David Pretorius, [24 May 2025 at 13:13:59]: HI everyone, I have a direct request on the latest low opioid doses for nyala bulls and ewes and bushbuck rams and ewes? Any feedback possible? Hendrik Hansen, [24 May 2025 at 13:53:53]: Nyala bulls: Thianil 0.75 mg + medetomidine 6-9 mg + azaperone 10 mg Nyala ewes: Thianil 0.75 mg + medetomidine 4-6 mg + azaperone 10 mg Bushbuck: Thianil 0.5 + medetomidine 1-3 mg + azaperone 5-10 mg David Pretorius, [24 May 2025 at 14:21:36]: Dankie HH! Luis Amaral, [25 May 2025 at 07:53:36]: Working in the thick Eastern Cape coastal bush using telemetry, I give nyala bulls 3 mg Thianil + 4 mg medetomidine + 50 mg ketamine + 25 mg azaperone. For nyala ewes, I give 2 mg Thianil + 3 mg medetomidine + 40 mg ketamine + 20 mg azaperone. Down time is 3 to 4 minutes. For bushbuck, I also use telemetry systems: 2 mg Thianil + 2 mg medetomidine + 40 mg ketamine + 15 mg azaperone. Hendrik Hansen, [25 May 2025 at 08:03:52]: Thank you, Luis. Do they survive if you struggle locating then and find them 90 minutes later with that combination? Bossie Boshoff, [25 May 2025 at 08:05:25]: They wake up with the 3 mg Thianil + 4 mg medetomidine combination after 90 to 120 min on their own - probably due to lower alpha-2 complications. In the past, bulls were done with as high as 7 mg Thianil and 2-4 mg medetomidine. Both the Thianil and medetomidine are lower in the 3 + 4 combination, but the downtime is still low. They travel a shorter distance, probably because of the added effect of the ketamine in the combination also. Luis Amaral, [25 May 2025 at 14:18:56]: I agree with Bossie, I had some failures of the transmitters and still found them not too far and stable. With the telemetry, it is so much less stressful to find them. With the lower dosages, they go on a long way, and I battle to find them. Gernot Redeker, [25 May 2025 at 19:55:47]: In Namibia, nyala bulls will not go down with that. Maybe other Namibian vets can comment, but for bulls, I use 3-4 mg Thianil + 8 mg medetomidine + 20 mg azaperone to get them down, especially from a helicopter. Down-time is 4-5 minutes, and I kept them under immobilization for up to 60 minutes. For ewes, I use 2 mg Thianil + 6 mg medetomidine + 20 mg azaperone. Hendrik Hansen, [26 May 2025 at 6:04:18 AM]: Gernot, did you use the Thianil 0.75 mg + medetomidine 9 mg + azaperone 10 mg in nyala bulls at all? Gernot Redeker, [26 May 2025 at 7:40:38 AM]: Nope, never went that low, as using 1.5-2 mg they do not go down. So, I went up instead of down.... HO Reuter, [26 May 2025 at 07:52:26]: Hi Gernot, In small camps or boma darting from the ground, for big bulls, I use Thianil 1.5 mg + medetomidine 4.5 mg + azaperone 20 mg, and for ewes Thianil 1 mg + medetomidine 3 mg + azaperone 20 mg with good results. They take a while to stand or lie down, but are then nice to handle. I do not like darting nyala from helicopter, but of course this is often the only option. Darting from a helicopter, I have the following options: Bulls: Thianil 1.5 mg + medetomidine 6 mg + azaperone 20 mg, but also Thianil 3 mg + medetomidine 3 mg + azaperone 20 mg + ketamine 25 mg. Ewes: 1 mg Thianil + 4 mg medetomidine + 20 mg azaperone, but also 1.5 mg Thianil + 6 mg medetomidine + 20 mg azaperone. At the lower dosage rate, they take quite long, but shoe nice immobilisation / anaesthesia once standing / walking or going down. At higher dosage with ketamine, the downtime is around 4-5 min, but they go a bit too flaccid for my liking over time. Of course, pressure from the ground team and the pilots influence the decision to use higher dosage at times. Gernot Redeker, [26 May 2025 at 08:03:09]: Hi HO. For me 10-15 min down-time is too long, I am worried about them running for that time, especially nyala bulls. In my experience, they die when they take long to go down. That is why I decided to get them down fast. Hendrik Hansen, [26 May 2025 at 08:10:54]: I still think that the excitation of the opioid receptors with a higher opioid dose suppresses the alpha-2 agonistic effect. One needs to find the sweet spot (balance) of the potentiating effect to get an acceptable induction time and acceptable physiological parameters. This sweet spot isn't always a higher or more potent opioid. A lower induction time might put the animal that you can't find at risk. Balance is the answer and each and every veterinarian differs on where he wants that balance to be. The terrain time of year, capture team etc. also dictates the balance. As the adage goes, sometimes less can be more. Gernot Redeker, [26 May 2025 at 10:05:10]: Thank you HH. I agree, every situation and every vet needs to find what works the best. I do not know what terrain you guys are working in, but I personally will never put a dart into an animal if I cannot keep sight of it. To find a darted animal 90 min later will not work for me. That is my approach to darting and the safety of the animal. HO Reuter, [26 May 2025 at 10:23:12]: I agree a down-time of > 10 min is too long. I used to aim for 3-4 min with the old regime. With medetomidine combinations, I generally aim for 6-7 min downtime from a helicopter. Due to a less pronounced excitatory phase, they often run less than with the old regime but are less predictable and more difficult to guide / herd by chopper, but there is the added option to herd / walk on foot. The benefit of medetomidine mixes provides more options for different scenarios, than a one dose fits all scenario. To find the correct balance of potentiating effects of the drugs, chopper time, and safest anaesthesia remains a challenge. Ulf Tubessing, [26 May 2025 at 15:16:07]: I also use dosages in Gernot’s range, but I use 10 mg WBP (water-based perphenazine/perphenazine hydrochloride) in the dart. They are generally down in 3-5 min or easily handled. I have seen no problems with them being too flaccid or too active. Luis Amaral, [26 May 2025 at 19:21:45]: Gernot, add the ketamine and you will see a major difference. Christiaan Blignaut, [28 May 2025 at 06:16:46]: Good morning, if I need to travel with a sedated nyala bull for 20 min, will you still use this protocol and top-up with ketamine or is there a better way? (This is due to transport challenges) Hendrik Hansen, [28 May 2025 at 11:41:42]: Christiaan, this is very safe. I will easy keep a nyala sedated for extended period on this - no need to top up with ketamine. Effective sedation is present for 90 mins. I don't use the ketamine for nyala, and that is why I asked Luis about the ketamine for longer periods, because I don't know. I would be happy to keep the animal sedated at the above-mentioned dose. For transport in a crate, I only antagonise the Thianil with naltrexone, and don’t antagonize the medetomidine - the medetomidine and azaperone will give a very good tranquillisation for transport up to 8 hours after reversal. This dose is however not enough to load bulls together. Christiaan Blignaut, [28 May 2025 at 14:25:31]: Thanks! I will give it a go.
