Needles and Winged Infusion Sets are used to administer subcutaneous fluids to renal patients. ThrivingPets recommends and exclusively stocks Terumo needles because feedback from our clients has been overwhelmingly positive for Terumo products. Selecting the best size needle can be a bit tricky as one needs to trade off the increased comfort and reduced scar tissue from smaller needles with the increase time to administer fluids from smaller needles. Our cat and small dog clients prefer 20 gauge needles. Our medium and large dog clients typically choose 18 gauge needles. Please note with needles, the higher the number, the smaller the needle.