They then go on to share the amount of garlic that is toxic to dogs. “Studies have found it takes approximately 15 to 30 grams of garlic per kilograms of body weight to produce harmful changes in a dog’s blood.”

Just to put these numbers into perspective, my 85 lb. Labrador Retriever would need to eat 152 cloves of garlic before it would be toxic for him.

Let’s look at the daily recommended dosage as prescribed by Dr. Pitcairn from ‘The Complete Guide to Natural Health for Dogs and Cats’:

• 10 to 15 pounds: 1/2 clove
• 15 to 40 pounds: 1 clove
• 40 to 70 pounds: 2 cloves
• 70 to 90 pounds: 2 1/2 cloves
• 100 pounds +: 3 cloves

So as you can see, the daily recommended dosage is well below what was being administered in the Hokkaido University study in 2000. It’s also important to note that the level of those dangerous compounds found in garlic simply aren’t as high as they are in other members of the Allium family. In fact, thiosulphate is barely traceable in garlic and is easily excreted. “In the testing of onions and garlic on (the dog’s) blood cell oxidation, onions have about 15 times the ability of garlic to damage red blood cells,” states nutritionist Dr. Dave Summers.


Benefits of Garlic for Dogs

​So, what exactly are all of the benefits of using garlic correctly as a supplement for your dog?

• Pest Repellant: Garlic won’t kill fleas or ticks, but the taste will deter them away from your dog.
• Improved Immune System: Garlic has helped many dogs with a suppressed immune system. It boosts blood cells that kill harmful microbes.
• Healthy Liver: Garlic has been shown to be a powerful detoxifier, helping the liver get rid of toxins from the body.
• Helps Fight Infections: Garlic has antibacterial and antimicrobial properties which makes it ideal for helping to fight viral, fungal, and bacterial infections. It can even fight off parasites.
• Cardiovascular Health: Garlic can lower cholesterol and triglyceride levels, reduce fat build-up in the arteries and prevent blood clots.

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Garlic for Your Dog…Yes or No?

A lot of the topic comes down to personal preference and research. There are many reputable resources on both sides of this issue. Speak to your vet if you’re considering adding a garlic supplement or any supplement to your dog’s diet.

What do you think? Do you feed your dog garlic with his food or as a supplement? Do you avoid garlic because you’d rather be “safe than sorry”? We’d like to hear from you. Leave your thoughts in the comments below!