Think you’ve got sick cattle? It’s time to play DARTs

Thursday, June 15, 2017

It is relatively easy to determine when a dependent child is sick as they often just tell you or moan pitifully, but what about livestock who are dependent upon cattle producers to correctly ascertain their well-being? It can be tough to tell a moo from a moan.

“One way to do it is to use the D-A-R-T system, an acronym that literally helps producers to keep in mind likely tell-tale signs of poor animal health,” said Barry Whitworth, veterinarian and Oklahoma State University Cooperative Extension food animal quality and health specialist.

The letter “D” stands for depressed.

“Initially the signs can be quite subtle, such as droopy ears or perhaps the animal carries its head a little lower than others in the same group,” Whitworth said. “As a sickness progresses, many animals will separate from the herd and may lie around a lot because of soreness.”

The letter “A” stands for appetite. This one is fairly obvious: sick animals typically don’t like to eat so if a producer has an animal that is off its feed, chances are there is a health-related issue.

The letter “R” stands for respiration. Cattle will generally take about 10 to 30 breaths per minute.

“Producers should see an inspiration, expiration and a pause that should all take about the same amount of time,” Whitworth said. “Increases in the time period for inspiration or expiration are clues something is wrong.”

Another clue is an animal that is breathing with its mouth open. Whitworth recommends looking at the animal’s nasal passages to make sure they are clean and the animal’s eyes to ensure they are clear of any discharge.

“Another obvious one is listen for noises when the animal is breathing,” Whitworth said. “Any one or combination of these is a tipoff there is an issue in the animal’s respiratory tract.”

The letter “T” stands for temperature. This one can take a bit more labor to verify as it is tough to take an animal’s temperature out in the pasture.

“If you have these animals up, however, look for a temperature that is probably 103.5 to 104 degrees or above,” Whitworth said. “Also, take the animal’s temperature as early in the morning as possible. By late afternoon on a hot summertime day, the animal’s temperature is normally going to be a bit higher anyway.”

The ‘beef’ on possibly fatal health issues

An operation with sick cattle is obviously not in a good place, and may potentially be skirting disaster if the cause of a sickness is not determined quickly and accurately.

If possible, OSU’s Division of Agricultural Sciences and Natural Resources recommends any animal that dies suddenly from unknown causes to have a thorough necropsy done by a veterinarian, who may forward diagnostic submissions to the Oklahoma Animal Disease Diagnostic Laboratory on OSU’s Stillwater campus.

“There are any number of health issues that can result in animal fatality, with some of the more common causes being anaplasmosis, nitrate or prussic acid poisoning and even blue-green algae toxicity,” said Marty New, OSU Cooperative Extension area livestock specialist headquartered out of Duncan.

An infectious disease, anaplasmosis is caused by a parasite that attacks the red blood cells of cattle. Infected cattle will become anemic, feverish and may die. Subtle symptoms include getting tired quickly. If an animal wants to lay down or lag behind the herd while being moved check their mucous membranes – gums or vulva in cows – to see if they are pale.

“Anaplasmosis affects adult cattle more than calves,” Whitworth said. “In some cases it can cause abortion or weak calves in heavy bred cows. Typically, animals die one or two here and there, a few days apart.”

It is diagnosed by using a blood smear. Given a producer’s investment, all cattle found down but still alive should have a blood smear taken. Blood samples can indicate if the problem is only with the individual animal or might affect others in the herd.

“Oklahoma producers should always be mindful of the possibility of nitrate toxicity affecting their cattle, and know the conditions under which it is more likely to potentially become a problem,” New said. “Plant species vary in their ability to accumulate nitrate. Even common barnyard weeds can cause problems.”

If nitrate accumulation is of concern, select sources of feed that have lower accumulation potential. Consider the environmental conditions and manage inputs to accom­modate lower accumulation potential.

Stalks are highest in nitrate content, followed in order by leaves and grain in decreasing amounts. Research with piper sudangrass, sorghum sudangrass and pearl millet has shown the lower 6 inches of the stem contains three times more nitrate than does the top part of the plant. Elevating the cutter bar above this 6-inch point can potentially lower nitrate levels.

Immature or young plants have a greater potential for nitrate accumulation than older plants, so be cautious when allowing livestock on a field that is still immature in growth.

“Adapt cattle to nitrates by allowing hungry cattle to fill prior to releasing them on a field, and always test fields of concern prior to releasing livestock on them,” New said.

Any weather condition which reduces plant growth may increase nitrate accumulation. This includes drought and sometimes cool, cloudy weather.

The same plants that accumulate nitrates also can have prussic acid, perhaps better known to the public-at-large as cyanide. Plants that are stressed due to drought or sprayed with herbicide also can form prussic acid in the leaves and stems.

“Treatment for prussic acid is different than for nitrate toxicity but animals often die too fast for treatment to be effective,” Whitworth said.

Blue-green algae blooms are not an uncommon sight on farm and ranch ponds, especially when weather conditions are hot, dry and the ponds get lower and lower.

“Blue-green algae or cyanobacter produces toxins,” New said. “Some of these toxins are fast acting and can kill an animal shortly after drinking. A producer who finds dead livestock or wildlife near water need to take steps to keep other animals away from the water source and have the carcasses necropsied as soon as possible.”

Dead animals may decompose quickly during hot days, rendering largely useless information. Cyanobacter also can be deadly to humans and pets so suspect water sources should be avoided by one and all. Suspicious water can be tested for microscopic algae and toxins like mycrocystin.

“If in doubt, contact the nearest OSU Cooperative Extension county office for assistance,” New said. “Offices are typically listed under ‘County Government’ in local directories.”

Oklahoma is the nation’s fifth-leading producer of total cattle and calves, and third-leading producer of beef cows, according to data from the USDA National Agricultural Statistics Service.