Which Parasites Are Draining Your Goats?

A short list of parasites does most of the damage in goats, and each one calls for a different response. Barber's pole worm drains enough blood to turn a healthy goat anemic within weeks, coccidia hits kids with scours and stunted growth, and the brown stomach worm and black scour worm wear condition off quietly through the cooler months. Tapeworms are the ones you can see, and usually the least harmful. Goats carrying a heavy burden often look completely normal while they seed the pasture and cost you feed conversion, fertility, and milk or meat yield. Which parasite you actually have decides what treatment works, and dosing the whole herd on a calendar is the fastest way to breed worms your dewormer no longer kills.

The first questions we usually hear are whether the rest of the herd is already carrying it, and what the last round of deworming actually did. Rustebakke Veterinary Service is a locally owned practice caring for goats and other livestock around Clarkston, with herd health plans and on-farm visits that let us work your animals here or out in your pasture. Fecal testing paired with a hands-on exam answers both, naming the parasite you are actually facing and the animals that need treatment instead of the whole herd. If an animal is losing condition or your deworming routine is not holding the way it used to, have us out to your place, and call that same day if a goat is pale around the gums and eyelids, weak, or swelling under the jaw, because barber's pole worm moves faster than it looks like it should.

The Five Parasites That Cost You Most

• Barber's pole worm is the fast one, draining enough blood to leave a goat pale, weak, and swollen under the jaw within weeks, especially on irrigated summer pasture.
• The brown stomach worm and black scour worm cause weight loss and dark scours rather than anemia, so an eyelid check alone won't catch them.
• Coccidia belongs to the kid pen, where crowding and damp bedding turn a normal passenger into scours and growth that never fully catches up.
• Dewormer resistance is widespread in goat herds, and treating only the goats that need it, at the right dose, is what keeps your products working.

Why Does Parasite Control Matter When Your Goats Look Healthy?

Internal parasite control in sheep and goats comes down to a short list of gastrointestinal worms that cut feed conversion, growth rate, and milk yield months before a single animal looks sick. A doe carrying a stomach worm burden spends protein repairing gut lining instead of building a fetus or filling an udder, so conception slips and the milk line drops without ever looking like a problem.

Fiber goats grow weaker hair, and market kids take longer to finish on the same ration. None of it reads as disease; it reads as a disappointing weaning weight and a pregnancy check that doesn't match what you bred. A goat in good flesh can still shed thousands of eggs a day onto ground the rest of the herd will graze next month, so the pen that looks fine is often the one reseeding your pasture.

Which Parasites Cause the Most Losses in Goats?

Five intestinal parasites do most of the damage in goats: barber's pole worm, the brown stomach worm, the black scour worm, coccidia, and tapeworms. Where each one lives, what weather favors it, and which part of the gut it attacks decide the response, so naming the parasite comes before you buy any product.

One catch with testing: barber's pole worm, the brown stomach worm, and the black scour worm lay nearly identical eggs, so a routine fecal float lumps them together as "strongyles." When it matters which one is driving the count, a larval culture or a special stain sorts them out. That answer changes the plan, because the eyelid check only tracks barber's pole worm.

Barber's Pole Worm

Each worm bites into the stomach lining and takes a little blood, and a heavy load can take a goat from normal to severely anemic within weeks. Pale gums and pale inner eyelids come first, then weakness and a reluctance to keep up with the group, then the soft fluid swelling under the jaw that producers call bottle jaw. Pulling down the lower eyelid and matching its color to a five-point card, a method called FAMACHA scoring, grades anemia on the spot and tells you which animals in the pen need treatment.

In the Lewis-Clark Valley, barber's pole worm does most of its damage on irrigated pasture and wet bottom ground, where summer heat and steady moisture keep larvae alive well into fall. On dryland range, hot, dry summers kill many larvae before goats ever swallow them. Over winter, the worm can sit dormant inside the goat and restart in spring, which is why a herd that tested clean in December can turn up with high counts after kidding.

A pale, weak goat needs to be seen that day, and handle them quietly, because the stress of being chased and caught can kill a severely anemic animal.

Brown Stomach Worm

The brown stomach worm (*Teladorsagia circumcincta*, still sometimes called *Ostertagia*) is the cool-weather counterpart to barber's pole worm, which makes it more important here than in the warm Southeast, where much of the goat parasite advice gets written. Its larvae handle cold well enough to survive a Northwest winter on pasture, so spring and fall are its peak seasons. The worms burrow into the glands of the abomasum, the true stomach, and the damage there interferes with digestion and appetite. The result is a goat who slowly loses weight and passes loose manure while their eyelids stay pink, which is exactly why FAMACHA scoring alone misses it. Like barber's pole worm, its larvae can go dormant in the stomach wall over winter and emerge in spring, often right around kidding.

