Drought and Livestock Health

Some areas of Pennsylvania have experienced a prolonged dry spell. Livestock owners should be alert for special problems that can occur during a drought.

OVERHEATING: All animals can overheat in hot weather, especially if they lack adequate water. Animals at special risk are: working animals (draft animals and horses being exercised); very young animals; very old animals; and freshening (farrowing, lambing, or foaling) animals. Watch for rapid, shallow breathing and reluctance to move. If rectal temperature is over 105 degrees, apply cold water by hose or wet burlap bags. Get veterinary help fast! Shade and moving air go a long way toward avoiding heat stress.

LACK OF WATER: When streams dry up, wells go dry and pond water becomes unappealing, livestock can suffer from lack of water. Giving too much water all at once to water-deprived animals can cause edema, nervous signs, and red-colored urine. Check water supplies frequently. Supply supplemental water if pasture supply is doubtful.

BLUE-GREEN ALGAE: This type of algae can overgrow in a stagnant pond, particularly during hot, dry spells, and can be poisonous if livestock are forced to drink much of it. If ponds can be aerated, do so. If not, it may be necessary to fence off the pond and offer another source of water if algae bloom on the pond is heavy.

POISONOUS PLANTS: Weeds and toxic plants may be the only green things out on the pasture. Livestock ordinarily avoid these plants, but they may be forced to eat them during a drought. Survey your pastures at least weekly for edible materials. Feed supplemental roughage during short-grass times. Clip pastures to keep noxious and toxic weeds under control.

NITRATE ACCUMULATIONS: Annual weeds, sudan grass, corn and small grains can have high levels of nitrate content under drought conditions. Drought, followed by a rainfall, allows very high uptake of nitrate in plants. Use caution if these plants are grazed or green chopped under these conditions.

If in doubt about the nitrate level of a forage, the suspect material can be tested. Your county extension office has information on nitrate testing and interpretation of these results.

To minimize the adverse effects of heat and drought:

* Provide shade and air movement, particularly during the heat of the day.
* All livestock need access to salt and water. Provide a clean, algae-freesource of water readily accessible to the animals at all times.
* Almost all pastured livestock need supplemental feed during a drought.
Author: Larry Hutchinson, Extension Veterinarian

Larry Hutchinson, Extension Veterinarian
Department of Veterinary Science
Penn State College of Agricultural Sciences
115 Henning, University Park, PA 16802-3500