Christopher Anthony Bourke

Sporadic or idiopathic Parkinson’s disease is a movement disorder with a worldwide distribution, a long pre-clinical latent period and a frequent association with dementia. The combination of molybdenum deficiency and purine ingestion could explain the movement disorder, the distribution, the latent period and the dementia association. Recent studi...

Amyotrophic lateral sclerosis (ALS)–motor neuron disease (MND) is divisible into 6 familial and 10 sporadic syndromes (1). Familial syndromes are also recognized in animals, namely, dogs, cattle, rats, and mice. This article is concerned with the most common form of ALS, sporadic Charcot ALS (SC-ALS). This form is of particular interest because it...

Background An astrocyte-associated motor neurone syndrome was produced in molybdenum-deprived sheep fed xanthosine. Mo-deprived sheep fed inosine, adenosine or guanosine would be also expected to develop astrocyte-associated motor neurone syndromes, because all these purine nucleosides can act as neuromodulators and all depend on the Mo-associated...

The occurrence of Tribulus terrestris motor neurone disease (MND) in sheep is linked with grazing Tribulus growing on cultivation paddocks. A previous survey found that the molybdenum (Mo) content of Tribulus growing on uncultivated soils in the Coonabarabran district of New South Wales was 3.03 ppm, but on cultivated soils it was <0.04 ppm. Tribul...

Profiles of volatile secondary metabolites (VSM) in Mediterranean and Con-tinental Festuca arundinacea, either endophyte free or infected with the fungal endophyte Neotyphodium coenophialum strain AR542, were determined using gas chromatography– mass spectrometry (GC–MS). The profile of VSM in the endophyte-free Mediterranean F. arundinacea germpla...

A new form of toxicity called equine fescue oedema is described. The clinical signs included inappetence, depression, and subcutaneous oedema of the head, neck, chest and abdomen. Affected horses had very low plasma albumin values. The toxicity affected 48 of 56 horses on six farms in different states of Australia, and 4 horses have died. All horse...

Fenugreek staggers has occurred in sheep in Victoria, as both an acute and a chronic syndrome. Signs included quadraparesis, a high stepping fore limb gait and a 'bunny-hopping' hind limb gait. Changes consistent with acute oedema were found in the brain and spinal cord of acute cases, and Wallerian degeneration in the peripheral nerves of chronic...

There have been anecdotal reports since 1962 of 'staggers' in sheep grazing Romulea rosea infested pastures, but this is the first detailed account. In September 2005, a locomotor disorder developed in 12 of 120 Merino wethers that had grazed R. rosea infested pasture at Albury, New South Wales, over several months. Affected sheep displayed signs t...

Fusarium torulosum was isolated consistently from the leaves of kikuyu plants collected from a pasture near Maitland, NSW, on which grazing cattle had been affected by kikuyu poisoning. This fungus is known to produce the toxins wortmannin and butenolide, both of which can produce clinical signs and pathological changes similar to those exhibited b...

To observe the clinical signs of sheep affected by Tribulus terrestris motor neuron disease, to ascertain their response to striatal dopamine reducing drugs, and to examine their brains and spinal cords for microscopic changes. Twenty-eight sheep displaying well developed clinical signs of the disorder were observed. Twenty-two of these and 22 norm...

The fruit of the plant Tribulus terrestris is well known as a traditional Chinese medicine with a myriad of reported uses. Herbal medicine preparations are becoming available for many uses including body building and for stimulating spermatogenesis and libido. In addition, the whole live plant causes significant sheep losses in certain regions of A...

To investigate the clinical effect of administering sufficient Hypericum perforatum to cattle to deliver quadruple the reported oral toxic dose. Thirty-six yearling Hereford (n = 18) and Angus (n = 18) steers. A series of six experiments was conducted, each using 12 animals in a 2 x 2 factorial design, with two breeds of cattle (Hereford, Angus) an...

The alkaloid tribulusterine, first obtained from the fruit of Tribulus terrestris L. and considered to be 1-[(3-hydroxymethyl)-2-furyl]-9H-pyrido[3,4-b]indole, has been shown by synthesis and spectroscopic analysis to be the (5-hydroxymethyl)-2-furyl analogue. This is the known β-carboline alkaloid, perlolyrine. The synthesis of the 3-hydroxymethyl...

To determine the rectal temperature response of cattle, following the oral administration of ergot of rye (Claviceps purpurea), under pen conditions of enforced sunlight compared with those of enforced shade. Hereford cross steers were divided into two groups of 18. One group was dosed once, on a Monday morning, with finely ground rye grass ergots...

