• Register at COSTCO Online. To order from the Pharmacy, you must register yourself at COSTCO Online.  You do not have to be a COSTCO member to join.  Members and non-members are charged the same prices for prescription drugs.
• Register Your Cat at the Online Pharmacy. You must register your cat as a "patient" in the Online Pharmacy section.  Click on patient information and enter the cat's first name preceded by Feline, e.g., Feline Scooter.  (The Feline entry in the first name section will allow COSTCO to track orders for the CRF program.)  Enter your last name as the "patient's" last name, and the shipping address.
• Submit a Prescription for the Items You Want.  All items above require a prescription.  Have your vet call (1-(800) 607-6861) or FAX (1-800-633-0334) the prescription to the COSTCO Online Pharmacy.  Prescriptions are good for a year, so make sure your vet indicates that refills are permissible. 
• Submit Your Order.  With your cat registered as a "patient" and your prescription in place, you can order against that prescription using COSTCO Online's web site or 800 number (1-(800) 607-6861).  The items above are not yet listed in the COSTCO Online inventory.  If ordering on the web site, type the item names and quantities into the blank spaces on the prescription drug order form.
• Problems and Complaints.  If you have a problem with an order and/or a complaint, email the Costco Online Pharmacy or contact them by phone - 1-800-607-6861.  You must, however, submit your order via their web page.

Assuming you have already registered yourself and your cat in the COSTCO system, here's how you order. 

1. Go to Costco.com and navigate to the Pharmacy area.
2. Select fill precriptions.
3. Select order new prescriptions.
4. At this point the system may ask you to log in with your e-mail address and Costco password.
5. Near the bottom of the next page there are five empty boxes for filling in what you need.  For example, you would enter Lactated Ringers and the number of bags in one box, IV Administration sets and the number of sets in another, and Terumo needles, the number of boxes, and the gauge you would like in a third.  You also need to fill in the rest of the information regarding the vet, etc., and select whether you will mail the prescription or have your vet call or fax the prescription to COSTCO.  If you select the call or FAX, there are numbers that you will be given on the page that pops up after you enter the items you want.  Depending in part on how fast your vet is, there will be about a 2-3 day delay before your prescriptions are ready.
6. You should receive an e-mail confirmation or two from COSTCO.  Later, you can go back to the Pharmacy web site and select Order Status to see if your prescription is ready to be filled.  If it is, it's pretty standard from there (fill your cart and check out).