Black Scour Worm

Black scour worms (*Trichostrongylus* species) are small, hair-like worms that live mostly in the first stretch of the small intestine, with one species in the abomasum. They thrive in the same cool, damp conditions as the brown stomach worm, and the two often turn up together. Damage to the intestinal lining causes dark, watery scours that stain the hindquarters, along with a poor appetite and a steady loss of condition in weaned kids and yearlings. Adult goats usually build some immunity, though a heavy spring pasture challenge can still show up as dirty tails across the yearling group.

Coccidia in Kids

Coccidiosis is the most common cause of diarrhea in kids between about three weeks and five months old, and the scarring it leaves in the intestinal lining can hold an animal back for life even after the manure firms up. Coccidia live almost everywhere, including in healthy adults who shed small numbers without trouble. What turns a quiet passenger into an outbreak is dose plus stress: a crowded, damp pen, feeders at ground level, weaning, a long haul, or a wet spring. Coccidia aren't worms, so a dewormer does nothing for them. Treatment is a prescription anti-coccidial dosed by weight, usually for the whole kid group, and the sooner it starts the less gut lining is lost. Prevention is mostly housekeeping: dry bedding, pens cleaned out between groups, feed and water raised up where manure can't land in it, and small kidding groups. A kid who goes off feed, strains in the corner, or stays loose for more than a day needs to be seen, because dehydration moves fast at that size.

Tapeworms

Tapeworms (*Moniezia* species) are the parasite producers notice most and usually worry about more than they need to. Goats pick them up by swallowing tiny pasture mites carrying the larval stage, and the white, rice-like segments in the manure are hard to miss. In adult goats they rarely cause harm. A heavy load in young kids during their first grazing season can mean a pot belly, a rough coat, and slow growth, and occasionally a blockage. Seeing segments doesn't mean the whole herd needs a dewormer, and dosing on sight is one of the common ways goats get treated when they didn't need it. Not every stomach worm product kills tapeworms either, so check with us before you treat.

What About Liver Fluke and Lungworms in the Northwest?

Neither one is on the intestinal list, but both turn up on irrigated and wet ground in the inland Northwest. Common liver fluke needs a snail to finish its life cycle, which ties it to seeps, ditch banks, and pond margins, and it shows up as a goat who keeps losing condition on good feed. Giant liver fluke, carried by deer and elk, is a bigger threat to goats than to cattle, because in goats it keeps migrating through the liver instead of settling down. Neither fluke reliably shows up on the routine fecal test. Lungworms cause an on-and-off cough in goats grazing wet, heavily used pasture and need a different lab technique to find, so tell us if you're hearing coughing in the herd.

Do Lice, Mites, and Ticks Matter for Goats?

Yes. External parasites don't live in the gut, but they cost weight, hair, and hide value, and ticks can carry disease. Lice and mites spread fastest in crowded winter housing and usually arrive with a new animal, while ticks peak in spring on brushy and grassy ground across the inland Northwest.

External parasites start as rubbing on fence posts, broken coat along the neck and tailhead, and bare patches of skin, and the weight those animals stop gaining shows up at sale time. The Rocky Mountain wood tick is most active here in spring, and a single tick attached near the head or along the spine can cause tick paralysis, a weakness that starts in the hind legs and usually resolves once the tick is found and removed. A quarantine pen for incoming stock, a hands-on look at the skin while they're caught, and treating the whole affected group rather than the worst individual keep a small problem small. A skin scraping read under the microscope tells mange mites apart from lice and from a non-parasitic skin problem, and we can take that sample on an on-farm or haul-in large animal visit.

Why Are Dewormers Failing on So Many Goat Farms?

Dewormer resistance is widespread in US goat herds, and many farms now carry worms that survive more than one drug class. Every treatment kills the susceptible worms and leaves the resistant ones to breed, so whole-herd dosing, underdosing, and frequent treatment all speed it up. No new dewormer classes are on the way, so protecting the ones that still work matters.

Only three classes of dewormer are available for goats in the US, and only a few products carry a goat label. Most of what gets used on goats is extra-label, which means it needs a veterinarian's dose and a milk and meat withdrawal time set for goats rather than borrowed from the cattle or sheep label.

What Speeds Up Resistance on a Goat Farm?

• Treating the whole herd: Every goat dosed that didn't need it adds selection pressure, which is the core problem with calendar deworming.
• Guessing weight: Underdosing leaves the toughest worms alive. Goats also clear dewormers faster than sheep or cattle and usually need a higher dose than those labels list.
• Using pour-ons: Pour-on products absorb poorly through goat skin, so the dose that reaches the worms is often too low to kill them.
• Deworming, then moving to clean pasture: The only worms left to seed the new paddock are the ones that survived the drug.
• Bringing home someone else's worms: A new goat can arrive carrying worms resistant to every product you own.
• Treating too often: The more often a herd is dosed, the faster resistant worms take over.

How Do You Slow Resistance Down?

The heart of sustainable parasite control is treating fewer goats, not more. The worms that survive a dose pass their genes along, so when a whole pen gets dosed the same morning, the survivors breeding the next generation are the resistant ones. Leaving sound, well-conditioned goats untreated keeps a population of ordinary drug-susceptible worms, called refugia, on the farm to dilute the resistant ones.

