Subcutaneous Fluid Administration in Cats

A variety of conditions are treated in cats with subcutaneous fluid administration. This refers to the procedure of administering fluid, usually lactated ringer's solution, through a needle inserted under the skin. This treatment is used to treat or prevent dehydration in your cat and is commonly prescribed for cats with kidney disease, but also for cats experiencing dehydration in a variety of situations in which intravenous therapy is not a good option (or not affordable) for administering fluids.

This procedure may be performed by your veterinarian in response to an acute conditions resulting in dehydration or when chronic kidney disease is present. Your veterinarian may instruct the pet owner on how to administer fluids at home to care for an animal with a chronic condition.

Your veterinarian will determine the appropriate amount of sub-q fluid to be administered based on your cat’s weight, hydration levels and condition. Ringer's solution is used, it may be supplemented with vitamins, minerals, electrolytes or other substances your veterinarian deems necessary. Solution should be stored in a cool place out of light and should be administered at room temperature if possible. Cats with CRF will require this treatment regularly, anywhere from once a week to daily.

When fluid is administered a lump of fluid will accumulate under the skin, this fluid will be absorbed by your cat's body over the next few hours. There are a variety of methods used to administer fluids below your cat's skin.

Syringe Method

The syringe method is used when small amounts of fluid are required quickly or when control of exact amount and speed of administration is required, for example where a heart condition exists. It may require assistance from a helper to restrain the cat during the process. Fluids are drawn from the bag of fluid by a large syringe, a butterfly needle is inserted under the skin, and the syringe is attached to the needle and fluids administered via the syringe to the cat. If more than one syringe is required, the syringe will be disconnected from the needle and another syringe with fluid attached to the needle to prevent the need for multiple punctures. There is some discomfort involved.

Giving Set Method

The giving set method requires a bag of solution, attached to a tube, which has a volume control/lock apparatus attached to the tubing and a needle at the other end of the tube. The tube should be firmly inserted in the bag with the lock closed, the lock has a roller which can be adjusted to shut off or open the tube and control the flow of fluid. The lock will be opened, the fluid will then be allowed to run through to remove any air bubbles and the needle attached. It is important when handling this apparatus that the ends of the tube not be allowed to touch anything as they are sterile and need to remain so. The needle will be inserted in the loose skin on the shoulder blades or hipbones either to the right or left of the midline. The needle should be inserted with the sharp end pointing toward your cat's head and horizontal to the skin surface. The needle will be inserted gently but firmly into your cats roll of skin and then the lock on the tubing released to allow the flow of fluid. The procedure will take about 10 to 15 minutes, so it is important for your cat to be in a comfortable position and helpers available to restrain the cat if required. The bag should be elevated about 1 meter above your cat’s head. The choice to give the fluid in two locations so that there is not a large fluid build up in one location may be made. Usually an average cat will receive 100-150 ml of fluids at one treatment time. When fluids have been administered the lock will be closed and the needle removed. The needle should be capped so as not to present a needlestick hazard. If the set is going to be used again a new needle should be placed on the set immediately after use. 

Catheters and Skin Buttons

For chronic conditions requiring ongoing treatments, catheters or skin buttons may be considered to eliminate the need for repeated needle insertions. A catheter can be inserted subcutaneously and fixed in place while your cat is under anesthetic which will allow for the sub-q fluids to be hooked up directly to the catheter and administered without inserting a needle. This is a more invasive procedure and there is a risk of infection, blockage or irritation to your cat’s skin present with this method.

Another method for administering sub-q fluids is the use of a “skin button” which uses a hypodermoclysis, a small circle with two parts, one on the surface of the skin and one subdermally. It can be inserted with local anesthesia and allows the skin to grow around the “button” decreasing the risk of infection. The “button” acts as a port for fluid to be administered, again eliminating the need to insert a needle. It can however become blocked or cause irritation to your cat.

Subcutaneous fluid administration is not as direct a method for administering fluids as intravenous fluid therapy. Sub-Q fluid administration must absorb through the tissues and is not delivered immediately via the circulatory system, however it is useful in a situation in which intravenous administration is not possible. Also, for cats living with CRF, sub-q administration allows for ongoing treatment by pet owners and can potentially allow cats with this condition to live longer than they would without it.

Immediately following sub-q administration of fluids your cat will have a lump where the fluid was inserted. This is normal and the fluid will absorb into the tissues. The fluid may move down into the abdomen or legs. Some cats are somewhat lethargic after treatment. Occasionally, fluid, sometimes with a small amount of blood in it, will leak out of the injection site, this is not cause for alarm and will stop when fluid pressure decreases. Some cats do not tolerate this therapy well and find it stressful, if they have a chronic condition requiring treatment, an alternative solution may be needed. Cats with chronic conditions, or those experiencing an acute condition that has affected electrolyte imbalance or organ functioning may require a special diet after treatment to ensure return to normal functioning.

The cost of subcutaneous fluid administration in an emergency or acute situation will vary depending on the condition being treated and other veterinary care requirements. 

The cost of subcutaneous fluid administration for chronic condition such as kidney disease from a veterinarian is about $25 per treatment, for a cat requiring multiple treatments per month this can equal approximately $300 per month. If prescribed by a veterinarian for administration at home, the cost is approximately $30 per month. 

A catheter or skin button costs approximately $100 plus the cost for insertion and required anaesthetic expenses.

For cats with chronic kidney conditions, sub-q fluid administration is a critical tool in extending their lives. However, cats with heart conditions may not be good candidates for this treatment. 

There is a risk if excessive fluids buildup in the pleural or abdominal cavities. Some cats do not tolerate this treatment well and it is extremely stressful to them, taking away from their quality of life if required in a chronic situation. Alternatives may need to be examined in these cases.

Preventing the requirement for sub-q fluid administration requires close monitoring of your cat to ensure they do not become dehydrated when experiencing illness or injury. A cat that is vomiting or has diarrhea should be examined by a veterinarian to ensure that they receive adequate treatment to address these symptoms before dehydration occurs. Feeding your cat an appropriate diet will also help to address any deficiencies in organs that may result in disease causing hydration problems and the need for subcutaneous fluid administration.