Diagnosis of Anatoxin a intoxication commonly relies on morphological identification of toxin generating cyanobacteria in water or stomach contents as well as analytical confirmation for the toxin(s) in water, stomach contents and tissues. As is true for microcystins, methods for analytical confirmation for Anatoxins are not commonly available in veterinary diagnostic laboratories. Thus, blue green algal intoxication is probably under diagnosed.
In summary, blue green algal poisoning should be considered in cattle presented with acute episodes of liver and/or neurological disease.
These clinical signs are caused by microcystin and/or anatoxin toxin poisoning. Although these two classes of toxins are responsible for most cyanobacterial intoxications, there are other cyanobacterial toxins produced in fresh waters that potentially could cause toxicity with different clinical signs.
More information on health effects of blue green algae poisoning are online.
Source: Michigan Dairy Review