Among the ingredients, we discourage our pet parents here to avoid is garlic extracts. Garlic extracts including garlic oil are considered to be healthy supplements with a lot of commercial pet food manufacturers adding them with some of the claimed benefits being;
- Keeps pets’ hearts healthy
- Assist in pests control
- Helpful in digestion as an antioxidant.
Let’s start with the basics though.
What is garlic?
The garlic plant is a member of the onion genus and its latin name is Allium sativum. It is closely related to onions, chives, shallots, and leeks and its species is those of bulbous flowering plants.
It has been used as both a food flavoring and medicinal herb for centuries dating back to the Ancient Egyptians.
Garlic extracts are a concentrated form of the garlic plant and are made by soaking garlic cloves in ethanol or vinegar. The extract is then dried to form a powder that can be used as a seasoning.
Garlic oil is made by pressing garlic cloves to extract the oil. The oil is then used as a flavoring or as a base for other flavors.
Garlic Nutritional Profile:
I use data from nutritionvalue.org and info from the USDA database with detailed info on raw and extracted garlic.
The USDA Foundation data that nutritionvalue.org used to calculate caloric profile of garlic produced the charts below.
As shown, 100-gram portion of garlic has the following nutrients;
- Carbs make up 78%,
- Fat makes up 2% and
- Protein makes up the remaining 20%
Below are other nutrients that garlic and garlic extracts including garlic oil have.
According to USDA data, a 100 gram portion of garlic contains;
- 10 mg of Vitamin C
- 9.80 mcg of Selenium
- 6.62 grams of protein
- 25.5 grams of carbohydrates
- 2.7 grams of fiber
- 0.38 grams of fat
- 63.1 grams of water
- 1.06 grams of nitrogen
- 181 mg of calcium
- 25 mg of Magnesium, Mg
- 153 mg of Phosphorus, P
- 401 mg of Potassium, K
- 1.16mg of Zinc
On the USDA database, there are few other trace minerals that you can read more here.
Let’s take a closer look at the nutrients by explaining dog’s use of each nutrient.
Vitamin C is an important nutrient for dogs as it helps to maintain a healthy immune system, skin and connective tissue.
Selenium is a trace mineral that plays an important role in the metabolism and has been shown to have anti-cancer properties.
Protein is an essential nutrient for all animals and is used by the body for growth, repair and maintenance.
Carbohydrates are an important source of energy for dogs and are needed for growth, reproduction and many other body functions.
Fiber is an important nutrient for dogs as it helps to maintain a healthy digestive system.
Fat is an essential nutrient for dogs and is needed for the absorption of fat-soluble vitamins, insulation, and energy production.
Water is an essential nutrient for all animals and is needed for the proper functioning of all body systems.
Nitrogen is an important nutrient for dogs as it is a key component of proteins, which are needed for growth, repair and maintenance.
Calcium is an important mineral for dogs as it is needed for the development and maintenance of strong bones and teeth.
Magnesium is an important mineral for dogs as it is needed for the proper functioning of many enzymes, including those involved in energy production.
Phosphorus is an important mineral for dogs as it is needed for the development and maintenance of strong bones and teeth.
Potassium is an important mineral for dogs as it is needed for the proper functioning of many body systems, including the nervous system and the heart.
Zinc is an important mineral for dogs as it is needed for the proper functioning of many enzymes, including those involved in wound healing and immunity.
As you can see, garlic is a nutrient-dense food that can provide many health benefits to dogs. Garlic is a good source of vitamins, minerals, and antioxidants that can help to boost the immune system, promote healthy skin and coat, and support overall health.
Case for Garlic in Dog Food
The health benefits of garlic are well-documented. Garlic has been shown to boost the immune system, promote healthy skin and coat, and support overall health.
Garlic is a good source of vitamins, minerals, and antioxidants that can help to boost the immune system.
In addition, garlic has been shown to have anti-cancer properties.
Dr. Khalsa makes the case for garlic as a safe dog food ingredient:
Dr. Deva Khalsa made the case for garlic in dog food explaining the nutritional benefits and refuting the studies that garlic can be harmful to dogs. She claims that for garlic to be harmful, you’d have to be feeding 75 to 150 cloves of garlic a day.
On average a bulb of garlic contains 10 to 12 cloves that make up the garlic head.
Below is an image of garlic head and garlic glove;
Dr. Khalsa who has over 30 years as pet nutrition scient goes on to use the anecdote that even drinking too much water by humans can be fatal but water is totally safe and can’t just stop drinking water because it can be harmful to our health in high amounts.
Dr. Khalsa also revealed that the National Animal Supplements Council has reported that over 900 million garlic doses have been given to dogs over the years and no reported cases of having adverse effects on dogs.
They kill bacteria and unlike synthetic drugs used to fight bacteria in a dog’s gut, bacteria do not become resistant to garlic.
