The intoxication and death of cattle feeding on kikuyu grass has occurred sporadically in Australia, New Zealand and South Africa. The outbreaks have had a high morbidity and high mortality. In both New Zealand and South Africa, outbreaks of the disease seem to have occurred in association with a previous invasion by the army worm Spodoptera exempta.
Cultures of the moulds Myrothecium roridum and M. verrucaria when fed to cattle, have produced a disease almost undistinguishable from kikuyu poisoning as seen in the field in New Zealand. Moreover Australian investigators and others have isolated these latter moulds from kikuyu grass in association with outbreaks of poisoning.
Most outbreaks of kikuyu grass poisoning have occurred on sheltered pasture on sandy and volcanic soils. The outbreak is usually preceded by several days of warm weather and rain. The disease has been reported mainly from February to June with peak outbreaks in April.
The clinical signs usually develop after 2 - 3 days grazing on kikuyu grass. Anorexia and depression with salivation and severe thirst are seen. There are depressed rumen movements and dehydration is very severe with marked haemoconcentration. Animals may hang near water and "sham drink". The rumen may become distended and incoordination, particularly of the hind limbs is seen. This is followed by tetany and recumbency.
The main post mortem features include characteristic lesions of necrosis and reddening of the epithelium of the rumen, reticulum and omasum. The rumen is usually overloaded with sloppy ingesta.
There is no known effective treatment.
There is a high mortality.
Martinovich, D., Mortimer, P.H. and diMenna, M.E. (1972). Similarities between so called Kikuyu poisoning of cattle and two experimental toxicoses. N Z vet J. 20: 57 58.
Martinovich, D. and Smith, B. (1972). Kikuyu poisoning in sheep. N Z vet .J. 20: 169.
Martinovich, D. and Smith, B. (1973). Kikuyu poisoning of cattle. 1. Clinical and pathological findings. N Z vet J. 21:55 63.
Smith, B.L. and Martinovich, D. (1973). Kikuyu poisoning of cattle. 2. Epizootiological Aspects. N Z vet J. 21:85 89.
Surveillance (1974) 1(1): 7 Ingestion of salt water by cattle
Surveillance (1974) 1(2): 9 Kikuyu poisoning (cattle)
Surveillance (1975) 2(2): 10 Kikuyu poisoning (cattle)
Surveillance (1976) 3(3): 6 Kikuyu poisoning (cattle)
Surveillance (1979) 6(1): 12 Kikuyu poisoning (cattle)
Surveillance (1979) 6(3): 11 Kikuyu toxicity (cattle)
Surveillance (1980) 7(1): 10 Case notes