Fortunately, it sounds like the LD50 is pretty high.
Scientific studies have found it takes approximately 15 to 30 grams of garlic per kilogram of body weight to produce harmful changes in a dog’s blood. To put that into perspective, the average clove of supermarket garlic weighs between 3 and 7 grams, so your dog would have to eat a lot to get really sick.
Fortunately, it sounds like the LD50 is pretty high.
Still best to avoid it if possible, obviously.