| Scott Fritz, DVM, ABVT Toxicologist Beef Cattle Institute Kansas State University Scottfritz@vet.k-state.edu |
Sources
Warm, stagnant, surface water, often with a mechanism of phosphorus and nitrogen loading. Algae may appear as a scum on the surface that resembles paint. These blooms are buoyant and often concentrate on the downwind side of ponds.
Mechanism
- Hepatotoxic algal toxins disrupt the microstructure inside hepatocytes resulting in acute, severe hepatocellular necrosis.
- Neurotoxic algal toxins cause a severe neuromuscular blockage.
Signs
The most common clinical signs observed is acute death. The neurotoxins produced by these algae are some of the most potent biotoxins known and can result in death in minutes. The hepatotoxic varieties are the most commonly-encountered in most places where cattle production occurs. Death from exposure often occurs in 24 hours. Clinical signs, if observed, are typically non-specific. Animals may only appear depressed which progresses to tachypnea with signs of abdominal pain and death.
Treatment
Due to the severe nature of the exposure, effective treatments have not been identified. Once animals show clinical signs, a lethal dose has likely been consumed.
Diagnosis
Identification of algae and toxins in water sources, histopathology of the liver.
Links
- https://ksvdl.org/resources/news/diagnostic_insights_for_technicians/august2020/blue-green-algae-season.html
- https://www.merckvetmanual.com/toxicology/algal-poisoning/algal-poisoning-of-animals#Key-Points_v54342456
- Fritz, S. A., Charnas, S., & Ensley, S. (2024). Blue Green Algae. Veterinary Clinics of North America: EquinePractice, 40(1), 121-132. doi:https://doi.org/10.1016/j.cveq.2023.10.006
