Garlic for dogs and cats

Garlic (scientific name Allium sativum) is a member of the onion family.
Its close relatives are: onion, shallot, leek, chive, and Chinese onion.
It was known to Ancient Egyptians, and has been used both as food flavouring and as a traditional medicine.

The composition of Garlic:
The composition of raw garlic is 59% water, 33% carbohydrates, 6% protein, 2% dietary fiber and less than 1% fat.
When expressed per 100 grams, garlic contains several nutrients in rich amounts including vitamin A, B6 and C, and the dietary minerals, manganese and phosphorous
Per 100 gram serving, garlic is also a moderate source of certain B vitamins, including thiamin and pantothenic acid, as well as the dietary minerals, calcium, iron, inulin, amino acids, sulphur, potassium, magnesium, selenium, germanium and zinc.

Garlic also contains a compound called n-propyldisulfide, as well as small amounts of thiosulphate.
When taken in large amounts, of any of these 2 compounds, oxidative damage can occur in the red blood cells, which in turn can lead to the body rejecting these cells from the bloodstream.
After ingesting large amounts over a long period of time, it can lead to anaemia and even death.

This being said we all know that consuming anything in large amounts is bad for you and your pet.
Even minerals of which you think that can make you and your pet healthy can be detrimental in large daily amounts.
Things such as salt, vitamin D, or Zinc are all good for you, as long as you’re not overdoing it.
The same goes for garlic; at some point, these things all have the potential to be toxic.

There is a lot of controversy around feeding garlic to dogs/ cats.
Maybe you are thinking “you must be mad advising to feed garlic to my pet, as onions are poisonous and you just stated that garlic is part of the onion family, in addition that garlic is more often than not put on the DO NOT FEED poison list, you may be wondering why on earth we should be feeding garlic to our dog/ cat.

Knowledge is a powerful thing and even though many shun Garlic, it ironically is an approved flavouring (spice/ seasoning) in pet food, yet the FDA lists garlic in its poisonous plant database.

Many sources believe that garlic is toxic and it should never be used in dog food.
But garlic has been used for centuries as a medicinal aid by humans, so is it true that it’s bad for dogs?

Thanks to extensive research by experts it has been found that garlic is actually good for dogs/ cats, and now they believe that garlic can benefit your pet’s health.
Of course, you can’t just throw a whole bulb of garlic at your pet, as with anything else, it’s all about the amount you give

As explained above, a compound found in in garlic (larger amounts in onions) called n-propyldisulfide 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 anaemia and even death.

Does that mean garlic is unsafe for dogs or cats?
It is hard to find evidence that garlic is bad.

In 2000, a study at Hokkaido University was done.
Four dogs were each given 1.25 ml of garlic extract per kg of body weight for seven days.
This equals to a dog that weights roughly 22.5, being fed somewhere around 25 large cloves of garlic
In that study, even with the silly 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 anaemia.

In 2004 a study performed by some of the same researchers from the 2000 study, showed that the compound allicin was good for health, and that despite the high concentrations of garlic used during the study, no development of haemolytic anaemia was found in the dogs.
This 2004 study has led the researchers to retract their earlier suggestion that garlic is bad for dogs. In fact, they concluded that this herb has “the potential to promote immune functions and prevent cardiovascular diseases.”

As shown in the 2000 study, for a dog to develop abnormalities in his red blood cells, he would have to eat A LOT of garlic to even begin the oxidative process.
A healthy 22kg dog may have to eat 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 on a regular basis to cause permanent damage.

Who should not be given garlic?
If in doubt always consult your vet for advice, but as it stands the following applies:

  • Medication: If your dog/ cat is taking any medication, check with your vet first before giving garlic.
  • Puppies/ kittens under 8 weeks old should not be fed garlic, as before the first 8 weeks they do not reproduce new blood cells, don’t give garlic to puppies/ kittens under six months. For puppies/ kittens of 6 months to a year, you can feed half the regular dose.
  • Immune disease: As garlic stimulates the immune system, I would not feed it to dogs/ cats with lupus, or any other autoimmune diseases, or pet with anaemic conditions.
  • Gastro intestinal problems: Garlic is high in insoluble fibre and sulphur, so I would not recommend it for dogs/ cats suffering with colitis or IBS.
  • Kidney problems: as garlic contains phosphorous I would not recommend it for pets who suffer with kidney problems like kidney failure
  • Pregnant pets; Always be careful with any medication and or supplement for pregnant pets. Consult your vet when giving garlic to expectant mothers. Garlic also changes the taste of breast milk so avoid feeding it to nursing dogs.
  • Breed Specific Issues: Akitas and Shiba Inus are more sensitive to the hemolytic effects of oxidants such as N-propyl disulphide in garlic, so always consult your vet if you have any of these breeds, or wonder if your pet could develop breed related risks.
  • Garlic affects blood clotting do not use it two weeks before any scheduled surgery.

