Garlic Is Good

I've been sharing some of my recipes on other sites and one of the comments that keeps coming up is "Garlic will kill a dog!" I strongly beg to differ and Kirby, at a healthy active five years of age, can back me up!   However, I'm not basing my decision to utilize garlic in my recipes based on flavor and aroma (which is amazing by the way!) but on the research efforts of experts who are proving that garlic is actually good for dogs.  


The Controversy

Many sources believe that garlic is toxic to dogs and it should never be used in dog food or dog treats.  There are more than 51,000 sites devoted to warning about the "toxicity" of garlic even though there is little scientific data to back this claim other than the fact that thiosulphate is also found in garlic. 

ASPCA warns “All close members of the onion family (shallots, onions, garlic, scallions, etc.) contain compounds that can damage dogs’ red blood cells if ingested in sufficient quantities. A rule of thumb is “the stronger it is, the more toxic it is.” Garlic tends to be more toxic than onions, on an ounce-for-ounce basis. While it’s uncommon for dogs to eat enough raw onions and garlic to cause serious problems, exposure to concentrated forms of onion or garlic, such as dehydrated onions, onion soup mix or garlic powder, may put dogs at risk of toxicosis. The damage to the red blood cells caused by onions and garlic generally doesn’t become apparent until three to five days after a dog eats these vegetables. Affected dogs may seem weak or reluctant to move, or they may appear to tire easily after mild exercise. Their urine may be orange-tinged to dark red in color. These dogs should be examined by a veterinarian immediately. In severe cases, blood transfusions may be needed.”

Sounds pretty convincing until you realize there are more than 400,000 sites proclaiming its benefits, many of them from reputable holistic veterinarians who have widely used garlic in their practice for many years.

A Shared Common Substance

Both garlic and onion contain thiosulphate, the substance responsible for causing ‘Heinz Factor’ anemia in dogs and cats.  Garlic simply DOES NOT CONTAIN THE SAME CONCENTRATION of this compound! In fact, it is barely traceable and readily excreted (not stored in the body).

The Family Tree

Garlic comes from the Allium family which counts onions, leeks, chives, and shallots as relatives. Onions, and to a lesser degree garlic, contains a compound called n-propyldisulfide, a compound that can cause oxidative damage to red blood cells when taken in large enough doses. The effect creates Heinz bodies which the body will reject from the bloodstream. After injecting large amounts over a long period of time, it can lead to anemia and even death.

The History

It all started over 100 years ago when wild onions (in the same family of garlic) were fed to cattle, sheep, and horses which showed toxicity symptoms. In the 1930s, studies showed that dogs who ate onions showed toxicity symptoms. In the 1980s, cats that ate onions exhibited the same toxicity symptoms as dogs did. It’s important to note that cats are six to eight times more sensitive to onion than dogs.

Garlic really got a bad rap in 2000 when a research paper was published based on garlic’s effect on dogs. Even though the dogs tested didn’t show any outward appearance of toxicity symptoms, there was an effect on the red blood cells. The researchers stated: “We believe that foods containing garlic should be avoided for use in dogs.” This was when garlic was touted as a poison for dogs and started to be removed from dog foods.

Medicinal Ingredients

Garlic contains multiple sulphur-inclusive compounds.  Allinn and another enzyme ‘alliinase’, both present in garlic but contained in separate cells, gain the opportunity to combine and create a new enzyme called ‘allicin’ when garlic is chopped, crushed, minced or chewed. Allicin (an anti-biotic, anti-bacterial, anti-cancer, heart healthy enzyme) is the most beneficial of the healthful enzymes in garlic.

Activating The Medicinal Properties

Use fresh garlic whenever possible and prepare by chopping, crushing, mincing or pressing/bruising the fresh garlic. For optimum health benefits, let the garlic sit for 5 to 10 minutes after cutting and before serving or cooking.  This gives the allinn and alliinase sufficient time to undergo the enzymic reaction that creates allicin, the medicinal ingredient in garlic.

Dehydrated, powdered garlic, or preserved minced garlic intended for culinary use has been degraded from processing and it's medicinal qualities are lost hence it's only remaining purpose is to please the palate. Fresh, refrigerated preserved garlic that has been kept refrigerated after the initial curing period will have beneficial probiotic properties but may not have the other medicinal qualities offered by fresh garlic.

Safe Dosages

Too much of anything is bad for you. Even vitamins and minerals that you assume make your dog healthy can be detrimental in large daily amounts. It’s even been proven recently that too much water can kill you! The same goes with garlic and dogs. At some level, everything has the potential to be toxic.

