Each summer, farmers and ranchers take a gamble on the weather, hoping for an appropriate level of rainfall to water crops and cattle, and the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) is encouraging cattle producers to be vigilant during periods of drought or drought-like conditions.

Water deprivation

TVMDL said the most obvious method of mitigating cattle losses due to water deprivation is to ensure that they have access to clean and plentiful water sources.

To remain healthy in hot weather, a 1,000 lb. heifer may need to drink about 20 gal. of water daily, TVMDL said. The lack of rain may also lead to far less forage growth. In normal years, green forage may provide some of the daily water requirements for a grazing cow, but in drought years, forage becomes much drier, and the amount of water available from forage lessens.

To avoid water deprivation, TVMDL said producers should ensure that water is readily available to their cattle every day. Producers should also check pumps that draw water from wells and make sure troughs and tanks contain water. Ensure that nipple waterers in barns are working properly.

Avoid holding cattle in pens that lack water sources for long periods, and do not work cattle in the heat of the day, TVMDL said in its announcement.

Because cattle are creatures of habit, TVMDL said producers should make sure their cattle know where to find water. If their preferred tank or trough dries up, animals may ignore other distant watering points in their pasture.

When introducing cattle to new pastures, drive the animals to the troughs or tanks, and make sure weaned calves know where to find water. Watch cattle to ensure that they are drinking adequately.

Water/salt intoxication

According to TVMDL, when cattle become excessively dehydrated, sodium levels increase in all tissues, including the brain. If dehydrated cattle find water and drink too much too quickly, the liquid will rush to their brains. As pressure builds in the brains, cattle may develop instability or seizures or may die from what is known as water/salt intoxication.

Salt intoxication does not mean that the animal is getting an excessive load of salt but, rather, that the sodium concentration is increasing in the body because the animal is deprived of adequate water, TVMDL explained.

If cattle become dehydrated, they need to drink water immediately — but only in small amounts, TVMDL said. Let all cattle drink at once to create competition for the water. Then, repeat this several times, with 30 minutes between each watering, until their thirst is satisfied. Monitor water intake, and keep it gradual.

Poor water quality

Hot summer days take their toll on ponds and tanks. As water sources dwindle during a drought, water may become concentrated with salt and other inorganic materials, TVMDL said. Unpalatable water may cause cattle to avoid troughs or tanks, leading to deprivation and dehydration.

TVMDL said cattle producers should test water for high concentrations of sodium, calcium, nitrates, magnesium salts and sulfates. If concentrations are high, new sources of fresh water must be provided.

Warm, stagnant water may also encourage the growth of blue-green algae, some of which are toxic. The algae often concentrate on the downwind side of a pond.

Dead rodents, birds or fish along the downwind side of a pond may indicate the presence of blue-green algae that could harm cattle. However, the first indication of blue-green algae could be one or more dead cattle, TVMDL said.