Drug Interactions
As garlic can interact with several types of medications don’t use it if your dog is on any of these types of prescribed drugs.

  • Immune suppressants
  • Heart medications
  • Chemotherapy drugs
  • Blood thinners
  • Insulin
  • Antacids
  • Medication for high blood pressure.

Side effects/ Garlic toxicity in Dogs and Cats
Symptoms can include:

  • vomiting
  • diarrhoea
  • anemia
  • breathlessness
  • lethargy
  • pale, yellow, or “muddy” coloured gums,
  • rapid breathing
  • elevated heart rate
  • abdominal pain
  • discoloured urine

Now that we have got this out of the way, what is Garlic good for?
What is significant is that all the research supports the positive medicinal powers of garlic.
Garlic is safe when you feed it in amounts suitable for your pet’s size.

A Few ways Garlic Can Help Your Pet

  • Antibiotic: The best known benefit is that garlic acts like a natural antibiotic. Researchers compared the effectiveness of garlic with that of antibiotics and
    found that garlic has a broad antibacterial effect. Bacteria don’t seem to build up a resistance to garlic, whilst they do to modern antibiotics
  • Prevents the formation of blood clots (Hence why not to feed before surgery
  • Decreases cholesterol: Uncooked garlic lowers blood triglycerides and cholesterol, which is useful for some breeds like Schnauzers and Beagles which are susceptible to this problem.
  • Widens blood vessels 
  • Helps prevent the formation of tumours (aids in the prevention of cancer) Sulfide, a compound in garlic aids in preventing tumour formation, garlic increases the immune activity of Killer Cells (cells that seek out and kill invading bacteria and cancer cells).
  • Stimulates the lymphatic system to remove wastes: It also enhances overall liver function and triggers enzyme responses to help break down waste materials before they go into the bloodstream
  • antifungal
  • Anti parasitic: There are many products on the market containing garlic for this purpose. Both powdered and raw garlic are effective, though raw garlic has more health benefits. When using garlic for flea prevention, it is recommended to use a chemical free (Castile) soap or shampoo. Pets don’t sweat like us humans do and the garlic smell comes out on their coat. It takes several weeks for the garlic compounds to build up in the oil of your pet’s coat and a detergent shampoo will removes that oil, so you’ll be back to where you started.

How To Prepare Garlic
To release garlic’s healing properties, it first must go through a chemical process to create allicin.
The best way is to finely chop or crush a garlic clove and wait roughly 10 – 20 minutes to allow the chemical reaction to take place.
Allicin becomes unstable when exposed to air and heat, so don’t wait any longer than 20 minutes before adding it to your pet’s meal.

Dogs and cats can safely consume 1/8 teaspoon of garlic powder per pound of food 3 to 4 times a week.
However as with everything else, fresh is better/ preferred
The recommends amount of fresh garlic according to size is as followed:

  • Up to 3 kg  – 1/6 of a clove
  • 3kg – 5 kg  –  1/3 of a clove
  • 5kg -7 kg  –   1/2 of a clove
  • 7kg – 9kg –   2/3 of a clove
  • 9kg – 20kg – 1 clove
  • 20kg – 31kg – 2 cloves
  • Over 31kg –    2 1/2 cloves
  • Over 50kg –   3 cloves

Even though the recommended dosages go up to 3 cloves a day, personally I would not go over 2 cloves per day.

Sources used:
Oxford Ecademic Garlic consumption and cancer prevention: meta-analyses of colorectal and stomach cancers
Charlton T. Lewis, Charles Short, A Latin Dictionary
ELLEN TATTELMAN, M.D., Albert Einstein College of Medicine of Yeshiva University, Bronx, New York
Pelagia Research Library
Cochrane Library
Self Nutrition Data
Umiversity of California
Wageningen university
Natural Dog Health remedies