Subcutaneous Fluid Administration in Dogs: Syringe Method

Why did my veterinarian recommend at-home subcutaneous fluid treatment?

Supplemental fluids can benefit dogs with a variety of medical conditions. Home fluid therapy is most commonly recommended for dogs with chronic kidney disease (also known as chronic renal failure). If your dog is diagnosed with a condition that will benefit from fluid therapy, your veterinarian can teach you to administer fluids subcutaneously (under the skin). It can be normal to feel hesitant or apprehensive about administering any treatment to your pet.

Giving injections is outside the comfort zone for most outside the medical profession. However, subcutaneous fluid administration is not nearly as difficult as it sounds. The benefits your dog receives will make it well worth your time to learn this simple technique.

There are two ways to give subcutaneous fluids at home: using a fluid bag with a drip set or using a syringe with a butterfly catheter. The syringe method offers more control, while the bag method is ideal for giving larger volumes and often works faster.

How do I administer subcutaneous fluids using the syringe method?

With the “Syringe Method,” you give fluids with a large syringe and a butterfly catheter (a needle attached to a long rubber tube).

1. Find the rubber stopper on the fluid bag and wipe it with alcohol.

2. Insert a needle and syringe through the stopper and into the fluid.

3. Slowly pull back on the syringe’s plunger to suck up the prescribed amount of fluid, then remove the syringe from the bag. Repeat this process with another needle and syringe, if necessary.

4. Remove the needle and replace it with a butterfly catheter (also known as a winged infusion set). Be sure to twist it on tightly to avoid leaks.

5. Place the syringe on a nearby surface while you place the catheter needle under your cat’s skin.

6. Make a “tent” in the skin by lightly pinching it between your thumb and index finger and pulling it up. You can do this anywhere the skin has some stretch.

7. Insert the catheter needle swiftly under the skin in the center of the tented area. The angle of the needle may be 45 degrees or less, depending on how high the “tent” is. 

8. Hold the tube to prevent accidentally pulling it out.

9. Pick up the syringe and slowly depress the syringe’s plunger with your thumb or the palm of your hand to transfer the liquid from the syringe to the subcutaneous area. There will be some pressure as you depress the plunger; if there isn’t, the needle may have come out of the skin.

10. If you need a second syringe of fluid, do not remove the catheter needle. Instead, twist the empty syringe off the end of the butterfly catheter and replace it with the full syringe, and repeat the process.

11. Smoothly withdraw the needle of the butterfly catheter. 

12. Some fluid and occasionally a small amount of blood might “leak” out after removing the needle. Pinch the area or apply light pressure for a few minutes and it should stop.

How should I store and dispose of syringes and needles?

Store the syringes with new, sterile needles to prevent contamination. Keep the equipment in a safe place until the next fluid administration. The fluids should be kept in a relatively cool location out of direct sunlight but do not refrigerate. Be sure to keep this and all medications out of the reach of children and pets.

Dispose of needles in a designated “sharps” container or in a firm, sealable, plastic container. Ask your veterinarian where to safely dispose of the container.

What other tips should I know?

• It is usually not necessary to "sterilize" the skin with alcohol before inserting the needle. Wiping a little alcohol on the skin does not really sterilize it and the odor and feel of alcohol may aggravate your dog.
• Ideally, the fluids should be given at about body temperature. Most dogs tolerate fluid administration quite well, but if the fluids are unusually cold or hot, they may be uncomfortable. Warm the fluids in a water bath to increase comfort. Ensure the fluids aren’t too hot by placing your wrist on the bag to check the temperature. Do not refrigerate them.
• As the fluids are running, a lump will form under the skin. Do not be alarmed; this pocket of fluid will be absorbed over the next few hours. If absorption is slow, gravity may cause the fluids to migrate downward along the side of the body. Fluids may even move under the skin of the front or rear legs in rare instances. Do not be alarmed. If this happens, the fluids will still be absorbed and your dog will not be in any pain or discomfort.
• You will not cause any problems if you inject a few bubbles of air under the skin. If quite a bit of air gets under the skin, you may feel a crackling sensation when you push on the skin, and your dog may experience mild discomfort for a couple of hours, but no real harm or damage will occur. The body will eventually absorb the air without difficulty.
• Use a creamy treat or baby food (no garlic/onion) to keep the dog’s focus away from what you are doing. Or, if your dog prefers cuddles, you or an assistant can rub them around their head and neck while you give the injection. 
• Practice the procedure without a needle, but with the same rewards, to help your dog relax for the real thing.
• If your dog is sensitive to needles, ask your veterinarian if you can use a numbing cream.