Published: June 3, 2022  

Last updated: February 6, 2024  

Author: Debi McKee

There is so much conflicting information on the internet about garlic and dogs. One study says garlic is extremely toxic to dogs. Another study will say garlic can be healthy for dogs.

So, which is it? Is garlic toxic or is garlic healthy? The truth is garlic is BOTH toxic and healthy.

Eating or drinking anything, even water can be toxic to humans and dogs. Moderation is key to all foods.

Garlic can be poisonous to dogs in large quantities. But most experts agree that it is unlikely that your dog will ingest enough garlic to be toxic.

It’s my opinion that if you feed the appropriate amounts, garlic is completely safe and even healthy for your dog. (Keep reading for a few exceptions.)

IMPORTANT: Make sure to consult your vet before feeding your dog garlic, especially if your dog has a health condition, such as pancreatitis.

dog and garlic gloves

Garlic in dog food

Would it surprise you to learn that many top dog food brands such as Purina, Blue Buffalo, Wellness, and others all have some form of garlic in their ingredient list? Don’t believe me, check it out all the dog foods with garlic for yourself.

And if you search for dog treats, you will find garlic in Milk Bones, Pup-Peroni, Purina, and more.

If garlic is so toxic to dogs, why would Purina put it in their dog food?

Why are there 639 results if I search Chewy for garlic?

Remember this as you read on about garlic poisoning in dogs and the contradicting studies found below.

This video below with Dr. Karen Shaw Becker and Rodney Habib (The Forever Dog) very informative and helps clarify the facts about garlic and dogs.

“What stood out to me in the very beginning, “What’s the difference between a nutrient, a drug, and a toxin? The answer, the dosage.”

Garlic poisoning in dogs

Garlic is classified as a species of the Allium family (onion, garlic, scallion, shallot, leek, and chives).

The Allium family contains compounds called disulfides and thiosulphates which can be toxic to dogs if ingested in large amounts.

These compounds can cause a breakdown of red blood cells, leading to anemia in dogs.

According to this PubMed article, “Garlic (Allium sativum) is considered to be less toxic and safe for dogs than onion when used in moderation.”

Your dog would need to consume an obnoxious amount of garlic to become toxic.

Clinical studies on garlic and dogs

The first study that suggested garlic is toxic to dogs was performed by a group of scientists, including Osamy Yamto, in the year 2000. The study included a mere 8 dogs and used a crazy high dosage of garlic extract.

Here is an excerpt of this study:

Hematologic changes associated with the appearance of eccentrocytes after intragastric administration of garlic extract to dogs

Procedure: 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 7 days. The remaining 4 control dogs received water instead of garlic extract.

Results: Compared with initial values, erythrocyte count, Hct, and hemoglobin concentration decreased to a minimum value on days 9 to 11 in dogs given garlic extract. Heinz body formation, an increase in erythrocyte-reduced glutathione concentration, and eccentrocytes were also detected in these dogs. However, no dog developed hemolytic anemia.

Conclusions and clinical relevance: The constituents of garlic have the potential to oxidize erythrocyte membranes and hemoglobin, inducing hemolysis associated with the appearance of eccentrocytes in dogs. Thus, foods containing garlic should not be fed to dogs. Eccentrocytosis appears to be a major diagnostic feature of garlic-induced hemolysis in dogs.

In simple terms, a 50 pound dog would be given about 25 large raw garlic cloves a day (245 gloves per week)! Crazy, right? No dog would ever eat that much garlic.


Osamy Yamto performed another study in 2004 that concluded dogs given garlic can “promote immune functions and prevent cardiovascular diseases”.


Then in 2018, another study by Osamy Yamto concluded garlic “might safely contribute to the health of dogs provided that the appropriate dosage is used.”


A retrospective study of 60 cases of eccentrocytosis in the dog

This study states that “Eccentrocytes have been reported rarely in dogs and are associated with onion and garlic ingestion and the administration of oxidant drugs.” And “11 (18.3%) with presumptive onion and garlic ingestion”

Note: Eccentrocytes are red cells with a ragged appearing, poorly hemoglobinized fringe of cytoplasm along one side of the cell. Source.


Safety and efficacy of aged garlic extract in dogs

This study, Safety and efficacy of aged garlic extract in dogs, concluded: “The long-term oral administration of AGE at a dose of 90 mg/kg/day for 12 weeks did not show any adverse effects in dogs. Furthermore, the administration of AGE upregulated the gene expressions of canine Nrf2 and Nrf2-regulated phase II antioxidant enzymes. These results suggest that AGE might safely contribute to the health of dogs provided that the appropriate dosage is used.”


Allium spp Toxicosis in Animals

This is the newest (June 2021) clinical information I could find in the Merck Manual Veterinary Manual.

