Case reporUGevaiverslag

SUSPECTED CYCAD (CYCAS REVOLUTA) INTOXICATION IN DOGS

C J BOTHA *, T W NAUDE*, G E SWAN*, MARCELLA M ASHTON* and J F VAN DER WA TEREN*

ABSTRACT sheep in Australia is well known and has Three dogs which ingested part of the stem of a Japanese cycad (Cycas been reported widely34. There are 2 distinct syndromes, viz: acute severe revoluta) vomited repeatedly within hours after ingestion, showed marked gastro-intestinal disturbance and liver depression, severely congested mucous membranes, increased thirst and necrosis; and chronic partial paralysis. In profuse salivation. Subsequent haematological and blood chemical cattle the latter is better known and is investigation revealed elevated serum concentrations of alanine caused by degenerative lesions in the transaminase, an initial mild lymphocytopenia, thrombocytopenia and a spinal cord that lead to posterior ataxia, leucocytosis. The dogs recovered uneventfully. commonly known in Australia as "wob­ bles", "rickets" or "staggers "234 '2. Key words: Cycas revoluta, Japanese cycad, dogs, Cycad poisoning, Nishida, Kobayashi and Nagahama as vomition, hepatotoxicity cited by Laqueur & Spatz5 isolated an azoxyglycoside from the seeds of Cycas Botha c.J.~ Naude T.W.; Swan G.E.; Ashton M.M.; Van der Wateren J.F. revoluta (Thunb.) and named the Suspected cycad (Cycas revoluta) intoxication in dogs. Journal of the compound cycasin. Later the same group South African Veterinary Association (1991) 62, No.4, 189-190 (En.) isolated new azoxyglycosides from C Depart-ment of Pharmacology and Toxicology, Faculty of Veterinary revoluta and named them neocycasins. Yagi & Ta~eral3 determined the Science, University of Pretoria, Private Bag X04, 0110 Onderstepoort, azoxyglycoside contents in various parts Republic of South Africa of C revoluta and reported that the pith contained slightly less cycasin than the seeds on a percentage fresh weight basis. Cycads belong to the order Cycadales of The cycads are popular garden shrubs in After ingestion, intestinal bacteria which 3 families are recognised: Cyca­ South Africa, but due to strict nature enzymatically convert cycasin to the daceae (with one genus: Cycas); Stan­ conservation regulations to protect the hepatotoxic and carcinogenic aglycone, geriaceae (with only a single species: indigenous cycads, the exotic cycads are methylazoxymethanol (MAM)9. MAM is )

1 Stange ria eriopus (Kunze) Nash) and frequently planted as substitutes. A fur­ the common aglycone of all the different 1

0 Zamiaceae (with 8 genera, including ther advantage of these exotic species is azoxyglycosides isolated from various

2 2 Encephalartos, Zamia and Dioon, that they grow faster than the indigenous cycad species • d e amongst others)6 10. The indigenous varieties. The only pubHshed report that we t a cycads of southern Africa are S. enopus The earliest and most well-known re­ could find of cycad intoxication in dogs, d 61O ( and 28 species of Encephalartos • cord of cycad toxicity occurring in South is the article published by Senior et alB.

r 7 • e In South Africa members of the genus Africa was reported by Reitz He ac­ Two dogs in Florida (USA) ingested h Encephalartos are also known as s counted his experiences in the eastern seeds of Zamia floridana and died. Both i l "broodbome" (literally bread trees), Cape Province during the Anglo-Boer dogs vomited persistently, and b

u Hottentot- or Kaffirbread' 10. The war (1899-1902) after the hungry Boer developed severe liver necrosis followed P indigenous tribes used the starchy pith soldiers ate the fruit (cone) of the "Hot­ by icterus and a haemorrhagic syndrome. e h from the stems or trunks of Encephalar­ tentots bread" (Encephalartos alten­ Recently we investigated a suspected t tos species to bake bread. The pith was y steinii): "I had not eaten any, and case of cyC'ad poisoning in dogs after b

removed from the stem, wrapped in an returning to the firing-line, after going to they ingested parts of the stem of Cycas d

e animal skin and buried in the ground for tie up some horses that had broken loose, revoluta (Thunb.). t a period of a month or 6 weeks to induce n I was astonished to find more than half Three Bull Terriers, a 3-year-old bitch a it to ferment partially' 10 12. The fibrous r our men groaning and retching on the and 2 of her offspring (a dog and bitch, g mass was then ground to a flour (meal or ground in agony, some apparently at 16 months old), uprooted and destroyed e c sago), mixed with water to a paste and their last gasp..... " Dyer states that the a potted exotk cycad, C revoluta n e finally baked or roasted' 10 II 12. species most likely to have caused this (Thunb.) (Fig. 1). They tore off the c i l Detoxification is probably due to particular outbreak was probably E leaves and chewed at the 30 cm

r fermentation and water-solubility of the e longifolius (Jacq.) Lehm.'. diameter, fibrous stem and ingested an d tox;in'o. Wells as cited by Dyer (1966)' (and unknown quantity of plant material. n

u personal communication 1991; Botanical Shortly after jngestion, the old bitch

y Research Institute, Pretoria) reported the started vomiting. The male subsequently, a

w death of 2 head of cattle in the Riebeeck­ ingested the vomitus (containing plant e t East district of the eastern Cape Province material) and then also started showing a in 1965. The autopsies by Rossiter (State signs of nausea and vomited repeatedly. G ;Departmeilt of Pharmacology and Toxicology, t Veterinarian, Regional Veterinary Labo- The other female started vomiting within e . paCuity of Veterinary Science, University of ratory, Grahamstown, 1965) showed that n P/Bag an hour of ingesting the material. The

i .,retoria. X04, 0110 Onderstepoort,

b l\.epublic of South Africa the forestomachs contained many seeds dogs then became depressed and pros­ a trated. They all salivated profusely and S Rece' of E. longifolius.

