Get better drenching results with these application tips

ATHENS, Ga. — Internal parasites can chip away at cattle performance and profitability if left unchecked. For beef producers using benzimidazoles — commonly known as white dewormers — getting the application right is just as important as choosing the right product.

Leonor Sicalo Gianechini, who completed her Ph.D. at the University of Georgia, and Nathan Meyer, senior veterinarian at Boehringer Ingelheim, shared their best advice for improving oral drench results chute-side.

Start With Proper Placement For Effective Delivery

“When you’re drenching cattle, it’s important to properly restrain each animal,” Meyer said. “Using a chute or a head catch can help make sure you have good control of the animal’s head while you administer the product.”

For a white dewormer to effectively purge internal parasites, the medication needs to reach the right place in the animal — the rumen. This starts with the correct placement of the applicator:

• The hooked end of the applicator should be inserted at the commissure of the lips, the corner of the mouth.

• Angle the hook toward the back of the mouth in the cheek, so it gets behind the tongue, not on the tongue.

Getting the product behind the tongue is essential, Sicalo Gianechini stressed. If the drench isn’t placed far enough behind the tongue, the esophageal groove reflex may send the drug into the abomasum instead of the rumen, which reduces drench performance.

“You want the medicine to reach the rumen, because with white dewormers, that rumen acts as a reservoir,” Sicalo Gianechini said. “The drug mixes with the particles in the rumen and then is slowly released into the abomasum.

“The abomasum has an acidic pH, causing the drug to be dissolved and properly absorbed in the small intestine. This is why the correct technique of getting white dewormers behind the tongue is an absolute must.”

Get The Product Where It Works Best

White dewormers are usually in and out of an animal’s system within a couple of days. Meyer said oral drenches work well, because the gastrointestinal tract is the largest absorptive surface of the body.

That large surface area means the oral drench has more contact with parasites, which improves its effectiveness.

“If you want good drug efficacy, the main thing is that the worm has to be in contact with the drug for a certain period of time, so the drug can pass through the cuticle (in nematodes) or tegument (in cestodes) and enter the parasites,” Sicalo Gianechini said. “The longer the contact between the active ingredient and the parasite, the better.”

Prevent Waste With Patient Application

Drenching is a task in which slow and steady gets the best results. Impatience, and thus improper placement, can result in regurgitation and wasted product.

“Sometimes, based on how cattle are moving around, patience is our biggest ally,” Meyer said. “You have to take your time and make sure the hook is inserted fully without forcing it.

“You can damage the mouth or esophagus if you force it. It may take some maneuvering to get the V of the hook clear to the commissures of the lips. Then depress the applicator all the way, slowly and steadily.”

Meyer recommends using a low-dose, highly concentrated product, like Synanthic oxfendazole oral suspension, to do the job cost-effectively.

“With some of the large-dose products, you’ll see more waste during application because those animals can’t hold that much product in their mouth,” he said. “It won’t always go down easy, and they’ll tend to spit more of it up.”

Avoid Underdosing With Accurate Animal Weights

Aside from proper application, drenching efficacy also hinges on delivering the right dose.

“Underdosing is a high-risk practice when it comes to the development of drug resistance,” Sicalo Gianechini said.

Meyer explained that underdosing parasites causes them to create a response to the drug instead of being killed. Because a parasite’s life cycle is short, that response gets carried into the genetic material of the next generation, which can lead to resistance.

To avoid underdosing, it’s important to get accurate weights of the cattle receiving the drench. Using a scale to weigh each animal in the chute is ideal, but when that’s not an option, both doctors suggest taking the weight of the heaviest animal in the group and dosing the group according to that animal.

“When you don’t have the exact weight, it’s always better to give them a slightly higher dose versus underdosing,” Sicalo Gianechini said. “You’ll have a big issue if parasites survive.”

Handle And Store Drenches With Care

Correct application and dosing are only part of the equation. How the product is handled and stored also impacts performance.

“White dewormers can settle in the bottle, so make sure to mix the bottle while you work,” Meyer said. “You want to make sure that you’re giving the active ingredient at the correct concentration. I always try to shake the bottle every 20 to 30 head when I’m processing cattle to make sure that it’s a uniform dose given to the animals.”

It’s important to also double-check that the applicator’s dose is set appropriately throughout working the cattle, because the dial can easily get bumped.

Any extra air in the barrel will reduce the correct dose, which is common when switching to a new bottle. Take a quick look at the barrel to ensure air is out of the system and the product takes up the entire space.

Lastly, always read the product label to get instructions on proper storage. Most white dewormers should be kept between 32 and 77 degrees to maintain product efficacy.

If working cattle during a hot day, Meyer suggests using a smaller bottle size or storing it in a cooler.

Before choosing an oral drench, consult with your veterinarian. They’ll be able to help decide how drenches fit into a well-rounded and sustainable deworming program and verify whether an oral drench is best for your operation’s parasite load.