Dr. Khalsa also discusses the benefits of Allicin, an active medicinal nutrient in garlic that has anti-cancer, antiviral and antioxidant properties. With 1 in 2 dogs dying of cancer in the US, she insists that garlic shouldn’t be considered harmful and should in fact be an essential ingredient.
Below is a full video of Dr. Khalsa making the case for garlic in dog food:
So, who else is for garlic in dog food?
The San Franscisco Raw Feeders Association (SFRAW) wrote a blog in July 2019 formally explaining the case for feeding garlic to dogs and cats but were very clear that they should be given in moderation.
Below is a snapshot of the blog from their article which is available here.
In the blog, they also emphasize the need to rotate your pet’s diet include varying herbs such as garlic and ginger.
“Remember that regularly rotating and varying herbs and seasonal foods, such as garlic and ginger, is essential to their conscientious use, providing nutritional balance, synergistic healing and strengthening effects of these wonderful foods.” – SFRAW
For pets with sensitive stomachs, they explained that it’s better to slowly introduce any commercial pet food with these herbs slowly as monitor any negative reactions, dislike, food intolerances or allergies
National Research Council Report in 2008 on Garlic’s safety in Dog and Cat food:
The National Research Council which was started back in early 1900s made the case in a 2008 report that garlic is safe for dogs when given in moderation. NRC is a US non-profit responsible for providing independent, objective advice to the US government on scientific and technical matters. AAFCO also follows their recommendation on nutrients to recommend to manufacturers of pet food.
The report specifically look at use of garlic as a supplement and this was their conclusion;
““garlic has a long history of safe use as a supplement, with mean levels of 22 mg/kg BW being reported without serious adverse events “
The report acknowledge limitation of data to use to determine the optimal amounts and specifically the safe upper limits to give to dogs and cat. It recommended that historical safe intakes (HSI) and presumed safe intakes (PSI) which are estimates be used in determining the amounts.
Presumed safe intake for dogs is 56 mg per kg of dog’s body weight but the mean levels of 22 mg per kg of body weight were reported to have no adverse impacts on dogs.
The report cited insufficient data for cats as well and made a general recommendation that 17 miligrams per kg of cat’s body weight are ideal as such mean levels have been found to have no adverse effects.
FDA approved it as a safe pet food ingredient but has now classified as poisonous:
The FDA has approved garlic as a safe ingredient to be added in pet food but in 2014, the ASPCA’s poison hotline was full of pet parents reporting alleged cases of dog poisoning from garlic. As of 2022, FDA has now listed garlic in its database of poisonous plants.
The case against Garlic in dog food:
It leads to Heinz body formation:
Heinz bodies are damaged red blood cells. When these damaged cells circulate through the body, they can cause anemia. Anemia is a condition in which there are not enough healthy red blood cells to carry oxygen to the tissues. Heinz bodies are named after Dr. Robert Heinz, who first described them in the early 1900s.
This study found that 75-pound Golden Retrievers that received 5 heads of garlic, had their red blood cells getting damaged. 5 heads of garlic is equivalent to more than 50 garlic gloves in each meal which is super high amount.
This is the main reason why this report has been refuted by the likes of Dr. Khalsa who claim that 50+ gloves of garlic is such an high amount to feed any dog and in normal circumstances, no one feeds garlic to their dogs in such proportions. She noted that the report shouldn’t have made a blanket recommendation backing up critics who claim that it is dangerous.
They can cause Heinz body anemia:
A few studies have tried to make the connection that the damanged red blood cells in dogs as a result of garlic consumption may lead to anemia but the studies did give data on the number of dogs affected. In other words, there are no reported cases of garlic being directly linked to anaemia in dogs but following the study that found Heinz body formations, it was easier to associate that it could potentially lead to anaemia. Symptoms of Heinz body anemia can include weakness, lethargy, and pale gums.
They can cause gastrointestinal upset:
Some dogs may experience gastrointestinal upset when they eat garlic. The San Frascisco Raw Food Associaion also mentioned that some dogs may have difficulty adjusting to new herbs, especially those with sensitive stomachs. This, however, does not mean garlic is bad for your dog as it may take a few days or weeks for some dogs to get adjusted to them.
Symptoms of gastrointestinal upset can include vomiting, diarrhea, and abdominal pain. If your dog experiences these symptoms after eating garlic, it is important to contact your veterinarian.
Now considered poisonous by credible organizations:
Despite FDA’s intial approval of garlic as a safe pet food ingredient, it has now listed it as a poisonous ingredient. Earlier this year, FDA decommissioned the site listing garlic as a poisonous ingredient after not updating the database since 2008.
ASPCA has also listed garlic as toxic to dogs.
