Which abbreviation denotes an injection directly into the bloodstream?

The abbreviation that denotes an injection directly into the bloodstream is "IV," which stands for intravenous. This method involves administering medication or fluids directly into a vein, allowing for rapid absorption and immediate action in the body. IV injections are commonly used in veterinary medicine for various purposes, including hydration, medication delivery, and emergency treatments, as they provide precise control over the dosage and effects of the substances being administered.

In contrast, the other abbreviations represent different routes of administration: "IM" refers to intramuscular injections, which are delivered into a muscle; "SQ" indicates subcutaneous injections, administered into the tissue layer between the skin and muscle; and "PO" stands for oral administration, where medication is given by mouth. Understanding these abbreviations is crucial for effectively communicating and documenting medication administration in veterinary practice.