The belief that garlic is toxic to dogs is widespread among pet owners and even some veterinarians. However, recent studies suggest that this concern may be overstated, particularly when considering the form and dosage of garlic administered. And many companion animal nutritionists will agree.
But... why do people still think garlic is unsafe for dogs? Garlic has been used in the equine industry for years with horse owners swearing by its benefits.
This common bias comes from the fact that garlic belongs to the Allium family. Same family of vegetables as onion, leek, chive, and shallot. All of these contain a variety of sulfur-based compounds, but only onion, leek, chive, and shallot possess a lot of the worrying compound thiosulfate. This compound is toxic for canines (but not for humans).
When ingested in a large amount in canines, this thiosulfate causes oxidative damage in red blood cells, resulting in “Heinz Bodies” that the body rejects and expels from the bloodstream. Over time this can result in Hemolytic Anemia and may even cause death.
Examining the Evidence
A pivotal study conducted in 2000 at Hokkaido University investigated the effects of garlic on canine health. 8 Dogs were given 1.25 ml of garlic extract per kilogram of body weight for seven days. As an example, if they used 20kg dogs, each dog woud have been given 100g of garlic (20 cloves of garlic)! The results showed a decrease in red blood cell count and the presence of Heinz bodies, indicators of oxidative damage. However, none of the dogs developed hemolytic anemia or showed outward signs of toxicity. Due to so many flaws in this study, it is easily seen why it cannot be trusted in giving advice on canine nutrition!
In contrast, a 2018 study examined the safety of aged garlic extract (AGE) in dogs. Beagles were administered AGE at doses of 45 or 90 mg per kilogram of body weight daily for 12 weeks. The study found no adverse effects on clinical signs, blood parameters, or the presence of Heinz bodies and eccentrocytes. Additionally, AGE appeared to upregulate antioxidant enzyme genes, suggesting potential health benefits.
Safe Usage Guidelines
The discrepancy between these studies highlights the importance of garlic's form and dosage. Fresh garlic contains compounds that can be harmful in large amounts, while aged garlic extract lacks these harmful compounds and may offer health benefits. A general guideline suggests that a safe amount of fresh garlic for dogs is around 56 mg per kilogram of body weight, though individual sensitivities can vary.
Nutritionists and some vets follow the below feeding guidelines based from the book The Complete Herbal Handbook for the Dog and Cat by Juliette de Bairacli Levy
5 to 9 kgs – ½ clove
10 to 17 kgs – 1 clove
18 to 32 kgs – 2 cloves
35 to 40 kgs – 2½ cloves
45 kgs and over – 3 cloves
Preparation & Benefits
Use fresh and orgsnic garlic, not tinned or garlic in a jar with oils and additives.
Make sure to peel the garlic before mincing or crushing
Introduce slowly after consulting your vet or nutritionist
Benefits of garlic include:
Liver support
Eases Inflammation
Supports digestion
High in antioxidents
Cardiovascular Benefits
Boosts the immune system
Special Considerations
Some medications don't mix well with garlic so ask your vet if your pet is on:
Heart medication
Immunosuppressants
Chemotherapy
Blood thinners
Blood Pressure medication
Insulin
Conclusion
While very high doses of fresh garlic can cause oxidative damage to red blood cells in dogs, leading to conditions like hemolytic anemia, moderate amounts, are safe and may even confer health benefits. As with any supplement, it's crucial to consult with a veterinarian or nutritionist before introducing garlic into your dog's diet to ensure it aligns with their specific health needs. Will you be adding garlic to your dog's diet? Leave us a comment and let us know!
Comments