Below is a snapshot of the ASPCA listing as a toxic ingredient. Read more here
In a 2-year period, the ASPCA Animal Poison Control Center case record database for garlic exposure revealed 23 cases (20 dogs, 3 cats). Only 6 of the 20 dog had clinical signs of garlic toxicity.
Pet Poison Helpline:
Pet Poison Helpline has also indicated that garlic is 5 times more toxic than onions.
Below is a snapshot from their website listing it as a toxic ingredient to avoid. Read more on their website here.
How much garlic to feed dogs:
The general rule of thumb is 1 clove of garlic per 20 to 40 pounds of body weight. You can also use garlic powder, which is about 1/8 teaspoon per 10 to 20 pounds of body weight.
If you dog is under 20 pounds, give no more than half a clove and if it is a big dog weighting over 40 pounds, give it 2 cloves.
When introducing garlic to your dog’s diet, start with a small amount and increase gradually over a period of several weeks. This will give your dog time to adjust to the new flavor and minimize the risk of gastrointestinal upset.
Below are some more specific amounts to feed your dog with different weights from Juliette de Bairacli Levy’s book;
- 10 to 15 pounds – ½ clove
- 20 to 40 pounds – 1 clove
- 45 to 70 pounds – 2 cloves
- 75 to 90 pounds – 2½ cloves
- 100 pounds and over – 3 cloves
Preparing garlic for dog to eat:
A dog can eat raw garlic or in powder form.
- Chop the garlic cloves into small pieces. Add the garlic to your dog’s food and mix it well.
- Wait for at least 20 mins after chopping before feeding to allow the allicin (a compound in garlic) to form. Allicin is the active ingredient in garlic that has many of the health benefits.
- For powder, you can add it directly to your dog’s food.
Why we avoid recommending Garlic and Garlic oil as an ingredient in dog foog:
We are following the recommendations of credible organizations:
ASPCA and other credible organizations have conclusively made the case that all dogs are susceptible to garlic toxicity. 2-year review of data from ASPCA found that 20 dogs had indeed been poisoned by garlic.
Aside from ASPCA, Pet Poison Hotline and FDA have also acknowledged garlic as poisonous to pets.
As the NRC report indicated that more research needs to be done to determine full extent of garlic toxicity, we would rather than our readers not expose their pets to garlic.
It is important to avoid garlic if your dog has G6PD deficiency:
Another study found that all dogs,especially those with G6PD deficiency are susceptible to garlic toxicity.
G6PD deficiency is found in dogs with a genetic disorder and lower G6PD results in a dog increases its risk of oxidative injury from garlic ingestion. Unless you have checked with your vet and are sure that your dog does not have G6PD deficiency, you can feed your dog garlic but only in small amount. Aside from ASPCA, Pet Poison Helpline has also listed it as toxic to pets and FDA has also listed it as a poisonous plant.
Dogs with High Concentration of Erythrocyte GSH can potentially die from Garlic:
A 1992 Study on “Susceptibility to onion-induced hemolysis in dogs” by Yamamoto and Maede found that dogs with high levels(five to seven times normal) of erythrocyte GSH are more susceptive to oxidation induced by onions. Given that onions are 5 times more toxic than garlic and they are in the same family, I would avoid giving my dog garlic unless I am 100% sure that it doesn’t have high levels of erythrocyte GSH.
Japanese breeds such as Akitas and Shiba Inus are known to have this conditions and should avoid giving garlic to these breeds.
Garlic grown in regions with high concentration of disulfide are more toxic:
Garlic toxicity in pets is dictated by the concentration of disulfide which is high if the garlic was grown in regions with high sulfur concentration. In the US some states with high concentrations are Louisiana, Texas, Colorado, Nevada, Wyoming, and California.
Since there is no ingredient tracing requirement by the FDA or by AAFCO, it is impossible to know if garlic in any particular commercial dog food was grown in or out of the mentioned states. To be on the safe side, we just don’t recommend garlic in dog food.
How much garlic will kill my dog?
If you feed your dog 15 to 30 grams per kilogram of their body weight, it leads to structural changes in your dog’s red blood cells and continous exposure may eventually lead to death. This study concluded that pets should not ingest 0.5% of their body weight and this other study revealed that the toxicity may start showing within a day.
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Hi there! My name is Ben Domb, an owner of two pets and I am one of the co-founders of OurPets HQ. I have several years of experience as a pet care professional in the New England region having spent time in various roles including a stint at a veterinary hospital in Upstate New York, Syracuse area. I am a certified pet care professional and mostly spend my time researching pet nutrition and sharing my thoughts in various blogs and columns. With quarantine and COVID restrictions, I have been spending a lot of time a lot with my dogs and cat and loving it! I also run a small consulting business providing advice to parents on pet nutrition, and especially safe homemade options to try. You can reach me at email@example.com