The Truth about Garlic for Dogs

The Truth about Garlic for Dogs

There is a lot of conflicting information out there on the benefits / danger of garlic for dogs.  We know how scary it can be when you see a post on social media telling you that an item can hurt your pup. The problem is that there is a lot of misinformation out there – especially on this topic!

After reviewing all of the research here’s our conclusion: YES, it is perfectly okay to feed your dog small amounts of garlic.  There are even health benefits!

The key is to never feed them excessive quantities of garlic. This is good advice for many things - example - you can die from drinking too much water.  No one is likely to do that - but it is possible…

The Science:

This may be more information that you were looking for, but here is more info (both on why some say garlic is not good for dogs, and what others believe the health benefits are):

The main controversy surrounding the safety of garlic on dogs (and cats) is a compound found in garlic (and, in greater amount, in onion) called n-propyldisulfide.

This compound can, in large doses, cause oxidative damage to red blood cells, creating Heinz bodies and triggering the body to reject these cells from the bloodstream.

If large doses of this compound are ingested on a regular basis, the process can lead to Heinz-body anemia and even death.

Does that mean garlic is harmful or toxic to dogs? Not quite!

Actually, it is hard to find clinical evidence that garlic is bad for dogs.

In 2000, a study at Hokkaido University was done in which four dogs were each given 1.25 ml of garlic extract per kg of body weight for seven straight days.

So... if the dog weighed 50 pounds, he would have been given somewhere around 25 large raw garlic cloves! (Honestly, no one in their right mind would give so much garlic to their dogs in REAL LIFE, right?)

Now, in that study, even with the ridiculously excessive amount of garlic given, none of the four dogs showed any signs of toxicity. And while the garlic did affect the dogs' red blood cells, none of the dogs developed anemia.

In fact, in a 2004 study conducted by some of the same researchers who worked on the 2000 study, it was shown that the compound allicin was good for health, and that despite the high concentrations of garlic used during the study, no development of hemolytic anemia was found in the dogs.

This 2004 study has led the researchers to retract their earlier suggestion that garlic is bad for dogs. They even concluded that this herb has "the potential to promote immune functions and prevent cardiovascular diseases."

The bottom line? Use common sense!

The key to safe use of garlic for dogs is the dosage level and frequency of use. As shown in the 2000 study, for a dog to develop abnormality in his red blood cells, he would have to eat A LOT of garlic to even begin the oxidative process. 

A healthy 50-pound dog may have to eat a whole 5-oz onion, or over 20 cloves of garlic, to start the Heinz-body process. Since red blood cells are constantly regenerated from the bone marrow, a dog would likely need to ingest this much amount of onion or garlic on a repeated basis to cause permanent harm.

On the Health Benefits of Garlic for Dogs:

Garlic has been used for thousands of years in Chinese and Ayurvedic medicine. It contains at least 30 compounds that have been found to be useful for a variety of conditions from skin disorders to cancer.

Holistic veterinarians have been recommending garlic for many years for its multiple health benefits.

Below are the main health benefits of garlic for dogs:

  • Boosting the Immune System: Garlic stimulates immune functions in the bloodstream by increasing the activities of killer cells (cells that seek out and destroy invading microbes and cancer cells).  So, it's safe to say that garlic is beneficial for dogs with suppressed immune systems and dogs fighting cancer. Moderate garlic supplementation in the diets of even healthy dogs can boost their immunity and prevent cancer.
  • Fighting Bacterial/Viral/Fungal Infections: Garlic is a powerful antimicrobial and antibiotic and is effective in fighting various forms of internal or external bacterial, viral, or fungal infection, including parasites (e.g. tapeworms) and protozoan organisms (e.g. giardia).  Fresh garlic fed as part of a dog's diet 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.
  • Enhancing Liver Function: Garlic has detoxifying effects. At least six compounds contained in garlic can enhance liver function by helping the liver to eliminate toxins from the body, thereby preventing toxic accumulation that may lead to cancerous growths.
  • Lowering Blood Cholesterol and Triglyceride Levels: Uncooked garlic mixed in with food helps to lower blood cholesterol and triglyceride levels in dogs, making it useful for certain breeds (e.g. miniature schnauzers, beagles) that are predisposed to hyperlipidemia, a condition in which the amount of fats (lipids) in the blood are elevated. 
  • Cardiovascular Tonic: A compound in garlic is effective at preventing blood clot formation in the vascular system. It can also reduce cholesterol levels and fat buildup in the arteries (atheorsclerosis). Therefore, it is an excellent cardiovascular tonic for older dogs.
  • Tick/Flea Repellent: The exact reason and extent of garlic's effect on tick and flea prevention is not clear.  It may be due to the odor released through the dog's skin as the compounds in garlic are metabolized. Whatever the reason, there are a lot of anecdotal reports on the effectiveness of garlic (especially in combination with brewer's yeast) as a tick/flea repellent.

If you’ve read all this way – wow!  We geek out on this stuff and love to dig into the science. Hope this helped put your mind at ease. I know I feel better 😊