Drought Sets Cattle, Pastures Up For Parasite Problems

Control parasites this spring to head off pasture buildup

Drought may have set the stage for a critical parasite year in the South with the potential for big losses.

“With the rain returning this past fall and winter, we really saw the parasites come out,” says Dr. Tom Craig, parasitologist and professor, Texas A&M University. “We actually saw cases of Ostertagiasis, which is fairly uncommon.”

He says it didn’t take many parasites before things got bad for the cattle that were surviving on poor-quality forage for about two years. The animals were easy targets due to poor body condition and weakened immune systems. But, he says, those cattle may be in for another tough year if parasites aren’t reined in.

“With more grazing available and more moisture to enable parasite movement,1 cattle will likely pick up significantly larger parasite loads than they did during dry years,” Dr. Craig says.

Clinical disease, like the Ostertagiasis Dr. Craig saw last fall, is caused as Ostertagia larvae leave their arrested, or hibernation, state in the stomach lining and develop into egg-producing adults.2

“If producers can clear these larvae from cattle in the late spring before they emerge as adults, it will help prevent damage to the host animal and help decrease future pasture contamination,” Dr. Craig says.

Fortunately, Dr. Frank Hurtig, director, Merial Veterinary Services, says producers have an opportunity to interrupt this cycle with a spring treatment of an IVOMEC® (ivermectin) Brand Product — helping prevent further losses and reducing pasture contamination.

“Spring parasite treatments are really about pasture health, not animal health,” Dr. Craig says. “We want to keep pasture contamination below the threshold that will cause economic disease.”

In the South, cattle graze all winter long, which means they’re almost continually exposed to parasites, Dr. Craig says.

“In Texas, timing parasite treatments for late April or early May kills the parasites in cattle before they can do real damage to the stomach of the cow,” Dr. Craig says. “It also helps eliminate the parasites before they become egg-laying adults and recontaminate pastures.”

Dr. Hurtig says producers need to work with their veterinarian when choosing a parasite control product — helping ensure they get the best results for their parasite control investment.

“Drench-type or white dewormers are only effective against a limited spectrum of parasites on the day of treatment,”3 he explains. “However, IVOMEC Brand Products are effective for 14 to 28 days, depending on the parasite and product used.3 They control parasites in the animal at the time of treatment, including inhibited Ostertagia larvae, and those picked up from late-spring pastures, giving producers a wider window for more effective parasite control.”

In this potentially high-risk year, Dr. Hurtig encourages cattle producers to not roll the dice on parasite control or parasite control products. Unlike generic products, IVOMEC Brand Products are backed by a 100% Product Satisfaction Guarantee.

“The drought may be over, but cattle may still be hampered by residual effects on production and fertility,” Dr. Hurtig says. “Carrying a load of internal parasites that decrease digestion and nutritional absorption will only make a return to good condition a more difficult and drawn-out process. Producers should consult with their veterinarian on how spring parasite control with an IVOMEC Brand Product can help get their herd and pastures on the road to recovery.”