Gregory Tilford, (author of All You Ever Wanted to Know About Herbs for Pets) states dogs can quite safely consume 1/8 teaspoon of garlic powder per pound of food 3 to 4 times a week.

Dr. Martin Goldstein (author of The Nature of Animal Healing) recommends adding garlic to home-made pet food and feeds garlic to his own cats and dogs on a regular basis.

Dr. Pitcairn (author of The Complete Guide to Natural Health for Dogs and Cats) recommends the following amount of fresh garlic for dogs, according to their size:

  • 10 to 15 pounds - half a clove
  • 20 to 40 pounds - 1 clove
  • 45 to 70 pounds - 2 cloves
  • 75 to 90 pounds - 2 and a half cloves
  • 100 pounds and over - 3 cloves

Dr. Messonnier (author of The Natural Vet's Guide to Preventing and Treating Cancer in Dogs) recommends one clove of fresh garlic per 10 to 30 pounds of weight a day to boost the immune system and cancer prevention.

The Whole Dog Journal recommends garlic as a good addition to any raw diet. Their advice is that you can safely feed 1 clove of garlic for every 20 lbs of body weight.

As with most herbs, at least one to two days off per week or a periodic week off from garlic is a good idea.

Benefits Of Garlic

The reason why garlic is added to dog food and treats is because it has many health benefits. Even if you’re not sure about dogs and garlic, and decide to start with a very low amount, your dog will still reap the healthy rewards.

Garlic is a powerful, natural broad-spectrum antibiotic. Garlic is also an antioxidant, anti-allergen, antibacterial, anti-fungal, anti-protozoan, anti-viral and anti-carcinogen. 

Garlic has proven to do wonders with dogs with suppressed immune systems and as well has those fighting cancer. It gives a boost to bloodstream cells that kill bad microbes and cancer cells.

Garlic is known to have detoxifying effects which can help the liver get rid of toxins from the body.

Garlic has potent antimicrobial and antibiotic properties it uses to fight parasites and protozoan organisms as well. Bacteria, virus and fungi are no match for garlic.

The proper dose of uncooked garlic can help lower blood cholesterol and triglyceride levels.

Garlic can help older and overweight dogs because it can prevent blood clots and reduce cholesterol levels and fat build up in the arteries.

Garlic contains germanium, an anti-cancer agent and an anti-protozoan. Garlic also 1contains sulfur, a natural insect repellent.

Garlic helps to prevent a variety of cancers such as bladder cancer, colon cancer, prostate cancer, lung cancer, rectal cancer, and stomach cancer. It is also used to treat some forms of cancer such as bladder and prostate cancer.

Garlic is high in vitamins, minerals and nutrients like Calcium, Potassium, Zinc, Vitamin A, B, B2, and C.

Garlic is an aid to fighting and treating asthma, environmental allergies, diabetes, diarrhea, fatigue, and the maintenance of healthy liver function.


When used in the dosage provided above, garlic is safe for pregnant dogs. The only caution for pregnant dogs is that if ingested in large quantities it can flavor the milk of lactating females.

Don't give garlic to puppies that are 6 months of age or younger.

Some garlic from China has been found to be contaminated with high levels of arsenic, lead and added sulfites.

Garlic is high in insoluble fiber and sulfur compounds so as a general rule it is best not to give fresh garlic to dogs that have IBS or colitis.

Drug Interactions

Check with your veterinarian if your dog is on any medications. Garlic may increase the rate at which cyclosprine is broken down by the body so it might decrease its effectiveness, and can slow down blood clotting which would affect the efficacy of a blood thinner.

Home Remedies

Garlic is a natural dewormer which can be used in combination with other herbs and nutraceuticals to treat, repel and avoid the development of parasite infestations.

It’s a natural insect repellant and can also be used topically in combination with other herbs and nutraceuaticals to treat and repel insects. Keep in mind that the garlic secretes into the skin (no, your dog won’t smell like garlic) and washing with a sudsy shampoo removes its effectiveness.  

Fresh garlic can fight infections of the mouth, throat, respiratory tract, stomach, or intestines.

Crushed garlic diluted in olive oil can be used as a topical antiseptic for minor injuries, ear infections, or ear mites.

An ear medicine is crush 2 cloves fresh garlic, wait ten minutes, then add to 1/3 cup olive oil. Heat in a pan (do NOT boil) for several minutes. Let cool. Strain and store in a glass bottle with a dropper and apply it directly in the ears.

Garlic Tips

To get rid of the smell on your hands, rinse them under water while rubbing them with a stainless steel bar or spoon.


Sources: Dr. Pitcairn’s Complete Guide to Natural Health for Dogs and Cats, The Whole Dog JournalAlternative Medicine for,,,,,,