Garlic is not dangerous to dogs unless they are fed too much of it. As long as they don't eat more than .5% of their body weight in garlic in one day they will be fine. Garlic actually helps repel fleas but again should always be given in small doses. So these biscuits should be fine as long as they are not given to the dog too much in 1 day.
What an easy recipe! Didn't have meat drippings, so used about 1 TBS. dry beef gravy mix, and an extra 2 TBS. water. The kids had a blast making dog bones and other shaped treats with their playdough toys. The neighbor's dog gave this a tail-waggin paws up and snarfed them down. (If you are concerned with the garlic, check with your vet; online views seem to think garlic is fine for dogs.) Thank you for sharing this fun recipe.
Garlic in any form (clove, powder, crushed, whole etc) causes pancreatitis in dogs.