Green Prairie Animal Hospital · Large Animal Care · Mason County, IL
You’ve got goats going downhill faster than they should. Bottle jaw — that soft, fluid-filled swelling under the chin — showing up in does that looked fine two weeks ago. Kids that aren’t growing the way they should. A ewe that’s thin despite having feed in front of her.
Internal parasites — specifically strongyle worms — are the number one herd health challenge for goat and sheep producers in central Illinois. If you run small ruminants in Mason County, this is the problem that will cost you more than any other if you don’t stay ahead of it. Here’s what you’re dealing with and how to manage it effectively.
What Strongyles Are and Why They Hit Goats So Hard
Strongyles are a family of internal parasites — nematodes, meaning roundworms — that infect the gastrointestinal tract of goats, sheep, and other ruminants. Several species are present in Illinois, but one dominates the clinical picture entirely.
Barber pole worm — Haemonchus contortus — is the most economically significant internal parasite in small ruminants across the United States and the primary strongyle driving production losses in Mason County goat and sheep herds. It lives in the abomasum — the true stomach, the fourth compartment of the ruminant digestive system — where it feeds directly on blood.
A single adult female barber pole worm produces thousands of eggs per day. A heavily infected goat may be carrying thousands of adult worms simultaneously. The blood loss from a significant barber pole worm burden produces anemia — a drop in red blood cell count that reduces the body’s ability to carry oxygen — that can kill a goat within days in severe cases.
The clinical signs follow directly from that blood loss. Pale mucous membranes — visible in the gums and inner eyelids. Bottle jaw — submandibular edema, fluid accumulation under the chin caused by low blood protein from chronic blood loss. Weakness, exercise intolerance, reduced milk production, poor growth in kids. And death, in animals whose burden exceeds their ability to compensate.
Goats are more susceptible to barber pole worm than sheep, and both are far more susceptible than cattle. Drug dosing in goats is also different — goats metabolize anthelmintics faster than sheep and require higher doses to achieve the same effect. A cattle or sheep dose of a dewormer given to a goat is frequently a sub-therapeutic dose that kills some worms and selects for resistance in the survivors.
Anthelmintic Resistance — The Problem That Changes Everything
Ten years ago, treating strongyles in goats was straightforward. Pick a dewormer, rotate products on a schedule, treat the whole herd. That approach is no longer reliable in most goat herds in Illinois — and using it is actively making the situation worse.
Anthelmintic resistance — the ability of worm populations to survive chemical dewormers — has developed in barber pole worm populations across the United States to the point where some herds have worms that are resistant to every available drug class. This didn’t happen randomly. It happened because deworming every animal on a fixed calendar schedule, regardless of whether individual animals needed treatment, exposed the entire worm population to drug pressure and selected for survivors.
The survivors of deworming — the worms that carried resistance genes and survived treatment — reproduced. Their offspring inherited that resistance. Over successive generations and successive treatments, the resistant population grew while the susceptible population shrank. In herds that have been managed this way for years, the worm population is now dominated by resistant individuals that treatment doesn’t reliably kill.
Three drug classes are available for small ruminant internal parasite treatment in the United States — benzimidazoles (white dewormers like fenbendazole), macrocyclic lactones (clear dewormers like ivermectin and doramectin), and imidazothiazoles (yellow dewormers like levamisole). Resistance to all three classes has been documented in Illinois goat herds. Knowing which class still works on your property’s worm population requires testing — not assumption.
FAMACHA Scoring — Targeted Treatment Based on Individual Animal Status
The management approach that replaced calendar-based whole-herd deworming is called targeted selective treatment — treating the animals that actually need it based on individual assessment rather than treating everyone on a schedule.
FAMACHA scoring is the primary tool for implementing targeted selective treatment in goats and sheep. It’s a clinical assessment of the color of the lower eyelid conjunctiva — the pink tissue inside the lower eyelid — compared against a color chart that correlates eyelid color with estimated anemia level.
The FAMACHA chart runs from one to five. Score one is deep red-pink — no anemia, no treatment needed. Score two is red-pink — acceptable, monitor. Score three is pink — borderline, treat based on other factors. Score four is pale pink — anemic, treatment indicated. Score five is white — severely anemic, treat immediately and evaluate whether the animal is worth saving.
FAMACHA is not a perfect diagnostic tool. It assesses anemia caused by blood-sucking parasites — primarily barber pole worm — not total worm burden, and it doesn’t detect all parasite species. But it is a practical, rapid, on-farm tool that identifies the animals most at risk and directs treatment where it produces the most benefit while leaving low-burden animals untreated.
