HO Reuter, [30 Apr 2024 Good morning, I would like to get some advice on prevention and treatment of chronic frothy bloat in nyala, which seems to occur usually in drought years on a farm intensively breeding and farming with nyala. Due to limited natural browse / grazing availability they generally supplement feed with ad lib access to Feedmaster game pellets, and at times also lucerne or lucerne hay mixed. For most years and seasons this works well, but at times (for example at present following a poor rainy season), individual animals get bloated. The bloat responds to Docusol treatment by stomach tube, and also if given in water / sprinkled over game pallets in boma. But the nyala keep bloated and feed intake is reduced. Over time they lose condition and eventually die due to rumen stasis and starvation. Other than repeated Docusol treatment, can anyone recommend a management / feeding and treatment regime to prevent losses? At present two bulls with 34” horns are affected. Thank you for any advice HO Reuter, [02 May 2024 at 23:29:10]: Good evening, I’m back on the frothy bloat issue of nyala on a farm halfway between Okahandja and Otjiwarongo. The nyala get frothy bloat from time to time. This seems to occur usually in drought years shortly after the rainy season. Due to limited natural browse / grazing availability they generally supplement feed with ad lib access to game pellets, and at times also lucerne. For most years and seasons this works well, but at times (for example at present following a poor rainy season), individual animals get bloated. Since this does not occur for most seasons and years in spite of ad lib feeding, we suspect that the bloat in the nyala is not caused by game pellets or lucerne. We suspect wilted Tribulus terrestris (dubbeltjies) is causing the bloat, even though Tribulus poisoning is more commonly associated with photosensitivity issues causing ‘geel dikkop’ in sheep / goats, or prussic acid poisoning (cyanosis). Does anyone have experience with wilted dubbeltjies causing bloat and if so, how best to avoid this? Will sodium thiosulphate (Hypo) be effective in treating bloat if caused by Tribulus, or is Hypo only effective in reducing risk of prussic acid poisoning from wilted dubbeltjies? Thanks again for any comments/ experiences/ advice! Bart Gazendam, [04 May 2024 at 15:12:03]: Hi! What game pallets are they feeding? I can imagine ad lib game pallets changing the rumen pH and in combination with the lucerne, will perhaps make them more sensitive to bloat in general. Perhaps Dr Steyl can comment more. I personally have no experience with dubbeltjies, sorry! HO Reuter, [04 May 2024 at 21:49:51]: Thanks Bart! Interesting paper indeed, and as so often with science, the more we know, the more questions arise. It seems that bloat, even though so common, is really quite a complex syndrome with very many contributing factors, of which we seem to not understand all. I believe in the case of frothy bloat in the nyala I had posted about, one of the main contributing factors is ingestion of wilted Tribulus terrestris. (Wilted “Dubbeltjies" can cause frothy bloat in small stock, according to various sources). It seems that the amount and timing of ingestion, and possibly even from which area / camp plays a role, most likely a combination of specific climatic and environmental conditions, soil type / deficiencies all play a role? Following drought years, there is little other natural browse/ grazing available, and if Tribulus grew fast following a good rain shower, but then does not get follow-up rain, it wilts. This probably effects the level of protein, sugars, glucosides / saponins, and at the right time (wrong time for the animal), if enough is ingested, produces either frothy bloat (or more commonly “Geel Dikkop” in small stock). There are obviously also individual animal factors (stress, condition, feeding habits) and if enough other food is eaten to “dilute” the foam forming agents, the animals might not be affected, or only be sub-clinically bloated and recover. Those nyala that get full blown bloat (as all other ruminants) loose appetite, and therefore cannot be medicated in feed, and also do not seem drink enough water to get enough Docusol in. They become listless, loose condition, and I think their rumen flora gets totally disrupted, and rumen content becomes acidic? Even after dosing with Docusol and trying to get in enough follow-up doses of Docusol, change diet and medicate in feed, some of them just deteriorate, get rumen stasis and die. I darted the 3 worst effected bulls, gave 70 ml Docusol either by stomach tube, or injected into the rumen via left paralumbar fossa and then stomach tubed to also give Hypo, Biosin mix from Craig Shepstone, and feed-lime into the rumen. I also injected Excede, Finadyne, a good dose of Kyroligo and BCoBolic before immobilisation reversal. The 1st bulls started vomiting during the procedure, and did not get all the medication planned into the rumen, the third one did vomit post procedure after immobilisation reversal. I presume the vomiting was caused due to pressure from the rumen pushing up frothy stomach content, maybe after oesophageal sphincter was opened by stomach tube, or as the Docusol released gas from the foam? The owner mixed Louis Greeff’s recipe of chop, game pellets (from Feedmaster, mainly lucerne based, I think), and feed-lime (no molasses or cottonseed oil added, as not available on the farm) as a feed remedy. We kept the 3 bulls in the boma to avoid further ingestion of Tribulus, and facilitate in-water and in-feed medication. They add Docusol, and Hypo to the drinking water, and Biosin sprinkled over the mixed food twice daily. According to the farm workers (owner will only be able to get back to the farm tomorrow), the nyala bulls are looking a bit better and are taking in some of the food. Thanks, Louis, to your invaluable advice on feed mix, etc. once again!
