Research Communication — Navorsingsberig

Vermeersiekte caused by burkei Harv. subsp. burkei var. hirtella Merxm. in the Northern Province of South Africa

C J Bothaa, T A Gousb, Mary-Louise Penrithc, T W Naudéa,d, Leonie Labuschagned and Elizabeth Retiefe

myofibres of the skeletal system, ABSTRACT diaphragm and oesophagus, as well as The 1st field outbreak of vermeersiekte induced by Geigeria burkei Harv. subsp. burkei var. foci of myocardial degeneration and hirtella Merxm. is reported. It is also the first recorded outbreak of this disease in the arid necrosis. sweet bushveld of the Northern Province of South Africa. The toxicosis was experimentally Vermeerbos (the common name for reproduced in a sheep following daily intraruminal administration of 2.5–5.0 g/kg dried, of the Geigeria) is reported to milled material for 18 consecutive days. Neither the sheep in the field outbreak nor be moderately nutritious15. Grosskopf6 the ewe in the experiment exhibited any signs of regurgitation of rumen contents (vermeer- stated that vermeerbos, in limited quanti- siekte). All developed only the stiff or paretic/paralytic forms of the disease. Serum activities of CK and GGT were slightly raised in clinically affected sheep (n = 11) during the field ties, appears to be an excellent feed for outbreak, and serum activities of AST, GLDH, GGT, LDH and CK increased in the ewe sheep, as it retains its protein concentra- dosed with the plant material. Analysis of dried, milled Geigeria plant material confirms that tion during winter, whereas that of this species is moderately nutritious. grasses rapidly decreases after the growing season. Key words: Geigeria burkei, paralysis, paresis, sheep, stiffness, vermeersiekte. Botha C J, Gous T A, Penrith M-L, Naudé T W, Labuschagne L, Retief E Vermeersiekte FIELD OUTBREAK caused by Geigeria burkei Harv. subsp. burkei var. hirtella Merxm. in the Northern During the end of winter (August 1996) Province of South Africa. Journal of the South African Veterinary Association (1997) 68(3): approximately 50 sheep in a flock of 200 97–101 (En.). Department of Pharmacology and Toxicology, Faculty of Veterinary Science, Dorpers on the farm Drielingbosch University of Pretoria, Private Bag X04, Onderstepoort, 0110 South Africa. (23° 17′ S, 29° 41′ E), near Bandolierkop in the Soutpansberg district of the Northern Province, exhibited listlessness, stiffness INTRODUCTION tion losses6. G. aspera is associated with in the hindquarters, lameness and lagging Vermeersiekte following ingestion of more localised poisoning on the highveld behind the rest of the flock. A decline in different Geigeria species is a major intoxi- of Mpumalanga and the northern Free their condition was also noticed by cation of small stock in South Africa. State10,11. Under experimental conditions the farmer and some animals became Geigeria ornativa is the most important G. burkei subsp. burkei var. zeyheri induced paretic/paralytic. Some sheep were cause of vermeersiekte in the dry vermeersiekte, although there is no unable to rise and remained in sternal or Griqualand West area of the Northern confirmed report of any natural field lateral recumbency. When sheep were Cape11,15. Vahrmeijer13 reported that during outbreak10. Various α,β-unsaturated-8- assisted to stand the limbs trembled and a 1929–1930 as many as a million sheep died sesquiterpene lactones have been isolated staggering gait was observed. Two weeks in Griqualand West. Kellerman et al.11 from different Geigeria species and are before the investigation the farmer insti- calculated the economic impact of plant implicated as the toxic principles2,10,11. tuted supplementary feeding consisting poisonings and estimated that in 1996 The toxicity of the 3 species mentioned of a salt and flowers-of-sulphur lick, maize monetary terms the annual loss due varies. It has been estimated that G. burkei stover and poultry litter. The farmer to vermeersiekte mortalities exceeds subsp. burkei var. zeyheri is 3 times and G. incriminated a small, green, herbaceous 6 million Rand. The economic loss could aspera 10 times more toxic than G. orna- bush as the cause of the paretic condition. be considerably higher, as vermeersiekte tiva6,10. Sheep in feeding experiments with On inspection of the camp and observa- is known to be an erosive disease that G. ornativa hay ingested the plant for tion of the animals it was noticed that the causes various production and reproduc- prolonged periods and clinical signs were sheep eagerly ingested the incriminated noticed only after 3 weeks6. Clinically, 4 herb (Fig. 1), which was the only greenery forms of the disease are recognised, available at the time. The plant was recog- namely regurgitation (‘vomition’), stiff- nised as a Geigeria species and was aDepartment of Pharmacology and Toxicology, Faculty of ness, bloat and paresis/paralysis10. Regur- collected and submitted for identification. Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110 South Africa. gitation is not a common finding, and The presence of Helichrysum argyro- sheep usually exhibit stiffness, particu- sphaerum in the camp was also noted. The bVeterinary Laboratory, Private Bag X2408, Louis Trichardt, 0920 South Africa. larly of the hindquarters, in the early farmer reported that the flock was moved 10,15 cPathology Section, Onderstepoort Veterinary Institute, stages of the toxicosis . Macroscopical 8 months previously to another farm, Private Bag X05, Onderstepoort, 0110 South Africa. lesions are usually absent, but a mega- Potgietersrand (23° 15′ S, 29° 43′ E), where dToxicology Section, Onderstepoort Veterinary Institute, oesophagus may be encountered in some the veld was trampled and the grazing Private Bag X05, Onderstepoort, 0110 South Africa. cases and sheep may die from a foreign sparse, although abundant green Geigeria eNational Botanical Institute, Private Bag X101, Pretoria, body pneumonia if rumen fluid is aspi- was present. The sheep grazed on this 0001 South Africa. rated10,11. Van der Lugt and Van Heerden14 particular farm for 4 months before being Received: April 1997. Accepted: July 1997. reported hypertrophy and vacuolation of returned to the present property. Blood

