Placement of a butterfly catheter. Small Animal Diagnostic and Treatment Techniques

Butterfly catheters have a steel needle (a) attached to flexible plastic wings (b) and a short piece of extension tubing (c). A 3 way stopcock (d) is attached to the catheter in this slide but is not used when the butterfly catheter is placed IV. The 3 way stopcock is used when the butterfly catheter is used for thoracocentesis (see thoracocentesis from selection menu for details).

Butterfly catheters are used for short term administration of drugs (drugs administered over a few minutes). For example, the anticancer drug vincristine or thiacetarsimide which is used to kill adult heartworms. Both of these drugs are very caustic to tissues. To assure that the injection is being administered IV rather than SC, sterile fluid is flushed through the catheter before and after drug administration.

Placement of a butterfly catheter allows you to easily change between syringes containing drug or saline. It usually takes less time to place a butterfly catheter compared to other cephalic catheter types. Butterfly catheters are not taped in place for longer term use as the needle will lacerate the vein as the animal moves about.

The catheter can be filled with saline before placement or air can be left in the line, depending upon blood to displace the air. The wings are folded up and held between thumb and index finger. The skin and vein are punctured with one thrust of the needle. The needle is beveled and should be placed with the opening of the bevel facing up. Notice the thumb of the hand holding the leg is placed adjacent to the vein to stabilize it.

The needle is inserted into the vein to the level of the plastic wings. Notice that the catheter has been placed at the junction of the cephalic vein with the accessary cephalic vein.

The thumb of the hand holding the leg is used to hold the catheter in place during drug administration. The catheter and leg will move as a unit when held with the same hand, preventing the needle from accidently withdrawing from the vein during drug administration.