Parasites

You’ve Got to Be “Ked-ing” Me: All About Sheep Keds

Haley Zynda, OSU Extension Educator ANR, Wayne County

(Image Source: Texas A&M Department of Entomology)

I’ve been hearing so much about ticks lately that it’s really been bugging me. The Asian Longhorned Tick is certainly one to keep an eye out for in our herds and flocks, but another ectoparasite that may affect sheep is the sheep ked, Melophagus ovinus. Keds are a like a tick, but only found on domestic and wild sheep and goats. Typically, keds are most prevalent in the Western United States, but with the ability to ship animals all over the country, it’s important to know what’s really out there.

I already mentioned that keds are similar to ticks, meaning it takes bloodmeals from our stock. Keds only take one bloodmeal per day and it can last from 5-10 minutes. When examining sheep for keds, they actually look like hairy wingless flies, not at all like a tick. They tend to hang out on the neck, breast, flanks, and rump. Rarely are adults found on the belly or the back of sheep because the skin in those areas can become dirtied with mud, dust, or bedding. Profit losses from ked infections may be direct or indirect. Infected fine wool sheep may produce low-quality, scraggly wool. Similar to how other bloodmeal insects can cause skin itching and inflammation, keds are no exception. Sheep may Continue reading →

To Drench, or Not Drench

Dr. Reid Redden, Associate Professor and Extension Sheep and Goat Specialist, Texas A&M AgriLife Extension Service
(Reid’s Ram-blings: July 2021)

This spring was cooler than most and some were fortunate to get a good healthy rain. As things start to warm up, we expect to have problems with internal parasites in sheep and goats. Fortunately, there has been some advancements in technology to help in the fight against these pesky parasites. The bad news is, strategic treatment is not simple, and the more science learns about parasites, the more we realize just how much we don’t understand!

For me, the complexity of life is part fascinating and part frustrating. The intricate process by which sunlight and water grow plants that are eaten by sheep and goats to sustain themselves, grow, and reproduce is truly incredible. It is amazing how they overcome challenges and thrive in the face of adversity. Unfortunately, parasites, predators, and pathogens that negatively impact sheep and goats are just as complex and resilient.

Therein lies the dilemma: how we make Continue reading →

Are Parasites a Limiting Factor in your Operation?

Bill Fosher, Granite State Graziers coordinator and New Hampshire sheep producer
(Previously published in On Pasture: March 1, 2021)

The parasites that infest sheep can be an enormous drag on sheep production. Year in and year out, they probably cause more death and disease in some producers’ lamb crops than any other single factor, including predators.

The days when the answer to parasite management was to drench all the sheep every month are behind us. Parasites have started to evolve resistance to various classes of de-wormers. The problem with chemical resistance is so pronounced in some parts of the Southeast US that there are farms where no de-wormers work anymore, and there’s at least some degree of chemical resistance nearly every place where worms are a problem.

The first step in knowing how to manage parasites in your own farm is to know what’s going on in your flock’s guts and in the environment they inhabit. The second step is to know what environmental factors play into parasite reproduction and infectivity. In the final analysis, the answer for how to Continue reading →

The Role of Fecal Egg Counting in Sheep/Goat Health

Susan Schoenian, Sheep & Goat Specialist, University of Maryland Small Ruminant Extension Program
(Previously published on the American Consortium for Small Ruminant Parasite Control: August 2020)

Although parasite burdens are low in many Ohio systems in the current moment, it is never too early to consider your 2021 parasite management plan. Many producers tend to treat for parasitic infection blindly and routinely, regardless of the true needs of their flocks or herds. For those interested in understanding the importance and implementation of fecal egg counting in your operation when it comes to parasite management be sure to take a peek at this quick read from Susan Schoenian.

A fecal egg count (FEC) is a quantitative measure of how many worm eggs a sheep/goat is passing in each gram of its manure. You get a number like 1000 EPG (eggs per gram of feces).

Fecal egg counts are performed by veterinarians, state diagnostic labs, and independent laboratories. You should only be willing to Continue reading →

Prevent Parasites Through Grazing Management

Melanie Barkley, Livestock Extension Educator, Penn State Extension
(previously published with Penn State Extension: May 31, 2017)

Grazing management and genetic selection can help your flock minimize the impact of parasites.

Parasites continue to plague many sheep and goat producers throughout the grazing season. Internal parasites decrease growth rates and in high levels can even cause death. However, sheep and goat producers can follow several practices to minimize the impacts to their flock or herd. These practices center on grazing management, but can also include genetic selection principles.

Livestock pass internal parasite eggs in their manure. These eggs then hatch and go through several larval stages until they reach an infective stage. This can take as little as six days to go from egg to infective stage. Therefore, producers can use grazing rotations to Continue reading →

An In-Depth Look at Ivermectin

Susan Schoenian, Sheep & Goat Specialist, University of Maryland Small Ruminant Extension Program
(Previously published in Wild and Wooly – Spring 2020)

(Image Source: Valley Vet Supply)

Recently, several media outlets reported the success of an in vitro study conducted in Australia regarding the antiviral effects of ivermectin on the virus that causes COVID-19. An in vitro study is performed outside the living organism, such as in a petri dish; where- as, an in vivo study is conducted in a living organism. A treatment may work in vitro but not in vivo or it may work in both or neither.

Ivermectin has shown in vitro activity against the zika virus, but its effect Continue reading →

Best Management Practices for De-worming Sheep and Goats

With warmer weather projected in the near forecast and pastures beginning to become full and lush, many producers have or will soon be turning their stock out onto pasture. It is critically important that we monitor the health and well-being of our animals on a daily basis. For those that may need treatment due to parasitic infection, it is important to understand which de-worming products to use at the appropriate time and how to correctly incorporate them into your management system.