Parasites

Sheep, Goats, and Worms – Oh My!

Dr. Emily Nogay, DVM, Faculty, OSU Large Animal Services
(Previously published online with Ohio’s Country Journal and Ohio Ag Net: August, 10, 2025)

Skinny goat? Worms. Diarrhea? Worms. Pale eyelids? Worms. Gastrointestinal parasites often take the blame for any small ruminant that is looking ill. Many times, they are responsible; however, it is important to remember that parasites are a natural part of life, especially for animals that eat off the ground.

Although sheep and goats are susceptible to many types of gastrointestinal parasites, there is one that takes the cake – the barber pole worm or Haemonchus contortus. This worm lives inside the true stomach (abomasum) and attaches to the stomach lining to feed on the blood of the animal. This worm is common in all sheep and goats, and unfortunately, it is nearly impossible to eliminate. Large enough worm burdens can cause weight loss, diarrhea, anemia, localized edema (also known as “bottle jaw”), and subsequent death. Animals become Continue reading Sheep, Goats, and Worms – Oh My! →

Guide for Control of External Parasites of Sheep and Goats

Marcy Ward, Extension Livestock Specialist, New Mexico State University
(Previously published with New Mexico State University: Guide B-112:Guide for Control of External Parasites of Sheep and Goats)

(Image Source: AWI – Australian Wool Innovation Limited)

External parasites can greatly impact wool quality in sheep, milk production in sheep and goats, and overall animal health. Therefore it is very important to include a parasite control program in a herd health management plan. Increased regulations have removed many traditional pest control products from the market. With technological advancements, however, effective systemic parasite control is still possible.

With the use of any drug or chemical, following label instruction is imperative for getting the proper results while reducing the risk of
product resistance.

Fleeceworms (Wool Maggots)
Even in well-managed flocks, Continue reading Guide for Control of External Parasites of Sheep and Goats →

Sustainable Parasite Control for Sheep and Goats

Dr. Leyla Rios de Alvarez, Assistant Professor, Mississippi State University Extension
(Previously published online with Mississippi State University Extension: POD-02-25)

(Image Source: University of Calgary)

One of the main drawbacks in small ruminant production systems worldwide is gastrointestinal nematodes (GIN), or worms. The lack of options for controlling worms is mainly a result of increasing resistance these parasites have developed in the last decades. This has caused economic losses to farmers with grazing production systems.

Since 2001, GIN infection was the most prevalent disease, reported by 74 percent of the U.S. farmers surveyed in a National Animal Health Monitoring System study. According to the 2021 Census of Agriculture, U.S. producers have 5,170,000 sheep and 2,582,000 goats. In the last decades, these numbers have decreased annually. Studies are needed to determine if parasite resistance to commercial de-wormers is a factor in this decrease.

Gastrointestinal Worm Life Cycle

Most GINs that affect sheep and goats have a direct life cycle, meaning they Continue reading…

Thinking Outside the Box – The Use of Plant Compounds as Natural Anthelmintics

Dr. Brady Campbell, Assistant Professor, State Small Ruminant Extension Specialist

(Image Source: Hoste et al., 2012)

By now, most producers should be aware that as of June 11th, all over-the-counter antibiotics will require a veterinarian prescription. Although anthelmintic or de-worming products are not classified as an antibiotic and will still be available for purchase at your local retailor, I can’t help but think about the relationship between these two categories of livestock products. Many animal health products available on the marketplace today are easily accessible and easy to use. However, because of this ease and without the detailed knowledge of a veterinarian, unfortunately, these products have been over and/or improperly used, thus leading to resistance. Resistance towards whatever we may be treating for is one of the main drivers for removal from retail shelves and being placed back into the hands of our veterinarians. Thinking a bit further as we begin our fast approach into peak grazing and parasite seasons, I can’t help but wonder what will happen to our currently supply of anthelmintics in the near future. Now hear me out, I’m not suggesting that these products also be removed from producers easy reach, but what I am pointing out is the need for judicious/calculated/careful or targeted used of these products.

With this being said, there are several management practices that can be Continue reading Thinking Outside the Box – The Use of Plant Compounds as Natural Anthelmintics →