Fluid therapy refers to the administration of fluids to a patient as a treatment of dehydration, electrolyte imbalance, sugar imbalance, or as a preventative measure. This fluid can be a given either orally or by injection. The most common methods are intravenously (IV or into a vein) or subcutaneously (under the skin). Fluids can also be given directly into the abdominal cavity or into the marrow of the bone, but this is extremely rare. Fluid therapy given intravenously has long been a standard procedure in medicine, both human and veterinary. An IV is also known as a “life line” providing the means for administering medications on an emergency basis, many life saving. There are many other reasons for an IV as well. Approximately 60 % of the body is water. Over 40% of the fluids in the body are within the individual cells and the rest are within the blood vessels, lymphatics, and between the cells in the tissue. To maintain normal body functions, this fluid level must be maintained at the proper levels, as many things can affect it. Any stress such as disease, trauma, blood loss, vomiting, diarrhea, etc., can and does affect the fluid balance within the body. It is the veterinarians job to safeguard the pet in their charge, and fluid balance is an integral part of that responsibility. During minor anesthetic procedures such as teeth cleaning, there is stress involved and thus the need for a “life line”. Having direct access to the vascular system by means of an IV allows the veterinarian the ability to maintain normal hydration as well as a means to administer intravenous medication, electrolytes, and nourishment, if necessary quickly. Maintaining the proper fluid level not only treats the dehydration, in a vomiting dog for example, but actually prevents certain problems from surfacing at a later date, even in normal pets. Fluids given subcutaneously works much slower, but often it is easier when speed is not necessary. It is without question that IV fluid therapy used as a “life line” or given subcutaneously to maintain hydration, represents a standard of care that owners want for their beloved pets and what veterinarians want for their patients.