Previously I was concerned about the anemia caused by giving garlic to dogs. I have since read that the dose needed to cause that anemia is so high as to be almost impossible to reach the quantity needed to cause harm. As with most health issues, there is no simple answer to the question of feeding your dog garlic. So here are the pros and cons for you to review and make your own decision.
The Negatives About Garlic
Garlic is in the onion family. The onion in large quantities is toxic to dogs and causes the hemoglobin in red blood cells to clump together.
Those clumps, called Heinz bodies, reduce the ability of the blood to carry oxygen. It also causes a shortened lifespan of the red blood cell.
That means that more red blood cells will die than will be replaced by the body at regular intervals. That causes anemia.
While this isn’t the only way to cause Heinz bodies, it is the commonest. You can see the damaged blood cells under a microscope if methylene blue dye is used.
How fast and how damaging the anemia, depends on how much onion was consumed.
The people who swear by garlic for their dogs will insist that it does them no harm. When I give the commercial supplements, I don’t see any adverse reactions in my dogs either.
However, that doesn’t mean it isn’t harming the dog’s health just because it isn’t clinically obvious yet.
One veterinary article states that as little as 15 to 30 g/kg of onion can cause blood disorders in a dog. Garlic, being in the onion family could do the same. The poisoning can happen with a single large ingestion or small doses over time. That’s what originally put the last nail in the coffin for me.
The Positives About Using Garlic
I also found articles refuting problems using garlic.
There is one actual scientific trial I found that specified how much garlic was needed to cause the hemolytic anemia.
The dogs were intragastrically fed 1.25 ml of garlic extract/kg of body weight or (5 g of whole garlic/kg) once a day for 7 days.
That equals about 1 tablespoon of extract daily for a dog about 25 lb, or 2 oz. of fresh garlic which is about 18 average sized cloves per day.
So, as always, I think moderation in all things is going to be the key.
Historically, over 22 years and 900 million doses of garlic there have been only 2 adverse side effects reported. A safe dose for a 20lb dog would be one average sized FRESH clove, crushed or minced, daily.
Hmmmmm, much better track record than most medications prescribed to human patients. For a lot of people this is enough to give them a green light to feed their dogs garlic in order to:
- Boost the immune system
- Increase the activities of killer cells which can destroy cancer cells
- Acts as an anti-bacterial, anti-fungal, anti-viral, anti-parasitic, and anti-protozoan.
- Enhances Liver Function
- Lowers Blood Cholesterol and Triglyceride Levels
- Anticoagulant
- Tick/Flea Repellent
All of which is pretty motivating.
What Are the Active Ingredients That Make Garlic Beneficial?
There is some conflicting information regarding what the active ingredients in garlic are and how they work. (I told you this wasn’t going to be simple.)
The chemistry of garlic is quite complicated and different types of processing produce results which differ in their ingredients, effects, and toxicities. Garlic products that contain the most safe, effective, stable, and odorless components are the most valuable as dietary supplements for man or beast.
Aged Garlic Extract
According to studies of AGE (Aged Garlic Extract), this water extraction process results in greater and more consistent efficacy and safety compared with raw garlic, dehydrated garlic powder, or other preparations, with powder being the least effective. (Maybe that is why dogs fed powder have little to no side effects?)
AGE contains the compounds S-Allyl-l-cysteine, (SAC) and several nonsulfur compounds, (steroid saponins) which do provide health benefits, but no allicin.
Allicin
On the other hand, many sources say that the fresh form of crushed, minced or sliced garlic for dogs is the best. This is based on the undisputed knowledge that garlic contains both allinase, an enzyme and alliin which remain inactive until the garlic is bruised.
Once the mashing or slicing occurs there is a chemical reaction and the two components mix and create allicin. It is the allicin that many consider to be the compound that produces the wonderful benefits we have come to know and love including being a cancer killer.
Because the process is unstable, the valuable health benefits can be quickly lost. The garlic must be ingested soon after preparation (15-30 minutes seems to be the agreed upon time frame).
Just to muddy the waters, one research study determined that allicin could not be the active ingredient because it is not bioavailable when consumed. The study showed that it was not absorbed into the blood stream, that it never made it past the stomach. The acid content of the stomach neutralized any ability to be absorbed.
Finally, the cancer killing properties of allicin were only active in a petri dish but when ingested, the compound is inactivated almost immediately. They also found the allicin to be an irritant to the stomach and the compound that gave garlic its odor.
Feeding Your Dog Garlic As A Flea And Tick Preventative
I couldn’t find any studies showing the effectiveness of garlic as a flea and tick preventative for dogs either. But there are plenty of anecdotal experiences to support it.
So it’s your guess whether the smell of garlic is what discourages parasites or other components that provide the protection. There are other herbal alternatives for flea and tick control if you prefer not to start feeding your dog garlic.
When Feeding Your Dog Garlic, How Much Can You Give?
Generally speaking, 1 clove of average size per day or
1/4 tsp of the liquid per day Kyolic Garlic Formula 100, Original Cardiovascular Formula or
1 cap of 300mg AGE per day.Kyolic Garlic Formula 100, Original Cardiovascular Formula
I have to say, the more I read about the health benefits of natural foods, the more fascinated I become with the intricacies of proper preparation to keep the medicinal value of each. Don’t you ever wonder how the first people figured it out?
I mean, really, who was the first guy to pull garlic out of the ground and find out it had a use? How did he decide the many ways to try and prepare it and get some benefit from it? I certainly tip my hat to their perseverance. After all, biologists are still testing to see what it is that makes it all work.
At this point, for me, I don’t see an absolute need for garlic in my dogs’ diet as they have no issues with cancer, parasites, or other infections.