DIY Essential Oil Dog Flea Treatment Flea Collar What you’ll need: A standard dog collar 2 tbsp almond oil 2 drops of flea repelling essential oils such as cinnamon, rosemary, clove, peppermint, and cedar wood (2 drops in total. If you are using a combination of oils, such as rosemary and cinnamon for example, 1 drop of rosemary and 1 drop of cinnamon) Instructions: Mix the oils together and apply them to the collar. Allow to dry before placing on your pet.