Water Management on Pastures: Blue-Green Algae Poisoning

Table of Contents

1. Blue-Green Algae Poisoning
2. Other Water Management on Pastures Recommendations
   • Water Requirements
   • Livestock Watering System Alternatives
   • Moving Water With Pump And Gravity Systems
3. Related Links

Blue-Green Algae Poisoning

Animals drinking from standing water in the summer are potentially exposed to poisoning by blue-green algae.

Long periods of warm weather and a high content of organic matter in slow moving or stagnant water can produce blue-green algae blooms. The algae produces a toxin that can cause chronic or acute poisoning.

Symptoms of poisoning develop very rapidly and resemble an allergic reaction. Animals are usually found dead at the water's edge or only a few metres away. In acute poisonings, the animal suffers from intestinal problems, internal bleeding and paralysis, leading to respiratory failure.

Small amounts of poison cause weakness and staggering. In some instances, apparent recovery from an attack is followed in a few days or weeks by evidence of photosensitization. There may be inflammation of the muzzle, the skin of the ear, the udder, or other parts of the body. Jaundice is often seen, and constipation is a common symptom. Such cases usually recover under good care.

Related Links

... on forages and pastures, visit Forages and Pastures (OMAFRA)
... on weed control, order Publication 75 Guide to Weed Control: Forage Crops
... on agronomy for field crops, order Pub. 811 Agronomy Guide for Field Crops: Chapter 3 Forages
... on field crop protection, order Publication 812, Field Crop Protection Guide
... on livestock, visit Livestock (OMAFRA)