Animals that consistently score high — requiring frequent treatment — are candidates for culling. Resistance to internal parasites has a heritable component. Removing chronically susceptible animals from the breeding population and selecting for animals that maintain acceptable FAMACHA scores without frequent treatment is the long-term genetic approach to herd parasite management.
Fecal Egg Counts — The Diagnostic Foundation
FAMACHA tells you which animals are anemic right now. Fecal egg counts tell you the parasite burden across the herd and — critically — whether the treatment you used actually worked.
A fecal egg count is exactly what it sounds like — a manure sample processed to count the number of parasite eggs per gram. Individual animal fecal egg counts identify the heaviest shedders in the herd — the animals driving most of the pasture contamination — so targeted treatment addresses the animals contributing most to the next generation of infection.
Fecal egg count reduction testing — running a fecal egg count before treatment and again 10 to 14 days after — calculates the percentage reduction in eggs produced by the treatment. A reduction of 95 percent or more indicates the drug class used is still effective on your property’s worm population. A reduction below 90 percent indicates resistance and a need to change protocols.
This test tells you something no other tool can: whether your dewormer is actually working. Without it, you’re treating without knowing whether treatment is effective — which is how resistance develops and how herds end up with worm populations that nothing reliably kills.
Your San Jose veterinarian can walk you through fecal egg count collection, submission, and interpretation, and help you develop a treatment protocol based on what’s actually present on your property rather than what worked somewhere else five years ago.
Refugia — The Management Concept That Preserves Drug Efficacy
Refugia refers to the portion of the worm population that is not exposed to drug treatment — the worms living on pasture as larvae, the worms in animals that weren’t treated, the eggs that haven’t hatched yet. These worms carry susceptible genes. When they reproduce and contribute to the next generation, they dilute the resistant population with susceptible individuals.
Maintaining refugia is the management practice that slows resistance development. Every time you treat the whole herd, you eliminate susceptible worms along with resistant ones and push the population toward resistance. Every time you leave low-burden animals untreated, you preserve susceptible worms in the gene pool.
Practical applications of refugia management include never treating the entire herd simultaneously, leaving animals with acceptable FAMACHA scores untreated, not treating animals immediately before moving to a clean pasture — animals moved to clean pasture immediately after treatment carry only the worms that survived treatment, seeding the new pasture with a resistant population.
These concepts are straightforward once you understand the underlying biology. Your veterinarian can help you apply them to your specific operation — pasture rotation schedule, stocking density, production calendar, and the resistance profile of your current worm population all affect how refugia management gets implemented in practice.
Additional Strongyle Species Worth Knowing
Barber pole worm gets the most attention because it causes the most deaths. But other strongyle species contribute to production losses in Mason County goat and sheep herds and are worth understanding.
Trichostrongylus species — brown stomach worm and bankrupt worm — infect the small intestine and abomasum and cause diarrhea, poor growth, and reduced production without the dramatic anemia of barber pole worm. They are often present alongside Haemonchus in mixed infections.
Teladorsagia — medium stomach worm — is more common in sheep than goats and in cooler climates. It causes diarrhea and production losses and is included in most fecal egg count evaluations.
Nematodirus is a small intestinal parasite that is particularly dangerous in young kids and lambs — it can cause severe diarrhea and death in animals under three months with relatively low egg counts on fecal testing, making it one of the cases where fecal egg counts alone can be misleading in very young animals.
A fecal egg count with larval development and identification — a more detailed analysis that identifies which species are present — gives a complete picture of what your herd is carrying and allows treatment protocols to be targeted accordingly.
Green Prairie Animal Hospital Serves Mason County Small Ruminant Producers
For goat and sheep producers in Mason County and across central Illinois, Green Prairie Animal Hospital’s San Jose location provides full small ruminant veterinary care — FAMACHA training, fecal egg count testing, fecal egg count reduction testing, parasite management consultation, treatment protocol development, and herd health programs built around your operation’s specific resistance profile and production calendar.
Farm calls are standard across Mason County. The San Jose team comes to your operation for herd evaluations, FAMACHA scoring training, and health visits covering multiple animals. As an AAHA-accredited clinic, the diagnostic protocols and treatment recommendations behind every farm call meet the highest standards in veterinary medicine.
Internal parasite management in small ruminants requires a program — not a product. The right program for your herd is built on knowing what you’re dealing with, and that starts with a conversation with your large animal veterinarian.
Call San Jose for Small Ruminant Vet Care in Central Illinois
Green Prairie Animal Hospital’s San Jose location is our large animal center for Mason County and central Illinois. Our team handles goats, sheep, cattle, horses, and hogs — and we do farm calls.
