IV Fluids- What are they?

Intravenous fluids can be described as placing an IV catheter into the vein to put the fluid directly into the bloodstream. It is the fastest route of treatment with either medications or fluid replacement into the body because of the immediate access to the circulatory system. It can be useful for many things such as surgical procedures when the animal is in shock, when the animal is dehydrated, if they have an illness, and in certain cases, if the animal has gotten into certain types of poison.

Each case is handled in an individual case-by-case treatment plan. It depends on the severity of the condition, the case, and the individual animal itself; the patient’s clinical condition and type of shock dictates which fluid type we would use. The location in which the fluid is administered, fluid composition, rate, and volume are dictated by the needs of the patient. Fluid therapy can be administered to an animal intravenously (through the vein), subcutaneous (under the skin), intraosseous (through the bone), or intraperitoneal (through the abdomen). In general, the procedure for administrating fluid therapy is the same with any of these methods. The only difference is the placement of a catheter location and rate of administration.

The intravenous route is the fastest way to deliver medications and fluid replacement throughout the body because they are introduced directly into the circulation. Intravenous therapy may be used for fluid volume replacement, to correct electrolyte imbalances, blood transfusions, and to maintain normal hydration.

When to use them?

  1. Surgery – Fluid therapy during surgery has many variables. It can depend on the patient’s age, breed, sex, their actual condition, the length and the specific type of procedure being performed. These things can tell you what volume and type of fluids to use. It can help stabilize blood pressure. Also, if there is any blood loss, the fluids will help the body recover from this. It helps with circulation to all the organs and helps the blood flow deliver oxygen to all the cells in the body.
  2. Shock – IV fluids can be useful for the treatment of circulatory shock and helps to restore circulating blood volume. Rapid progression of shock can be fatal due to major organ failure (ex: heart, brain). Fluid therapy can help improve cardiovascular function, encourage the heart muscle contractions, and blood flow throughout the extremities, which is needed in shock patients. It also helps to regulate cell function, assist those animals with circulatory shock, penetrating wounds, and brain trauma.
  3. Dehydration – We all know how important water is to living things—without it, we couldn’t survive. Water in our cells helps with many things including regulate body temperature, aids in digestion, transports oxygen and nutrients, lubricates joints, energizes muscles, and basically keeps our organs functioning (especially the liver and kidneys). If these organs are unable to function properly, they might be unable to perform critical functions, which might include detoxifying drugs and removing waste products from the body. An animal becomes dehydrated the same way a human does- when the output of fluid becomes higher than the input (ex. If the animal has been vomiting and/or has diarrhea and is not eating or drinking, or when they are very active or sweating and then not drinking enough water).
  4. Illness/disease – Any illness causing vomiting and/or diarrhea can be supported with IV fluids. If the output of fluids is higher than the input of fluids, dehydration happens quickly, as mentioned before. IV fluids can help to rehydrate and support the body to overcome the illness that is causing the vomiting or diarrhea, whether is it bacterial or viral. Antibiotics may be given directly into the body through the IV line to help fight off bacterial infections. Viral infections need to run their course, and we must give as much supportive care as we can, with IV fluids being the most effective form of support. Other diseases such as kidney or liver failure or pancreatitis can be supported with IV fluids because the fluids help the affected organs to flush out any toxins or waste out of the body that a normally functioning organ should be able to do on their own.
  5. Poisons – The fluids dilute the concentration of toxic substances in their body. Intravenous fluids support circulation to the organs, especially the kidneys and liver, which can be very sensitive to toxic effects. They
  6. Hyperthermia (aka Heat exhaustion) – We administer room temperature IV fluids to a patient who has heat stroke because we don’t want to shock the system with too cold fluids entering the body suddenly. By administering a bolus (large volume) as an initial treatment, we are able to support the cardiovascular system with cooling the body by increasing blood flow to the peripheral limbs and expanding the intravascular space to allow for more circulation to decrease temperature. In severe cases, further hospitalization is required. It is to continue supporting the body with fluid therapy and any ongoing losses of fluids from vomiting and or diarrhea (both of which are symptoms of severe heat exhaustion).

As you can see, fluid therapy is a very helpful tool in the veterinary medical field. It has many uses, types, rates, and routes of administration. Each case is individual, and our highly trained staff are able to use this course of treatment/support to provide the best care for your pet.

If you have any questions, give us a call at 780.539.0636.

Written by: Miranda Kitzul, RVT



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Last updated: April 30, 2021

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