To investigate the roles of shade, fleece length and wool type in the protection of sheep from Hypericum perforatum poisoning. Adult Merino ewes of superfine, fine and medium wool type. Seventy sheep were divided into seven equal groups. During late spring and summer a series of successive, replicate experiments was conducted, each using one group...

Hypericin and pseudohypericin, bioactive constituents in St. John's Wort (Hypericum perforatum), have been determined in the soft tops of the plant that are most likely to be browsed by foraging livestock. In two consecutive seasons, the hypericin/pseudohypericin concentration in a broad leaf biotype varied from a winter minimum of less than 100 pp...

To assess the usefulness of rectal temperature responses in Australian bred Merino sheep, following the oral administration of Hypericum perforatum (St John's wort), as an early indicator of Hypericum intolerance. Thirty-three Merino ewes were divided into three groups of 11. Each group was dosed with finely ground, dried, flowering growth stage H...

To assess the validity of claims that heavy metal contamination from an open-cut mine caused the death of 226 cattle on a nearby farm over a period of 18 months, and to investigate other possible contributing factors. A retrospective assessment of previous investigations combined with additional chemical analyses. Extensive chemical analyses produc...

A new locomotory disturbance of cattle is described. The condition has occurred sporadically since the mid-1980s. Affected herds had all grazed flood plain pastures in a restricted area of north-western New South Wales. Calves were either born with clinical signs or developed them by 4 months of age. The disease was characterised by a slowly progre...

Many of the nervous and muscular locomotor disorders that affect sheep throughout Australia are commonly referred to as ‘staggers’ syndromes. The range of clinical signs displayed by sheep suffering these disorders is sufficiently diverse to enable each syndrome to be graded into one of 5 progressive clinical groups. The first group, the limb pares...

Fresh, mature, ungrazed Tribulus terrestris plant material was subjected to a standard alkaloid extraction procedure. The extract was fractionated by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). Two major alkaloid fractions were demonstrated. These fractions were identified by means of TLC, ultraviolet spectrof...

Twenty outbreaks of Phalaris aquatica "sudden death" syndrome in sheep were investigated between 1981 and 1991. Four were confirmed and one was suspected, to be a cardiac disorder; 5 were confirmed and 3 were suspected, to be a polioencephalomalacic disorder; the aetiology of the remaining 7 outbreaks could not be determined. Potentially toxic leve...

The clinical signs displayed by 96 sheep affected by the nervous syndrome of Phalaris aquatica toxicity and 10 normal sheep injected intravenously with the phalaris alkaloid, 5-methoxy dimethyltryptamine (dose range 0.01 to 5.0 mg/kg), were observed. The distributions of phalaris indole-like cytoplasmic pigments in nuclei of the brains and spinal c...

The beta-carbolines harmane, norharmane, tetrahydronorharmane, harmine, harmaline and harmol were administered to sheep to assess their effects on upper motor neurone function. Harmane at a dose rate of 54 mg/kg induced hypomotility, head tremors, pelvic limb paresis, hypermetria and a wide based stance. A range of similar effects were observed wit...

The acute toxicity for sheep of 3 alkaloids that occur in Phalaris acquatica was examined by intravenous and oral administration. The lowest tested dose rates that produced clinically observed signs were, for 5-methoxy dimethyltryptamine, 0.1 mg/kg body weight intravenously and 40 mg/kg orally; for gramine, 10 mg/kg intravenously and 500 mg/kg oral...

A unique mixture of toxic tunicaininyluracil antibiotics, closely related to the corynetoxins which causc annual ryegrass toxicity and to the tunicamycins, has been identified in rain-damaged, stored wheat implicated in a fatal intoxication of pigs. The toxins, present at a level of approximately 4.5 mg per kg, were isolated by preparative t.1.c. T...

An investigation was carried out into the pathogenesis of a unique locomotory disorder of sheep. Thirty sheep which had exhibited clinical signs for more than 15 months were examined for the presence of muscle atrophy, limb paresis, and spontaneous rotational behaviour. A single large dose of levodopa was administered to 12 normal and 12 affected s...

The history of an unusual locomotory disturbance of sheep is traced from its first recognition in 1937 through to the most recent outbreak in 1981-83. The condition occurred only at certain times and in restricted areas of the central and northern slopes districts of New South Wales. Outbreaks were repeatedly associated with drought periods during...