Infraorbital nerve block in the cat: the ocular risk
9-year-old domestic shorthair cat, 4 kg, scheduled for extraction of the upper fourth premolar due to tooth resorption. A locoregional block with bupivacaine is planned to reduce isoflurane requirements and improve postoperative analgesia.
Which statement about the infraorbital block in the cat is correct?
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A. The canal is very short: do not advance the needle inside it, as the globe may be punctured
Correct. In cats, as in brachycephalic dogs, the infraorbital canal is only a few millimetres long and opens next to the orbit. Advancing the needle into the canal can injure the globe; the local anaesthetic is deposited at the foramen entrance or a maxillary block is chosen with care.
B. It is done as in a mesocephalic dog, advancing the needle to the end of the canal
This is the error that causes the complication: the mesocephalic dog technique cannot be extrapolated to the cat, whose canal is much shorter.
C. The canine per-kilo bupivacaine dose can be used, because cats tolerate it better
The opposite is true: cats are more sensitive to systemic local anaesthetic toxicity. Calculate the maximum total dose before dividing it between several blocks.
D. There is no need to aspirate before injecting, because no vessels run in the canal
The infraorbital artery and vein run through the canal alongside the nerve. Aspirate before injecting to avoid intravascular administration.
lightbulb Key takeaway
In cats and brachycephalic dogs the orbit lies very close to the infraorbital foramen and caudal maxilla. Use short needles, do not advance into the canal, always aspirate and adjust the total local anaesthetic volume to the cat's actual weight.
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Updated: November 1, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.