Production Animal Clinical Toxicology

Plants | Epidemiology | Pathogenesis | Clinical Signs | Necropsy | Diagnosis | Treatment

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Plants

• Anacystis cyanae
• Anabaena circinalis and other species

Epidemiology

plant/environmental factors

• conditions for optimal active growth of water bloom include:
• summer, autumn; drought conditions and low dam water levels
• water from heavily fertilised land, sewerage, stockyard effluent
• under these conditions tend to be increased in anaerobic bacteria which in turn increase P, N, Carbon Dioxide - with long sunlight, algae growth promoted on bottom
• gas production and algae rise
• wind concentrates bloom on one side which may force animals to drink contaminated water
• not all blooms toxic; those that are need also to be actively growing

Pathogenesis

• small cyclopeptides which cause rapid death
• bacteria associated with algae are thought to contribute to toxicity

Clinical Signs

• sudden death within 24 hrs of water consumption
• abdominal pain, nausea, vomiting
• dyspnoea
• convulsions, death
• if illness longer duration, icterus and photosensitisation will occur

Necropsy

• severe hepatic necrosis and haemorrhage
• serosal/mucosal haemorrhage alimentary tract

Diagnosis

• history
• presence of algae having characteristic strong odour

Treatment

• acute - none
• subacute - as for photosensitisation