0038-2809 Jl S.Afr.vet.Ass. (1997) 68(3): 97–101 97 Laboratory trial A 1-year-old Dorper ewe, with a cannula fitted into the rumen, was housed in a concrete pen at the Laboratory Animal Facility of the Toxicology Section at the Onderstepoort Veterinary Institute (OVI). She had free access to water and was fed oats hay and a maize meal-based pelleted concentrate. During a 2 week adaptation period and throughout the experimental period, regular clinical examinations and ECG recordings (Ectromed) were performed. Before and during the trial, blood samples were collected twice a week from the jugular vein and submitted for determination of serum activities of glutamate dehydro- genase (GLDH), AST, GGT, CK and LDH. Dried, milled plant material collected from the field outbreak was administered via the rumen cannula on consecutive Fig. 1: Sheep eagerly ingesting Geigeria burkei Harv. subsp. burkei var. hirtella Merxm. on days (n = 18) according to the dosing a farm in the Northern Province. regimen presented in Table 1. Dosing ceased once clinical signs were observed. The ewe was weighed weekly and the intraruminal dose adjusted accordingly. A sample of the dried, milled plant material was also submitted for feed analysis.

RESULTS

Plant identification The incriminated plant was identified as Geigeria burkei Harv. subsp. burkei var. hirtella Merxm.7,12 (Fig. 2) by the National Botanical Institute, Pretoria.

Family

Common name Most probably also vermeersiekte- bossie.

