# The Effect of the Type and Concentration of Garlic (Allium sativum) on Heinz Body Concentrations in Canine Erythrocytes—An In Vitro Study

## TL;DR

This study shows that processed garlic (dried or granulated) is more harmful to dog red blood cells than fresh garlic, increasing the risk of anemia.

## Contribution

The study reveals that processing garlic increases its harmful effects on canine erythrocytes, as measured by Heinz body formation and hemolysis.

## Key findings

- All forms of garlic caused hemolysis in dog red blood cells, with granulated garlic at 0.2 g/mL being the most damaging.
- Dried and granulated garlic led to more Heinz bodies and eccentrocytes compared to fresh garlic.
- Processing methods like drying and granulation may enhance the release of harmful compounds in garlic.

## Abstract

Garlic is a popular food ingredient and natural remedy for people, but its use in dogs may not be safe. Many owners believe that garlic can protect their pets against parasites or improve their health, yet garlic also contains substances that may damage red blood cells. When red blood cells are harmed, they lose their ability to carry oxygen, which can lead to anemia. In this study, we wanted to find out whether fresh, dried, and granulated garlic can cause different levels of damage to dog red blood cells. We mixed garlic extracts with blood samples taken from healthy dogs during routine veterinary procedures. We then measured the amount of hemoglobin, the protein that carries oxygen, and looked at the cells under a microscope to check for signs of damage. We found that all forms of garlic caused some harm to the red blood cells, but dried and granulated garlic were more damaging than fresh garlic. These results suggest that processing garlic may make it more harmful for dogs. Our findings highlight the need for caution when using garlic in pet diets and show that more research is needed to identify what level, if any, of garlic is safe in dog food and supplements.

Garlic (Allium sativum) is widely used in human diets and medicine, but its safety for dogs remains uncertain. Heinz bodies in red blood cells are indicators of oxidative damage, which may lead to hemolytic anemia. This study evaluated the effects of different forms and concentrations of garlic on canine erythrocytes in vitro. The experiment consisted of two phases: Phase 1 compared fresh, dried, and granulated garlic, while Phase 2 assessed two concentrations of granulated garlic (0.1 and 0.2 g/mL). Blood from healthy dogs was incubated with ethanol extracts of garlic. Hemolysis was measured spectrophotometrically by hemoglobin release, and blood smears were examined for Heinz bodies and eccentrocytes. All garlic preparations caused hemolysis, most strongly granulated garlic at 0.2 g/mL (p < 0.01). Blood smears confirmed red blood cell damage, with more Heinz bodies and eccentrocytes in dried and granulated garlic samples. In conclusion, the form and concentration of garlic strongly influence its hemolytic activity. Processing methods such as drying and granulation may enhance the release of reactive compounds, increasing the risk of oxidative damage to canine red blood cells.