Chronic phalaris toxicity in eastern grey kangaroos (Macropus giganteus)

Abstract

The combination of clinical signs and obvious neuronal pigmentation is consistent with chronic Phalaris spp. toxicity, a condition well documented in domestic ruminants.

Plant poisoning leads to alpha-synucleinopathy and neuromelanopathy in kangaroos

“…However, it is believed to be high in certain Australian regions following exposure to Phalaris-rich pastures (El-Hage, unpublished work, 2017). Phalaris staggers was also reported in red kangaroos ( Macropus rufus ), wallabies (Munday, personal communication cited in 22 ), western grey kangaroos ( Macropus fuliginosus fuliginosus ) and Tamar wallabies [( M. eugenii; Philips, unpublished work, 1984 cited in 22 )]. Bacci and colleagues described the syndrome in seven eastern grey kangaroos ( Macropus giganteus ) grazing Phalaris pastures 22 .…”

“…Phalaris toxicity (PT) affects animals at pasture, most commonly sheep but cattle and horses can also be susceptible to the Phalaris-derived toxins following ingestion of various Phalaris spp such as P. aquatica 12–19 . PT has been reported since the 1940’s with a worldwide prevalence 12,17,20,21 and occurs in grazing animals characteristically during a prolonged period of dry weather that precedes rainfall 22 . Because these are widely cultivated perennial pasture plants, over many decades phalaris toxicity in livestock has been important in Australia, New Zealand, South Africa, USA and Norway 23 .…”

“…PT can manifest as a ‘sudden death’ or as a ‘staggers’ form 24 ; and the clinical presentation of the former is described as either neurologic or cardiac 22,24 . Staggers, which affect gait and locomotion of affected animals is further subdivided into an acute reversible or the more common lethal chronic form (also called Phalaris staggers) 24 .…”

In this issue – December 2014

“…This article reports a case of toxicity in seven eastern grey kangaroos grazing pastures including Phalaris spp. in Victoria . Phalaris spp., or canary grass, is used commonly in south‐eastern Australian grazing systems and toxicity has been reported in various grazing livestock species, particularly sheep.…”

“…in Victoria. 8 Phalaris spp., or canary grass, is used commonly in south-eastern Australian grazing systems and toxicity has been reported in various grazing livestock species, particularly sheep. All kangaroos showed neurological deficits characterised by ataxia, head tremors and collapse.…”