Fig. 5. A, The 20-gauge, 1.25-inch catheter is inserted into the SPL tubing near the withers to create the injection port. B, The injection port is closed with a male catheter cap. The tubing end and port are braced with a few pieces of gauze and a tongue depressor and taped and sutured to the anchoring mane braid.
port exposed. Tape wings are then used to secure the “braced” injection port to the anchoring braid. In some cases, tape wings are then sutured to the braid twists to further ensure that the port is well attached to the mane braid. Care taken with se- curing the port should ensure that the braid will not unravel with normal stable activity, even if the de- vice remains in place for several weeks. A heavy plastic bag can be taped over the injection assembly to keep it clean. Neonates and very young foals must undergo short-term general anesthesia or heavy sedation to induce lateral recumbency for safe insertion of an SPL, but all other steps in the process remain the same. Very young foals will not have enough mane to make braids, but adhesive tape can be wrapped around short mane hairs to create a series of tufts that will serve the same purpose. The injection port assembly may need to be sewn to the skin (Fig. 6). Some clinicians slip a section of wide stockinette over the head and neck of the foal to protect the tubing from damage. Holes can be cut in the stockinette to provide openings for the eyes. A series of tape butterfly guides must be sutured
close to the crest of the neck to secure an SPL in an adult horse that has had the mane shaved off (roached).
Use of an SPL to Deliver Ocular Medication
Treatment involves injection of medication into the tubing cap. The tongue depressor support taped to the mane braid makes a secure handle to access the injection cap. Medication that has been drawn up
168 2013 Vol. 59 AAEP PROCEEDINGS
Fig. 6. Tufts of mane can be used as a channel for SPL tubing in young foals. Two injection ports were secured to the skin of this foal’s neck.
into a tuberculin syringe is injected through a 25- gauge, five-eighths–inch needle (Fig. 7). Most med- ication is dosed at a volume of 0.2 mL. Some very costly medications are dosed at a volume of 0.1 mL.d The medication is then “pushed” toward the eye by a
