Richard Burroughs, 19 May 2025 Morning colleagues. This is a video that I have been sent by a colleague, Willem Dafue: “This adult rhino shivers, falls over and then stands up again, and looks completely normal within 5 seconds – almost as if these are epileptiform seizures. I have done post-mortem examinations on 2 such females this weekend. Lung pathology is noticeable. I have taken many samples, including for virus isolation, but need some advice.” Maaike de Schepper, 19 May 2025 Test for rabies? Ulf Tubessing and HO Reuter have encountered rabies in rhino in Namibia. Richard Burroughs, 19 May 2025 Yep, that occurred to me also. Possibly Shuni virus infection? Poor quality grazing and malnutrition, energy deficit, cold may all play a role? Ettienne Pieterse, [19 May 2025 at 13:34:24]: Any parasite burden noticed? Maybe cysts in spine/brain? Kevin Robertson, [19 May 2025 at 13:35:30]: Have you considered botulism? We had similar symptoms in warthogs here in south Texas close to the Mexico border and botulism was the cause - from food waste discarded by illegal immigrants it was suspected. Xander van Eeden, [19 May 2025 at 14:12:15]: Hi. I had a very similar case recently. Are they wild rhino or semi-intensive? Are they being supplemented? We used a shotgun approach. Johan Steyl mentioned they can show neurological signs with Clostridia, so I decided to treat sooner rather than later. I gave Dormicum for the neurological signs, Excede, Rimadyl and Kyrophos. The rhino was 100% fine the next day and the owners have not seen any other signs since then. Took blood for analysis, but since Prof Venter’s laboratory is not functional, we are not sure what to test for. There were no blood parasites visible, nor obvious signs of infection on blood smear examination. No fever was present. I hope this helps. Tremors, high stepping gate, hindlimb paresis, recumbent. This is repeated every 2-10min. The animal is perfectly normal in between the episodes. Nele Sabbe, [19 May 2025 at 14:16:25]: Hi. We had a few cases like that 4 years ago, did full autopsy, tested for all possible neurological viruses, toxins, bacteria, you name it! We never got an answer of a probable cause: they tested negative for everything we tried. We also had cases like this in 2014: same thing: we did post-mortem examinations on every animal, used different labs, we tested food and water sources, nothing came back as a possible cause. BUT: with heavy rain seasons - that is when you normally see those. Richard Burroughs, 19 May 2025 Thanks all. These rhino are semi-intensive, so although grazing is poor, they are able to supplement. I have sent your suggestions to Willem. Michelle Otto, [19 May 2025 at 18:16:15]: These are typical Clostridial symptoms. Contact me if you want more info. Scott Citino, [19 May 2025 at 18:20:03]: If these are intensively managed rhinos, consider the strongyle parasite Kiluluma sp. If there are large numbers of larva encysted in the large colon and if they are triggered to excyst all at once due to environmental cues or parasite treatment, neurologic signs like this and acute death can occur. The large colon becomes “leaky” and allows entry of toxins that normally are not absorbed, such as ammonia and endogenous clostridial toxins. We have seen this in our rhinos at White Oak. There often are no adult strongyles present in the lumen of the colon - faecal exams are normal. If you hold the colon up to light, you can see the encysted larva and excyst sites. This is most pronounced just distal to the cecum. In most of these cases, you will find minimal lesions elsewhere. You must sample this area of the colon to see lesions. Nele Sabbe, 19 May 2025 In my cases over the years: We did have some cases with those findings, but they didn't show those neurologic symptoms. The cases that showed those nervous symptoms, never were found with GI problems. This may be just coincidental, but I agree, this should be checked. The larvae do damage the colon that can be seen macroscopically We never had any of the cases tested positive for clostridial infections. Richard Burroughs, 19 May 2025 Thanks all, appreciated JW Eksteen, [20 May 2025 at 22:35:39]: Hello Scott. Thanks you for sharing your cases and knowledge as always. If you experience neurologic signs again like this in intensively managed rhinos, how would you diagnose Kiluluma sp. on the other rhinos in the same environment? How would you treat them – is there a preventative protocol on them all? Scott Citino, [20 May 2025 at 22:47:31]: I am highly suspicious of ammonia toxicity, so if we have more, we will try to get blood ammonia analysis done. Other than this, we only see the larva in the colon, so we are unable to diagnose antemortem. We have tested for everything possible. Currently we are doing continuous deworming with Strongid C which prevents development of the adults and contamination of the pastures. We also deworm with ivermectin 4 times a year or when we see ova. Moxidectin can cause the larva to excyst in large numbers and we have had deaths after using moxidectin. So far, this strategy has prevented further deaths from this syndrome for about 2 years. We have also created more pasture space to provide a dilution effect. It appears that we have a monoculture of this parasite in our white rhinos. Very worrisome! JW Eksteen, [20 May 2025 at 23:48:22]: Thanks. Are you using ivermectin powder in your ration? Treatments oid for a week maybe and at what dosage? Is there no disturbance of healthy bots? There are short clusters of neurological signs as in this video. Michelle Otto has lots of experience and has seen many cases – she did loads of post-mortem examinations and diagnosed Clostridial toxicosis. Would you approach similar cases by using a specially developed Clostridium vaccine and/or focus on parasite diagnosis and prevention? As I understand it, understood Clostridium toxicosis and Kiluluma sp. is not common finding in the wild. Any PCR tests available for strongyle parasite diagnosis in horses that can be used? Scott Citino, [21 May 2025 at 03:34:03]: We have not found any of the known Clostridial toxins in these cases and have only found Clostridium perfringens type A in the GI tract. We have used a multi-valent Clostridial vaccine and a Clostridium perfringens type A vaccine when it was available. We have genetically typed both the adult and encysted larva of the parasite. Many of the cases in SA have had end-stage sepsis with Clostridial organisms seen on blood smears - we have never seen this. I believe many of the cases in SA have involved Clostridium sordelli - we have never found this organism. We have obtained blood from a couple of rhinos as they were dying and the CBCs and chemistry profiles are essentially normal. Most are female rhinos, often with a calf on their side. They can be observed normal and grazing and 30 minutes later dead on their side, with the calf still nursing. We have been able to shotgun treat some with neurologic signs and pull them through. We use ivermectin paste for treatment. There are no bots in our rhinos. Joel Alves, [21 May 2025 at 06:59:11]: Scott, have they picked up anything on histopathology on those sections of the colon where the larvae excyst? Michelle Otto, [21 May 2025 at 08:29:36]: Most of the cases I dealt with came back as C. novyi (there were also a couple that also tested positive for C. sordelli) but there is so much cross over between the species and their respective types, I wouldn't be surprised if one of the C. sordelli was identified as a C. novyi or vice versa in some cases Scott Citino, [21 May 2025 at 16:00:00]: Inflammation was associated with the larva breaking out,
