For veterinary professionals
November 2, 2026
Ketamine shows up in most of my rabbit anesthetics, either in the premedication or as a co-induction agent with propofol. Part of the reason is analgesia. Part of it is the assumption that ketamine's sympathetic support offsets some of propofol's vasodilation.
That second part is a reasonable assumption borrowed from dogs and cats. Fukuzaki and colleagues tested it in rabbits with echocardiography, which is more than most induction studies bother to do.
This was a randomized, blinded trial in 22 healthy male New Zealand White rabbits. All rabbits were premedicated IM with dexmedetomidine 5 µg/kg, butorphanol 0.5 mg/kg, and midazolam 0.3 mg/kg.
Induction was propofol given at 3 mg/kg/min to effect, either alone or with dextroketamine 2 mg/kg. The authors measured mean arterial pressure and used echocardiography to look at systolic function and cardiac output.
MAP dropped in both groups, but less when dextroketamine was added. With propofol alone, MAP went from 76 to 66 mmHg. With propofol and dextroketamine, it went from 70 to 65 mmHg. The group by time interaction was significant, though only just (p = 0.049).
Echocardiographic systolic function and cardiac output were preserved in both groups. No group did meaningfully worse on the heart itself.
Honestly, not a lot, and that is a useful answer.
The difference in MAP between groups was a few mmHg in healthy young rabbits, and the baseline values were not identical. On average, neither group dropped into what most of us would call hypotension during induction. The ketamine group simply started lower and fell less.
What the study does support is that a ketamine co-induction does no apparent harm to cardiac function in premedicated rabbits, and it may blunt the propofol-related pressure drop a little. If you already use ketamine at induction for its analgesic and propofol-sparing value, keep doing it. If you don't, this paper alone is not a strong reason to start.
Randomization, blinding, and echocardiographic data make this a cleaner study than most rabbit anesthesia work. Using a realistic, commonly used premedication protocol also helps.
The limits matter for clinical patients:
For a healthy rabbit having a spay or a dental procedure, I would not change much. Ketamine as part of premedication or co-induction stays in my protocol because of its analgesic and anesthetic-sparing effects, and this paper reassures me it isn't costing the heart anything.
For the sick rabbit, the bigger lever is still preparation. Correct volume deficits before induction when the case allows it. Give propofol slowly and to effect, since rate matters as much as the total dose. Have blood pressure monitoring on before induction, not after. A hypovolemic rabbit at induction is a much bigger risk than the choice of co-induction agent.
Fukuzaki LM, Sprengel HZ, Vila BD, et al. Cardiovascular and echocardiographic effects of propofol induction, with or without dextroketamine, in healthy premedicated rabbits: a randomized study. Vet Anaesth Analg. 2026;53(6):101332. doi:10.1016/j.vaa.2026.101332
If you have a high-risk rabbit coming up for anesthesia, or want to talk through co-induction, CRIs, or blood pressure support, reach out to Dr. Kopp personally. Dr. Kopp is Nashville's exotic companion mammal specialist and a Fellow in Companion Animal Pain Management, and is happy to consult on cases or see referrals. See the referral information for veterinarians, or call Dr. Logan Kopp at Priest Lake Veterinary Hospital, (615) 361-4646.
This content is for educational purposes for veterinary professionals. It doesn't establish a VCPR or replace clinical judgment for an individual patient. Drug use and doses should be checked against current references and adjusted for each case.