What term describes the administration of drugs directly into the veins of an animal?

The administration of drugs directly into the veins of an animal is best described as intravenous injection. This method allows for immediate access to the circulatory system, ensuring rapid distribution of the medication throughout the body. It is particularly useful in emergencies when swift action is required, such as delivering fluids to a dehydrated animal or administering anesthetics.

Intravenous injection is distinct from other forms of administration, such as subcutaneous injection, which delivers drugs into the tissue beneath the skin, intramuscular injection, that involves injecting into the muscle layer, and topical administration, which applies medication directly onto the skin or mucous membranes. Each of these methods has its own specific applications, advantages, and limitations based on factors like the speed of absorption, ease of administration, and the type of medication being used. Using intravenous injection provides the benefit of precise dosing and immediate therapeutic effects, making it a critical technique in veterinary medicine.