When a goat does need treatment, current guidance favors giving two or three drug classes together, each at a full goat dose, rather than switching products with every treatment. We'll set that combination and its withdrawal times with you. New arrivals should be treated with a combination on arrival, held in a dry lot away from pasture, and rechecked with a fecal egg count before they join the herd. Goats who need treatment over and over are worth culling from the breeding program, since resilience to worms is partly inherited. Copper oxide wire particles can help against barber's pole worm in some herds, and a feed-through supplement containing a worm-trapping fungus reduces larvae in manure, though neither replaces testing and targeted treatment.

How Can You Tell If a Dewormer Has Stopped Working?

Running fecal egg counts before treatment and again ten to fourteen days afterward is how you find out whether a dewormer still works on your place, and skipping that second count is one of the most common pitfalls in small ruminant parasite management. A count that barely drops means the product, the dose, or the whole approach needs rechecking before the next round.

We run those egg counts in our in-house lab or send them out for more specialized testing when needed, and the before-and-after numbers tell us what to change. A thin animal with pale eyelids gets bloodwork alongside the fecal sample, because how much blood they have lost decides how urgent the case is. A herd review once or twice a year, with your records of what you treated and when, catches a failing product before it costs you a season. Our veterinarians who make farm calls can tell you what's holding and what's slipping on places around Clarkston.

How Do You Decide Which Goats to Treat?

Treatment goes to the goats showing signs, meaning poor eyelid color, falling condition, scours, or high egg counts, plus the groups least able to cope, like late-pregnant does and growing kids. Because the eyelid check only tracks barber's pole worm, pair it with a look at body condition, the tail for scour staining, and the jaw for swelling.

A full coat hides a startling amount of weight loss, so body-condition scoring is done with your hands on the spine, ribs, and sternum instead of from across the pen. Guessing weight by eye usually means underdosing, so weigh the animals you can and check the dose with us before you draw anything up. A product that failed last season should be replaced rather than repeated.

Does Moving Goats to New Pasture Cut Worm Loads?

It can, when the timing is right. Most infective larvae sit in the bottom two inches of pasture, so grazing management that moves goats out before they graze that close to the soil cuts how many larvae they swallow. Rest periods, stocking density, and grazing cattle behind goats all reduce the worm load on the ground.

A paddock grazed hard needs rest before it comes back into rotation, and how long depends on weather more than the calendar. In the Lewis-Clark Valley, hot, dry summers kill larvae quickly on dryland ground, while irrigated pasture and spring rain keep them alive much longer. Spring also brings what's called the periparturient rise: a doe's immunity dips around kidding, her egg count climbs, and she seeds the pasture right as her kids start grazing. More goats on less ground means more eggs per acre, and the worms that bother small ruminants mostly don't establish in cattle, so running cattle through a paddock after your goats removes larvae without recycling them. Put kids and yearlings on the cleanest ground you have, ahead of the adults, since they have the least immunity to spare. Hay aftermath and newly seeded ground tend to be the lowest-risk pasture on most places.

What Goat Producers Ask Us About Deworming and Bottle Jaw

How often should I deworm my goats?

There isn't one number that fits every herd, and that's the whole point of testing. Season, stocking density, age group, and what your egg counts say all move the answer, so animals on irrigated pasture in July need something different than the same animals on dry range in October. Test, treat the ones that need it, then check whether the treatment held.

Should I rotate dewormers every time I treat?

No. Switching classes with every treatment used to be standard advice, but it tends to build resistance to all of them at once. Current guidance is to treat only the goats that need it, use a combination of classes when we recommend one, and confirm the result with a follow-up egg count.

Is bottle jaw always barber's pole worm?

Bottle jaw means blood protein has dropped far enough to let fluid leak into the tissue, and barber's pole worm is the most common reason for it in goats, though not the only one. Liver fluke does the same thing more slowly, and so can a serious protein shortage in the ration, other heavy worm burdens, or Johne's disease. An eyelid check and a fecal sample sort most cases out quickly, so call us about that swelling either way.

Can my family catch parasites from our goats?

The stomach worms and coccidia that cost you the most production are livestock parasites and don't infect people. Other causes of scours in young kids, including *Cryptosporidium* and *Giardia*, can pass to people, so gloves and real handwashing matter while you're treating a sick kid, especially around small children or anyone pregnant or immune-suppressed. Sarcoptic mange mites off a goat can also leave an itchy rash on the arms of whoever is handling them, though it clears once the animal is treated. Ticks pulled off a goat can carry disease to the handler too, so use a tool rather than bare fingers.

Building a Parasite Plan for Your Place

A good plan takes a few decisions made on real information instead of a calendar, and it's the best way to keep the dewormers you have working for years to come. Rustebakke Veterinary Service sees goats here in Clarkston and out on the place, so get in touch to build a plan that fits the herd you have, and we'll go over your ground, your groups, and your treatment records and tell you what we'd change first.