A Poison Primer: Source and Symptoms

 Issue # 175 - August/September 1999

1. WATER CONTAMINATION

ALGAE

Occurs when dense bloom of blue-green algae produces potent neurotoxin.

Causes convulsions and sudden death in livestock, wildlife and birds.

Algae sampling and testing required to confirm poisoning.

SALT

Occurs when animal ingests high concentrations of salt or is deprived of water, especially in hot weather or in cold weather when water freezes.

Poultry, feeder pigs and ruminants are susceptible.

Blindness, deafness or paralysis may result.

2. SOIL IMBALANCES

SELENIUM

Occurs when livestock consume high selenium content in forage on alkali soil found on Great Plains of U.S., western Canada and Mexico.

In its most severe form, causes blindness and staggering. Can also cause cracked hooves and lameness.

Soil testing recommended for diagnosis.

MOLYBDENUM

Caused by imbalance in copper/molybdenum ratios in soil, most common in western U.S.

Ruminants, especially young cattle, are most susceptible.

Causes severe scours and emaciation.

3. FEED CONTAMINATION GOSSYPOL

Excess pigment found in cottonseed products causes cumulative toxicity.

Immature ruminants and pigs are most susceptible.

Prolonged exposure causes weight loss, weakness and loss of appetite.

AMMONIA

Caused by abrupt addition of feed-grade urea or ammonium salts to the ruminant diet.

Mature ruminants are most susceptible, as they convert nonprotein nitrogen to ammonia, which is toxic.

Causes muscle tremors, weakness, difficulty breathing and death.

MYCOTOXINS

Worldwide problem caused by ingestion of moldy feed or corn or certain varieties of mold-infected pasture grass and forage (e.g., fescue grass, rye, sweet clover).

All species of livestock, horses and poultry are susceptible.

Wide variety of signs are possible, including lameness, paralysis, listlessness, jaundice and internal bleeding.

Feed analysis required to confirm toxicosis.

FLUORIDE

Found in feed-grade phosphates, well water with high levels of fluorine or airborne factory waste.

Usually requires long-term exposure and results in abnormalities of the skeleton and teeth.