Fig. 2: Geigeria burkei Harv. subsp. burkei var. hirtella Merxm. Description7,12 A several-stemmed perennial herb with a woody rootstock, forming a round bush, samples from 21 sheep, ranging from carboxylic ionophore antibiotic poison- semi-woody, 0.2–0.3 m tall. Stems densely severely affected (n = 11) to apparently ing, samples of the poultry litter (n = 2) covered with crinkled, whitish, multicel- healthy animals (n = 10), were collected were also submitted for thin layer chro- lular hairs, branching in upper part with from the jugular vein. The blood was matography (TLC) and calorimetric more than one branch from the apex of allowed to clot, the serum collected and analysis5. A necropsy was performed on a main stem, brownish. Leaves alternate, submitted for determination of aspartate sheep that was euthanased and samples sessile, linear, 20–50 × 0.5–1.5 mm, margin transaminase (AST), gamma-glutamyl of brain, lung, liver, spleen, kidney, heart strongly revolute, densely covered with transferase (GGT), lactate dehydrogenase and skeletal muscle including oesopha- glands and white, crinkled multicellular (LDH) and creatine kinase (CK) activities. gus were preserved in 10 % buffered hairs. Flower heads in axils of branches These serum enzyme activities were formalin and submitted for histopatho- with leaves involucrate. Involucre globose determined by an automated chemical logical examination. The tissues were to campanulate, 10–20 × 8–10 mm, 4- analyser (Technicon RA-1000 Analyser, routinely processed and stained with seriate, outer bracts long, leaf-like, appen- Technicon Instruments Corporation) haematoxylin-eosin (HE). A provisional diculate, inner bracts brownish, using the manufacturer’s methods and diagnosis of vermeersiekte was made and acuminate-lanceolate, margin in upper reagents, except LDH, where the plant material was collected, air-dried, part ciliate. Receptacle setose. Ray florets German-recommended method was milled and stored in a cold room (–6 °C) female, 8–10 mm long, yellow, deciduous. used (Boehringer Mannheim). To rule out for dosing trials. Disc florets 5–6 mm long, bisexual,

98 0038-2809 Tydskr.S.Afr.vet.Ver. (1997) 68(3): 97–101 brownish yellow. Achenes narrowly tur- binate, densely silky-strigose, 1.5 mm long. Pappus usually of 10 broad scales.

Habitat Grassland.

Distribution Pietersburg (2329 CD); Haenertsburg (2329 DD); Potgietersrus and Percy Fyfe Nature Reserve (2429 AA); Nelspruit (2530 BD); Barberton (2531 CC) (Fig. 3).

Autopsy findings The carcass was in good condition and gross lesions included mild anaemia, muscle pallor, dull, pale areas in the myo- cardium, moderate hydropericardium, brain oedema, enlargement and oedema of the mesenteric lymph nodes, severe lung oedema with petechial haemorr- hages, multifocal petechiae in the thymus, congestion of the spleen, kidney and liver and cholestasis. Microscopical examina- tion of the tissue samples submitted Fig. 3: Distribution of Geigeria burkei Harv. subsp. burkei var. hirtella Merxm. in the revealed multifocal hyaline degeneration Northern and Mpumalanga Provinces of South Africa. (n = known localities.) and some fragmentation of oesophageal and skeletal muscle. Myocardial lesions consisted of multifocal hyaline necrosis Table 1: Dosing regimen and body weight of the ewe during the laboratory trial. and myofibrolysis with mononuclear cell infiltration accompanied by mild intersti- Experimental day Body weight Dosing regimen tial fibrosis. Lung tissue was characterised by severe congestion, oedema and (kg) Dose Total dose per day Period dosed × emphysema, with accumulation of alveo- g/kg n (g) Day lar macrophages. 0 38.0 2.5 × 7950–6 × Serum enzyme activities 7 39.0 5 7 195 7–13 14 39.7 5 × 4 198.5 14–17a The serum enzyme activities of the clini- 20 36.9 —— — cally affected and apparently healthy 27 38.1 —— — sheep selected on the farm where the out- break occurred are presented in Table 2. aDosing discontinued after Day 17. Mean serum activities of CK and GGT were slightly raised in clinically affected sheep (n = 11). The clinical chemistry parameters determined for the sheep in Table 2: Serum enzyme activities of clinically affected and apparently healthy sheep during the experiment are presented graphically the field outbreak. (Fig. 4). Notable increases in AST, GGT, CK and GLDH activities were detected Enzyme Clinically affected sheep Apparently healthy sheep Normal valuea (n = 11) (n = 10) from Day (D) 10 and LDH activity raised _ _ conspicuously on D 13. x (SD) Rangex (SD) Range

