Which of the following routes of administration requires that the animal be sedated or anesthetized?

• A. Intravenous
• B. Intramuscular
• C. Intraperitoneal
• D. Subarachnoid

Answer: (D)

Administering into the subarachnoid space is highly invasive because it targets the central nervous system by delivering a substance into the cerebrospinal fluid surrounding the brain and spinal cord. This procedure is intensely painful and carries a high risk of tissue injury if the animal moves or flinches during needle insertion. To protect welfare and ensure a precise, safe location, the animal is sedated or anesthetized so it remains still and experiences no pain during the procedure.

Other routes involve less direct access to CNS structures and are typically performed under restraint rather than general anesthesia. Intravenous, intramuscular, and intraperitoneal injections are routine injections that can be done with the animal awake or under light restraint, depending on the protocol and species, so they do not inherently require sedation by the route itself.