If an affected animal is still alive 2 or 3 hours after consumption, chances are good that it will live. Under rare circumstances, a chronic cyanide toxicity can develop, which causes weakness and partial paralysis, but this is not a common occurrence. In the southwestern U.S., a syndrome affecting the urinary bladder and nervous system in horses has been reported after consumption of sorghum grasses. The disorder can also cause death. Johnsongrass, like other plant species, can accumulate toxic levels of nitrates, depending on fertilization practices.
Nitrates are extremely toxic and can also cause death, especially in cattle, sheep and goats.
Look in the section on oats for more discussion of nitrate poisoning. The signs of nitrate poisoning may be confused with cyanide poisoning. The clinical signs of cyanide poisoning tends to come on quite rapidly, and the animals may be found dead without much warning. If the animals are exhibiting toxic signs, call a veterinarian immediately. There is an antidote, but it needs to be given intravenously and within a few minutes of the onset of signs, and it is often impossible to get help in time.