While the epidural vertebral vein of phocids is readily accessible, repeated needle insertions to provide IV medications or obtain blood samples from debilitated animals can be locally damaging. These concerns can be mitigated by using long-term catheters, but the depth of this vein and the surrounding anatomy make it challenging to set and maintain standard, peripheral over-the-needle catheters. A technique developed for obtaining serial research blood samples from seals can be used to safely set a 15-cm catheter in rehabilitating phocids. All supplies can be assembled separately or are available in kits (long-term catheter, guidewire style; Mila International, Inc., Florence, KY). Unless the animal is moribund, sedation in combination with physical restraint may be required to keep the animal sufficiently still during the procedure. The area over the lumbar vertebrae is shaved, prepped, and injected with a local anesthetic. A 16-guage over-the-needle catheter of appropriate length for the patient is used to initially gain access to the vein. Following removal of the needle, a ‘J’ tip guidewire is slowly fed into the vein and the initial catheter is replaced with a 16 g x 15 cm indwelling catheter. After removal of the wire, an extension set, or cap can be attached to the catheter hub which should be sutured in place. The site can be further protected with a neoprene patch glued to surrounding fur. This set up has been maintained successfully for several days in rehabilitating phocids at the Alaska SeaLife Center.