“Allium spp toxicosis is characterized by development of hemolytic anemia after ingestion of large amounts of plant material. Toxicosis has been reported in livestock after feeding of onions, and dogs and cats have been affected after ingesting cooked, dehydrated, or granulated forms of onions or garlic. Several days after ingestion, clinical signs of acute hemolytic anemia develop, including weakness, pallor, icterus, and collapse.”

Sharon Gwaltney-Brant DVM, also states that “Garlic is 3–5 times more toxic than onion.”

Which is the exact opposite of what was cited in the PubMed article.


Each study and professional article contradict the other. The information is so conflicting the average dog parent can’t know if garlic is truly a toxin for their dog.

garlic bulb and cloves

Symptoms of garlic poisoning in dogs

If your dog ate a large amount of garlic and you are concerned, call your vet right away.

Clinical signs of garlic toxicity may show up between 24 hours up to 1 week after ingesting.

Pet Poison Helpline lists garlic as a moderate toxicity level and recommends watching for these common signs of garlic poisoning:

  • Anemia (e.g. lethargy)
  • Pale gums
  • Increased heart rate
  • Increased respiratory rate
  • Weakness
  • Intolerance to exercise (e.g. collapsing)
  • GI upset (e.g., nausea, drooling, abdominal pain, vomiting, diarrhea)

Dog breeds that are more sensitive to thiosulfates

Remember, thiosulfates are the chemical compound found in onions and garlic that is thought to be toxic to dogs. Some dog breeds were found to be more sensitive to thiosulfates:

  • Japanese and Korean breeds
  • Shibu Inus
  • Akitas
  • Jindos
  • Japanese Chin

If you have a dog with a pre-existing health condition you should talk with your holistic veterinarian before giving them any new supplements, including garlic.

Benefits of garlic for dogs

Some benefits of giving garlic to your dog include:

  • Decreases blood pressure
  • Controls blood glucose levels
  • Great for heart health/cardiovascular system
  • Boost immune system
  • Can reduce tumor incidence from mycotoxins
  • Assists in repelling fleas and ticks

Fresh garlic vs. garlic supplements

According to Dr. Karen Shaw Becker, “The difference between real, fresh garlic and garlic pills, powders, and extracts is that real garlic contains the enzyme alliinase, an enzyme that must be present to spark the biochemical reactions that unlock the medicinal compounds in this potent health food.”

Fresh garlic is always best. But if you’re like me, I don’t have time to cut fresh garlic every day for my three dogs, although after this research I may try to add fresh garlic once a week. Right now, I opt for Brewers Yeast & Garlic Chewable Tablets as part of our natural flea and tick repellent regimen.  

How much garlic to feed your dog

I found two reliable sources in how much garlic your dog should be eating.

Dr. Karen Becker recommends the following doses of fresh garlic per day. (The Forever Dog, Page 246)

Size of DogAmount of Fresh Garlic Per Day
10 to 15 lbs1/2 clove
20 to 40 lbs1 clove
45 to 70 lbs1-1/2 cloves
75 – 90 lbs2 cloves
100 lbs and over2-1/2 cloves

According to Dogs Naturally Magazine, you should feed your dog the following dosage of fresh garlic. I’m not sure why they only go up to a 30 pound dog, so you’ll need to do some math if you have a larger dog.

Size of DogAmount of Fresh Garlic
5 lbs1/6 tsp
10 lbs1/3 tsp
15 lbs1/2 tsp
20 lbs2/3 tsp
30 lbs1 tsp

For maximum health benefits, chop fresh garlic and let it sit for 10 to 15 minutes before adding it to your dog’s food. Exposing garlic to air releases allicin, the substance that provides garlic’s many health benefits.

Garlic and dogs: my conclusion

After all this research, I have concluded garlic is healthy for most dogs in the correct dosage. I found no evidence of dogs dying from eating garlic. And I was not surprised that most holistic vets agree that garlic is a great supplement for dogs, and most traditional vets will tell you garlic is toxic to your dog.

IMPORTANT: Make sure to consult your vet before feeding your dog garlic, especially if your dog has a health condition, such as pancreatitis.

It’s up to you, as your dog’s parent, to make the right decision. I’ve given you all the research and facts… will you start or continue to give your dog fresh garlic or a garlic supplement?

For the past several years I’ve given my three dogs the garlic tabs during flea and tick season. I believe it has helped in our repertoire of flea and tick prevention.

You may decide the risks outweigh the health benefits or vice versa. And that’s totally okay, do what is right for you and your dog.

References

Because the facts are important when it comes to your dog’s health, here are links to everything I have referenced in this article about dogs and garlic.

What’s Next?

About the Author

Debi McKee

Debi McKee is the expert behind Rescue Dogs 101 where she guides you in your journey of adopting and raising a rescue dog every step of the way. She is a mom of 3 human kids and 4 dogs and volunteers for a local dog rescue and Humane Society. Click here for more about Debi and her passion for helping you and your dog.

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