Your dog is going to love these. Probably your cat, too (omit garlic if making this for your cat).
It will keep all day while you carry it around in your pocket.
When the liver is dried it can be stored in the fridge for about a week or in the freezer for about 3 months (in a sealed container).
Regarding garlic and dogs:
Many dogs enjoy the taste of garlic and it's a natural flea repellent. A small bit of cooked garlic should not be toxic. However, according to the American Animal Hospital Association, raw and spoiled garlic is toxic and potentially fatal to dogs. Consult with your veterinarian before using and use in small quantities. This recipe instructs the cook to discard the garlic after it has been cooked.