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Goats infected with gastrointestinal parasites shed parasite eggs in their manure. Under warm, moist conditions, those eggs can develop into larvae. Eventually they reach the infective stage and move onto vegetation, where goats can ingest them while grazing.

Barber pole worm (Haemonchus contortus) is one of the biggest parasite concerns for goats. This blood-sucking parasite causes blood loss, which can lead to anemia and, in severe cases, death (O’Brien 2017).

Under hot summer conditions, barber pole worm larvae can develop to the infective (L3) stage in as little as three to four days (Zajac 2013).

This is one reason I don’t keep our goats and sheep in the same grazing area for more than three days. Moving before larvae reach the infective stage can help reduce the opportunity for animals to ingest larvae that developed from eggs deposited during that grazing period.

Infective larvae need moisture to move onto vegetation. This is one reason parasite exposure can be greater when goats are grazing damp forage or grazing closer to the ground. Research on parasite management also emphasizes the relationship between pasture conditions, grazing management and parasite exposure (Andries 2013; Poudel 2024).

A paddock may have been out of the rotation for the same timeframe earlier in the season, but that doesn’t mean the forage has actually recovered enough to graze again. If goats return before the forage has adequately recovered, they may graze too close to the ground.

Residual height is an important baseline here (what is left after you move your goats to a new paddock). Infective parasite larvae are concentrated in the lower 3 to 4 inches of forage, which is why leaving a residual of about 4 to 5 inches can help reduce the likelihood that grazing animals will ingest infective larvae (Hart 2024). Penn State Extension similarly recommends maintaining at least 4 inches of growth in areas grazed by small ruminants to decrease the likelihood of ingesting parasite larvae (Barkley 2026).

If you continue following the same set “schedule” from spring grazing while forage recovery slows, eventually you’ll start grazing pasture that isn’t actually ready for grazing from a growth standpoint.

Grazing too low can also slow pasture recovery. When too much leaf material is removed, plants have less capacity for photosynthesis and regrowth.

Instead of using a set number of days to determine when goats return, I prefer a flexible grazing system that responds to current conditions. Rainfall, temperature and forage growth all affect how quickly a paddock is ready to be grazed again.

That may require slowing the overall rotation, incorporating additional acreage or forage resources, or otherwise adjusting the grazing plan rather than returning to a paddock before it is ready.

During our regular goat herd health checks, we evaluate body condition, FAMACHA score and overall appearance. I continue watching those same indicators throughout the grazing season during daily herd and forage checks.

With barber pole worm in particular, don’t rely on diarrhea as the primary sign that something is wrong. Because barber pole worms feed on blood, anemia is one of the biggest concerns. Clinical signs of parasite infection can include weakness, weight or condition loss, loss of appetite, anemia and sub-mandibular edema, commonly called bottle jaw (O’Brien 2017).

Instead of automatically treating an entire herd on a set schedule, the goal is to identify which animals actually need treatment. FAMACHA scoring, body condition, clinical signs, fecal egg counts and treatment history can all provide information to help make those decisions.

It is also useful to keep track of which animals repeatedly require treatment. Parasite susceptibility isn’t necessarily equal across a herd, and an animal that continually struggles with parasites may need to be managed differently or considered when making future breeding and culling decisions.

Selective treatment also helps maintain refugia, or a population of parasites that has had less exposure to dewormers. These untreated parasite populations tend to have lower levels of drug-resistance genes than parasites that survive treatment. As the populations mix, they can help dilute resistance genes and maintain the effectiveness of available dewormers (Ehrhardt 2016).

Your veterinarian can also help you develop a parasite-management and deworming protocol appropriate for your herd and determine whether the dewormers you’re using are still effective.

If we’re seeing parasite problems, treatment is only one part of the response. It’s important to evaluate the grazing system and determine whether something needs to change.

That might mean providing goats with more forage or paddocks, using available browse or wooded areas, supplementing forage, or giving previously grazed paddocks more time before animals return.

Thirty days is a starting point, not an indication that parasite risk is gone. Research from Zajac provides some important context for just how long infective larvae can remain on pasture. In temperate regions of the U.S., pasture may need to rest for about three months during hot weather to remove most larvae. During cool weather, that period may extend to six months (Zajac 2013).

Meningeal worm (Parelaphostrongylus tenuis) behaves very differently. White-tailed deer are the normal host, while small ruminants are considered dead end hosts. Its life cycle also involves snails and slugs, which goats and other small ruminants can accidentally ingest while grazing (Stanton 2022).

Unlike barber pole worm, meningeal worm can migrate into the central nervous system of a goat or sheep and cause neurological damage. Signs can include an abnormal gait, stumbling, hind-end weakness and, in severe cases, paralysis.

This is one parasite where catching the signs early is particularly important. Research from the American Consortium for Small Ruminant Parasite Control found that better outcomes were likely related to closer observation and earlier identification of meningeal worm damage (Stanton 2022).

We’ve dealt with meningeal worm on our own farm, so this is something I’m particularly aware of as the grazing season progresses. If I see neurological changes, weakness or an abnormal gait, meningeal worm is one of the possibilities I may need to address.

I cover symptoms, diagnosis, treatment and prevention in more detail in my article Meningeal worm in goats and small ruminants.

Rather than sticking with the same grazing schedule, pay attention to what your pasture and your goats are telling you. Adjusting your rotation as conditions change can help you stay ahead of parasite problems rather than trying to catch up with them.

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