y ,ved: February 1991 Accepted: June 1991 Cycad or zamia poisoning in cattle and drank water repeatedly. b 189 d 0038-2809 Jl S.Afr.vet.Ass. (1991) 62(4):189-190 e c u d o r p e R Four hours after exposure, the dogs were thrombocytopenia and a leukocytosis. neutrophil left shift could denote an presented to the Department of Phar­ Increases in the serum concentration of inflammatory reaction and was also macology and Toxicology, Faculty of AL T and in the total white blood cell reported by the same authors. In addition Veterinary Science, University of Pre­ count were the most prominent changes they also described a severe coagulo­ toria. On clinical examination, both observed in all dogs. An increase in pathy with thrombocytopenia and a lymphopenia'. In this case the 2 females also developed an initial mild thrombocytopenia and lymphopenia.

ACKNOWLEDGEMENT We wish to thank Prof. F Reyers and personnel of the Section of Clinical Pathology, Department of Medicine for their valuable assistance and Mrs 0 Fourie of the Botanical Research Institute for identification of the plant.

REFERENCES I. Dyer R A 1962- L966 The cycads of Southern Africa. Bothalia 6: 405-515 2. Everist S L 1981 Poisonous plants of Australia. Angus and Robertson Publishers, London 3. Gabbedy B 1, Meyer E P, Dickson 1 1975 Fig. 1: An example of Cycas revoluta, Japanese cycad or sago palm Zamia palm (Macrozamia reid/ei) poisoning of sheep. Australian Veterinary 10urnal 5/: 303- females were marked ly depressed and immature neutrophils and a mild 305 4. Hall W T K 1987 Cycad (zamia) poisoning in the mucous membranes of all the dogs lymphocytopenia and thrombocy­ Australia. Australian Veterinary 10urnal 64: were severely congested. Although all topenia, in the female dogs only, also oc­ 149-151 the dogs had slightly elevated curred. The haemoglobin and mean 5. Laqueur G L, Spatz M 1968 Tox icology of temperatures, we concluded that this was corpuscular haemoglobin concentrations cycasin. Cancer Research 28: 2262-2267 probably caused by transport during the and monocyte counts showed only slight 6. Palgrave K C 1981 Trees of Southern Africa. C Struik, Cape Town heat of the day. The respiratory and heart deviations from the norm. 7. Reitz 0 1929 Commando: a Boer journal of the rates were within normal limits. All 3 Morton as cited by Senior et ai' Boer War (1969 edn). Faber and Faber. London dogs were treated with magnesium observed vomiting, lethargy, anorexia 8. Senior 0 F, Sundlof S F, Buergeh C 0, Hines S sulphate (Elvet Epsom Salts, Elvet) as a and increased thirst beginning 2 h after a A. O'Neil-Foil C S, Meyer 0 1 1985 Cycad laxative and were taken home. dog had ingested seeds of Dioon edule. intoxication in the dog. 10urnal of the American

) Animal Hospital Association 21: 103-109 The next day all 3 dogs were All clinical signs disappeared within 12 1 9. Spatz M, Smith 0 W E, McDaniel E G, 1 moderately depressed and their mucous h and no complications were reported'. 0 Laqueur G L 1967 Role of intestinal micro­ 2

membranes were still congested. The Following ingestion of parts of the stem organisms in determining cycasin toxicity. d Proceedings of the Society for Experi-mental e older bitch exhibited a tender abdomen of CyCQS revolUlQ, severe vomiting and t Biology and Medicine 124: 691-697 a on palpation. During the following days prostration occurred, but was not fatal in

d 10. Tustin R C 1977 The toxicity and carcino­

( their habitus and colour of the mucous this case and the dogs made an genicity of some South African Encephalartos r e membranes returned to normal and they uneventful recovery. The conception and species. MMedVet Thesis, University of h s all made an apparently uneventful birth of a still-born puppy with a cleft Pretoria. i l recovery. The young female showed pro­ palate to the young bitch subsequent to II. Walt 1 F, Breyer-Brandwijk M G 1962 The b u oestrus 18 d after exposure and was later exposure, is probably incidental. In view medicinal and poisonous plants of southern and

P eastern Africa. E & S Livingstone, Edinburgh - successfully mated. On Day 31 of of the known carcinogenicity of this e and London h gestation, pregnancy was confirmed by plant family, the exposed dogs will be t 12. 1963 Whiting M G Toxicity of cycads. y sonar scanning. On Day 60 of gestation closely observed for possible future Economic Botany 17: 270-302 b one stillborn puppy with a cleft palate development of neoplasms. 13. Vagi F, Tadera K 1987 Azoxyglycoside d e was born. The rise in serum ALT concentration contents in seeds of several cycad species and t n Haematological and blood chemical encountered is indicative of possible various parts of 1apanese cycad. Agricultural a and Biological Chemistry 51: 1719-1721 r investigations revealed elevated serum liver necrosis and is consistent with that g

e concentrations of alanine transaminase reported by Senior et aP. The increases c

n (ALT) , an initial mild lymphocytopenia, in the white blood cell counts with the e c i l r e d n u y a w e t a G t e n i b a S y b d e c 190 0038-22809 Tydskr. 5. Afr. vet, Ver. (1991) 62(4): 189-190 u d o r p e R