In veterinary medicine, fluid therapy is given in four ways,
- Oral – by mouth
- Intravenous – through an intravenous catheter
- Intramedullary – within the medullary canal of bones
- Subcutaneous – under the skin
Subcutaneous administration means fluids are injected under the skin using a needle. The fluids accumulate into a large pouch between the shoulder blades. This gives the patient a ‘hunchback’ look. Overtime, the fluids are absorbed into the animal’s bloodstream. Because it takes time for the absorption to take effect, the subcutaneous route is not appropriate for animals who need fluids immediately. The intravenous or intramedullary route is used for these cases.
To perform subcutaneous fluid therapy, I recommend cleaning the skin where the needle will be placed with an antiseptic solution to prevent infection. Next, the skin is pulled up off the animal’s body making a ‘tent’. A sterile needle is inserted into the base of the tent and the fluids are injected. A new needle is used for every treatment. Needles should not be reused under any circumstances as they become dull and contaminated.
Only sterile, non antigenic fluid can be injected under the skin. Examples of appropriate fluids include lactated ringers solution, Normasol, Plasmalyte or saline. Fluids that contain any form of sugar (glucose or dextrose), high osmolality and/or unsterilized fluids should never be used for subcutaneous administration. Sugar causes a horrific reaction that often causes abscess formation and sloughing of the skin. The sugar placed in the warm subcutaneous space creates a perfect incubator for bacteria. I saw a dog go into septic shock after it was given Pedialyte subcutaneously. These animals are in extreme pain. I have seen dogs and cats lose all of the skin on their backs from sugar. Even with extensive skin grafts and hospital care, some of these animals died. Here are a few examples of fluids that should never be used for subcutaneous fluids. Pedialyte, D5W, Gatorade and mannitol.
Please talk to your veterinarian before giving any medications or therapy to your pet!