Dogs differ anatomically and physiologically in several key areas in comparison to people. Knowledge of these differences will assist HCPs when managing MWDs.
Most MWDs are German shepherd dogs, Belgian Malinois, and Labrador retrievers, with a weight of 50-80# (23-36 kg). Dose drugs based on actual body weight whenever possible.
Canine blood can be tested using analyzers designed for people, with generally reliable results. Interpretation of results may be unreliable or misleading for albumin and total calcium, however, due to species-specific methodology differences. For all other parameters, if the results appear reasonable, trust them for decision-making.
Venous blood sampling and IV catheterization sites:
Use the cephalic or lateral saphenous veins for routine blood sampling, drug administration, and routine intravenous fluid therapy. Use the external jugular vein for long-term fluid therapy, large volume fluid delivery, and repeated blood sampling.
Figure 1. Cephalic Vein Location on Superior Aspect of Forearm.
Figure 1 shows cephalic vein location on the cranial (superior) aspect of the forearm.
The vein is best punctured toward the elbow, as the accessory cephalic vein and cephalic vein join in a Y-shaped configuration more distally (toward the carpus).
Figure 2. Occluding the Vein.
Figure 2 shows proper technique for an assistant to occlude the vein, while extending the elbow joint. The assistant’s thumb occludes the vein while rolling the vein outward at the elbow.
Figure 3. IV Catheter in Cephalic Vein of Forelimb.
Figure 3 shows properly placed and secured IV catheter in the cephalic vein of the forelimb of a MWD.
Figure 4. Lateral Saphenous Vein Location.
Figure 4 shows location of the lateral saphenous vein on the hind limb of a MWD, located on the lateral aspect of the distal tibial area, coursing caudodorsally from the hock (ankle) and over the gastrocnemius tendon.
Figures 5 – 16: External Jugular Vein Location and Central Venous Catheterization.
Figure 5 shows the right external jugular vein (dotted lines) located in the right jugular furrow. The vein is best punctured distal to the junction of the more-proximal tributaries (the optimal insertion site is noted by the red oval). Hair should be clipped and a sterile preparation should be performed.
Figure 6 shows a small skin nick (noted in the red oval) created over the intended catheter insertion site to facilitate penetration of the thick skin of the dog. This nick can be made with the tip of a #11 scalpel blade or the bevel of an 18-gauge needle.
Figure 7 shows insertion of a large bore catheter-over-needle through the skin nick, penetrating the skin and entering the external jugular vein. Note the use of the thumb of the opposite hand to occlude the vein. In this figure, and in Figures 8-12, sterile draping is removed to provide better visualization; perform catheterization using sterile technique.
Figure 8 shows full insertion of the over-the-needle catheter into the external jugular vein, after removal of the needle.
Figure 9 shows insertion of a Seldinger guide wire adapter into the hub of the catheter that has been placed into the external jugular vein.
Figure 10 shows advancement of the Seldinger guide wire through the catheter and into the external jugular vein. Once the guidewire is advanced about two-thirds of its length into the vein, remove the catheter, leaving only the guidewire in place.
Figure 11 shows initial advancement of the multi-lumen central venous catheter over the guidewire. Use of a dilator (not shown) is often necessary before this step to enlarge the puncture site in the skin.
Figure 12 shows advancement of the catheter into the external jugular vein. Note extension of the guidewire from the proximal end of the catheter (red oval).
Figure 13 shows full insertion of the catheter into the external jugular vein, complete removal of the guidewire, and attachment of an injection port on the catheter hub.
Figure 14 shows the optimal method to secure central venous catheters to the dog’s skin using separate sutures at the wings of the catheter hub and circumferentially around the catheter base.
Figure 15 shows the optimal method to initially secure the central venous catheter using roll gauze or cast padding. Note that the catheter tubing (dotted line) is gently curved caudally and secured between snug layers of gauze/padding.
Figure 16 shows the optimal method to completely secure the central venous catheter using non-adherent bandage material placed over the underlying roll qauze/padding. Note: At least 2 fingers can be inserted beneath the bandage, ensuring the bandaging is not too tight.