Analysis of poultry litter CK (U/l 25 °C) 101.0 (34.34) 40–166 84.9 (27.3) 49–129 <21 The TLC screen for the presence of car- AST (U/l 25 °C) 57.82 (11.05) 41–83 55.3 (8.04) 41–69 <60 boxylic ionophore antibiotics in the poul- LDH (U/l 25 °C) 474.36 (80.04) 343–654 452.6 (32.12) 392–499 <530 try litter detected salinomycin. Following GGT (U/l 25 °C) 37.09 (6.43) 25–53 30.6 (4.32) 23–41 <32 quantification, using the calorimetric a method, the salinomycin concentrations Schmidt M, Forstner D 1986 Laboratory testing in veterinary medicine. Diagnosis and clinical monitoring. Boehringer Mannheim, Mannheim in the 2 samples of poultry litter were 19 and 21 ppm, respectively.

Experimental case D 14 which progressed to a severe stiff- forms of vermeersiekte. From D 19 loco- The ewe dosed with milled G. burkei ness, lameness and paresis on D 17 and motion improved. Throughout the subsp. burkei var. hirtella lagged behind D 18. The dosing was discontinued on experiment, no significant ECG abnor- the other sheep and exhibited stiffness in D 18 as the clinical signs observed were malities were detected and the habitus of the hindquarters and recumbency from considered to be the stiff and paretic the animal remained unaffected. During

0038-2809 Jl S.Afr.vet.Ass. (1997) 68(3): 97–101 99 Fig. 4: Clinical chemistry parameters of the ewe dosed with dried, milled plant material. the adaptation period and the initial 2 Table 3: Analysis (Weende) of dried, milled Geigeria burkei weeks of dosing the body weight of the Harv. subsp. burkei var. hirtella Merxm. animal increased. However, during the last week of dosing a 7 % decrease in body Macro-constituents % ‘As is’ weight occurred (Table 1). The ewe was considered fully recovered on D 27 based Moisture 10.60 on the disappearance of clinical signs, the Dry matter (DM) 89.40 return of chemical pathology parameters Ash 10.84 to baseline activities and an increase in Nitrogen 1.08 Crude protein 6.77 body weight. Crude fibre 29.83 Crude fat 1.01 Analysis of dried Geigeria plant Calcium 1.04 material Phosphorus 0.12 The results of the analysis of the dried, Metabolisable energy (ME) (MJ/kg) (Rum.) 8.50 milled plant material dosed are tabulated Nitrogen free extract (NFE) 40.95 (Table 3). A metabolisable energy value of Total digestible nutrients (TDN) 56.85 8.5 % and a crude protein value of 6.77 % denote a fairly good nutritional quality.

together. G. burkei subsp. diffusa (Harv.) G. aspera by its involucre, which is globose DISCUSSION Merxm. and G. aspera var. rivularis (J M or campanulate and not narrowly The morphological relationship of G. Wood & M S Evans) Merxm. are more or obovoid; its stems are usually simple burkei Harv. subsp. burkei var. hirtella less prostrate, whereas the other taxa are below and branched above, not tending Merxm. with related species and its erect, usually many-stemmed from the to branch from ground level. distinguishing characteristics are as base, as is G. burkei subsp. burkei var. Although there is experimental evi- follows7,12: G. burkei subsp. burkei var hirtella. The latter taxon is distinguished dence for the toxicity of G. burkei subsp. hirtella is characterised by its narrow, from G. burkei subsp. burkei var. burkei and burkei var. zeyheri10 this is the first con- revolute leaves, densely covered not only var. elata Merxm. in having the leaves firmed field outbreak of G. burkei subsp. with glands but also with white, multicel- more densely distributed along the stem burkei var. hirtella poisoning in southern lular hairs. Geigeria can be divided and in the lower stature. G. burkei subsp. Africa. The prevailing poor grazing condi- roughly into 2 main groups on basis of leaf fruticulosa Merxm. and G. burkei subsp. tions at the end of winter and the avail- structure. G. burkei, G. aspera Harv., G. fili- burkei var. zeyheri (Harv.) Merxm. are more ability of lush, green Geigeria might folia Mattf., G. ornativa O. Hoffm. and G. diffusely branched and the flower heads explain why the plant was so eagerly acaulis (Sch.Bip.) Benth. & Hook.f. ex Oliv. are smaller than those of G. burkei subsp. consumed by the sheep (Fig. 1). This & Hiern, for example, have long, linear, burkei var. hirtella. G. burkei subsp. valida is also the first recorded outbreak of narrow leaves, while species such as G. Merxm. and G. burkei subsp. burkei var vermeersiekte in the arid sweet bushveld pectidea (DC.) Harv. and G. obtusifolia L. intermedia (S Moore) Merxm. have the of southern Africa1 and emphasises that Bolus have much shorter and broader, leaves much more densely crowded along wherever this genus is grazed it should be elliptical leaves. G. filifolia and G. acaulis the stem and the flower heads are usually regarded as potentially toxic. are rosette plants (stemless), G. ornativa much larger than those of G. burkei subsp. Neither the sheep in the field outbreak occurs as rosette plants or as erect, burkei var. hirtella. G. burkei subsp. burkei nor the ewe in the experiment exhibited branched herbs with flower heads close var. hirtella can be distinguished from signs of regurgitation of rumen contents,

