For your dog you should fill the syringe to the 0.6 mark on the 1.0 mL syringe. For your cat, you should fill the syringe to halfway between the 0.1 and the 0.2 mark - there are probably smaller dashes between 0.1 and 0.2 to help you with this.
If you aren't sure, you should ask your veterinarian to show you on the syringe how full to fill it.