100 0038-2809 Tydskr.S.Afr.vet.Ver. (1997) 68(3): 97–101 but developed the characteristic stiff and disturbances, weakness and recum- K G R, Brink C v d M 1967 The structure of paretic/paralytic forms of the disease. It is bency4. However, the poultry litter vermeerin. A sesquiterpenoid dilactone generally accepted that not all clinically contained only an average of 20 ppm from Geigeria africana Gries. Tetrahedron 23: 4153–4160 affected sheep will develop typical salinomycin, which is within the range of 3. Basson P A, Kellerman T S, Albl P, Von 10,15 ‘vermeersiekte’ (regurgitation) , and 15–20 ppm recommended for use as a Maltitz L J F, Miller E S, Welman W G 1975 Dorpers are considered to be less growth promotant in ruminants8. Blindness and encephalopathy caused by susceptible when compared to breeds Results of the analysis of dried, milled Helichrysum argyrosphaerum DC. (Composi- 10 tae) in sheep and cattle. Onderstepoort Jour- such as Merino and Karakul . plant material indicated that the nutri- nal of Veterinary Research 42: 135–148 The sharp rise in serum AST, GLDH, tional quality of this particular Geigeria 4. Fourie N, Bastianello S S, Prozesky L, Nel GGT and LDH activities of the sheep in species is fairly good. This might explain P W, Kellerman T S 1991 Cardiomyopathy the experiment indicate hepatocyte and why the plant was so eagerly consumed of ruminants induced by the litter of poultry biliary damage. Increased AST and GGT by the sheep (Fig. 1). A crude protein fed on rations containing the ionophore antibiotic, maduramicin. I. Epidemiology, activities have also been observed in value of 6.77 %, crude fibre value of clinical signs and clinical pathology. sheep dosed with G. aspera (N Fourie, 29.93 % and metabolisable energy value Onderstepoort Journal of Veterinary Research Biocon Research Laboratories, pers. of 8.5 % was determined. Van Heerden et 58: 291–296 comm., 1997). Van Heerden et al.15 were of al.15 reported an average crude protein 5. Golab T, Barton S J, Scroggs R E 1973 the opinion that GGT and AST may be of value of 11.25 % and crude fibre value of Calorimetric method for monensin. Journal of the Association of Analytical Chemistry 56: diagnostic value in G. ornativa poisoning. 23.05 % for dried, milled G. ornativa (n = 171–173 The Dorper ewe dosed with the plant 2). Myburg and co-workers, cited by 6. Grosskopf J F W 1964 Our present material exhibited severe stiffness on Grosskopf6, analysed 84 samples of knowledge of "Vermeersiekte" (Geigeria Days 17–18, and the increased AST and G. africana (= G. ornativa) obtained from poisoning). Technical Communication no. 21. LDH activities observed could reflect Griqualand West and determined a mean Department of Agricultural Technical ± Services, Pretoria muscle damage, which was confirmed by protein percentage of 7.08 % ( 1.2) and 7. Hilliard O M 1977 Compositae in Natal. the rise in CK activity (Fig. 4). In the field mean fibre percentage of 28.82 % (±4.7). University of Natal Press, Pietermaritzburg outbreak, mean CK activity was slightly They also analysed 2 specimens of G. 8. Immelman A (ed.) 1996 Growth stimulants. higher in the clinically affected group (n = aspera and determined an average protein Index of Veterinary Specialities 34: 75–77 11) compared to the apparently healthy percentage of 6.51 % and crude fibre of 9. Joubert J P J 1983 Attempted prevention and treatment of Geigeria filifolia Mattf. poison- sheep (n = 10). A more substantial eleva- 27.5 %. Geigeria spp. are therefore nutri- ing (vermeersiekte) in sheep. Journal of the 10 tion in CK activity was anticipated, as the tious in small quantities , but become South African Veterinary Association 54: 255– sesquiterpene lactones are primarily myo- dangerous when they constitute a major 258 toxins. However, Joubert9 reported that element in the pasture. 10 Kellerman T S, Coetzer J A W, Naudé T W serum activities of CK, glutamic oxalo- 1988 Plant poisonings and mycotoxicoses of livestock in southern Africa (1st edn). Oxford ACKNOWLEDGEMENTS acetate transaminase (GOT = AST) and University Press, Cape Town GGT did not increase in correlation with We thank Prof. T S Kellerman (Toxicol- 11. Kellerman T S, Naudé T W, Fourie N 1996 the symptomatology during experimen- ogy Section, OVI) for valuable advice and The distribution, diagnosis and estimated tal G. filifolia poisoning in sheep, and Van permission to use their facilities, Mrs A R economic impact of plant poisonings and Heerden et al.15 reported no increase in Schultz (Toxicology Section, OVI) for mycotoxicoses in South Africa. Onderste- poort Journal of Veterinary Research 63: 65–90 serum CK activity despite the presence of performing the ECG recordings, Prof. F 12. Merxmuller H 1953 Compositen-studien III. muscle pathology in sheep with vermeer- Reyers and staff from the Clinical Pathol- Revision der gattung Geigeria Griesselich. siekte induced by G. ornativa. ogy Section, Faculty of Veterinary Science, Mitteilungen der Botanischen Staatssammlung Helichrysum argyrosphaerum (wild ever- Onderstepoort, for the determination of Munchen 7: 239–316 lasting) also occurred on the farm and can enzyme activities, Dr D B R Wandrag 13. Vahrmeijer J 1981 Poisonous plants of induce paresis/paralysis and amaurosis in (Department of Ethology, Faculty of southern Africa that cause stock losses. 3,10 Tafelberg, Cape Town sheep . Since this plant was not eaten Veterinary Science, Onderstepoort) for 14. Van der Lugt J J, Van Heerden J 1993 Experi- and none of the sheep were blind, the feed analysis and Mr D Visser (Veteri- mental vermeersiekte (Geigeria ornativa O Helichrysum poisoning was ruled out. The nary Laboratory, Louis Trichardt) for Hoffm. poisoning) in sheep. II: Histological sheep also received a supplementary technical assistance. and ultrastructural lesions. Journal of the ration that included poultry litter. The South African Veterinary Association 64: 82–88 carboxylic ionophore antibiotics are often REFERENCES 15. Van Heerden J, Van der Lugt J J, Durante E 1993 Experimental vermeersiekte (Geigeria present in poultry litter and may result in 1. Acocks J P H 1988 Veld types of South Af- rica. Memoirs of the Botanical Survey of South ornativa O Hoffm. poisoning) in sheep. I: An ionophore poisoning in ruminants, evaluation of diagnostic aids and an assess- 4 Africa no 57. Botanical Research Institute, especially maduramicin . In sheep, Department of Agriculture and Water Sup- ment of the preventative effect of ionophore poisoning causes skeletal and ply, South Africa ethoxyquin. Journal of the South African cardiac muscle damage with locomotory 2. Anderson L A P, De Kock W T, Pachler Veterinary Association 64: 76–81

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