Worms in Goats and Sheep: Signs and Control

Quick answer

Worms are the most common health problem in grazing goats and sheep, and the barber pole worm, which sucks blood in the stomach, is the most dangerous. Watch for pale eyelids and gums, bottle jaw, weight loss, weakness, a rough coat and sometimes diarrhoea. Instead of dosing the whole flock on a calendar, treat the animals that need it using eyelid (FAMACHA) checks and dung egg counts, weigh animals so the dose is right, and manage grazing to cut worm numbers. Resistance to dewormers is widespread, so work out a plan with your vet.

The worms that matter

Goats and sheep carry several kinds of roundworm in the stomach and intestines.

• Barber pole worm (Haemonchus contortus) lives in the fourth stomach and feeds on blood. Heavy infections cause severe anaemia and can kill an animal within days, often without diarrhoea. It thrives in warm, wet weather.
• Other stomach and intestinal worms (such as Teladorsagia, Trichostrongylus and Nematodirus) damage the gut, so animals eat less, lose weight and often scour.
• Tapeworms are visible as white segments in the dung and look alarming, but are generally much less harmful than roundworms.
• Liver fluke affects animals grazing wet, marshy land in some regions, and needs specific products.

Coccidia are often confused with worms. They're microscopic parasites that cause diarrhoea in young kids and lambs, and most dewormers don't treat them.

How worms spread

Adult worms lay eggs that pass out in the dung. On the pasture the eggs hatch, and the larvae climb onto the grass, staying mostly in the lowest few centimetres, within about 5 cm (2 in) of the ground. Animals swallow them as they graze, and the cycle repeats. Warm, moist conditions speed this up, so worm burdens rise quickly in the monsoon or wet season.

Around kidding and lambing, does and ewes shed many more eggs than usual (the "periparturient rise"), which contaminates pasture just as young, vulnerable animals start grazing.

Signs of worms

• Pale mucous membranes: the inside of the lower eyelid and the gums look pale pink or white instead of a healthy red-pink
• Bottle jaw: a soft swelling under the jaw from fluid build-up
• Weight loss, poor growth in young stock, or a thin animal with a big belly
• Rough, dull coat or poor wool
• Weakness, lagging behind the flock, lying down a lot, getting tired quickly
• Diarrhoea and dirty back ends (dags), especially with intestinal worms
• Sudden death, particularly with barber pole worm in young or stressed animals

Many of these signs have other causes too, such as poor feeding, coccidiosis, liver fluke or chronic disease, so testing is worth it.

Deciding who to treat

FAMACHA eyelid scoring

FAMACHA is a card that matches the colour of the inner lower eyelid to a score from 1 to 5. A score of 1 is healthy red, and 5 is nearly white, meaning severe anaemia. It's designed for the barber pole worm, since that's the one that causes anaemia.

As a general rule, animals scoring 4 or 5 should be treated with an effective dewormer, and those scoring 1 or 2 usually don't need treatment unless they show other signs. Animals scoring 3 are judged on other signs, and young or weak animals at 3 are often treated because they can deteriorate quickly. Score every few weeks in the worm season, more often in wet, warm weather. Proper FAMACHA training matters, as scoring wrongly can lead to missed cases.

The Five Point Check

Because FAMACHA only picks up blood-sucking worms, the Five Point Check adds four other places to look: the jaw (bottle jaw), the back (body condition), the tail (dags or diarrhoea) and the nose (discharge, which can mean nasal bots or other problems), alongside the eye.

Dung egg counts

A faecal egg count from a vet or lab shows roughly how many worm eggs an animal is passing. Counts from a sample of animals help decide whether a group needs treating. A test after treatment (a faecal egg count reduction test) shows whether your dewormer is still working on your farm.

Treatment: getting it right

Dewormers belong to a few broad drug families, and worms on many farms are resistant to one or more of them. Getting the most out of what still works is the aim.

• Weigh the animal, or use a weigh tape, rather than guessing. Underdosing helps resistance develop.
• Use the right dose for the species. Goats often need a different dose from sheep, and many products aren't licensed for goats. Follow your vet's dosing.
• Give it correctly: oral drenches over the back of the tongue, with the head level.
• Use a product your vet confirms is still effective on your farm, ideally backed by an egg count reduction test.
• Keep records of who was treated, when, with what and the score before treatment.
• Respect meat and milk withdrawal periods: follow the product label and your vet.

Why not treat every animal?

Leaving some healthy animals untreated keeps a population of worms on the pasture that haven't been exposed to the drug (called "refugia"). These dilute the resistant worms that survive treatment. Treating the whole flock regularly, then moving them to clean pasture, selects hard for resistant worms. Targeted treatment slows resistance and saves money.

Prevention and grazing management

• Don't overstock. More animals on the same land means more eggs on the pasture.
• Don't graze too short. Most larvae sit in the bottom few centimetres, so keep forage above roughly 5 cm (2 in) where you can.
• Let goats browse. Shrubs, trees and hedges keep goats eating above the worm zone.
• Rotate pasture and give paddocks rest, cut them for hay, or graze them with cattle or horses, whose worms are mostly different (a few, plus liver fluke, can cross over, especially with cattle).
• Feed well. Well-fed animals cope with worms better, especially in late pregnancy and while feeding young.
• Quarantine new arrivals away from the flock and treat or test them as your vet advises, so you don't buy in resistant worms.
• Keep feed and water off the ground with raised feeders and clean water troughs.
• Breed from resilient animals. Keep and breed from those that rarely need treatment, and cull those that need it again and again.

For general husbandry, see Goat Farming for Beginners and Sheep Farming for Beginners.

When to see a vet

Call a vet promptly if:

• an animal has very pale or white eyelids or gums (FAMACHA 4 or 5)
• you see bottle jaw
• a goat or sheep is weak, can't keep up, or goes down
• there are sudden deaths in the flock
• several animals are scouring, losing weight or failing to grow
• young kids or lambs have diarrhoea, especially with blood or straining
• animals don't improve after deworming, which may mean resistance
• you want a worm control plan, egg counts or a resistance test

In Pakistan

Worm problems peak in the monsoon and the humid months after it, especially on canal-irrigated and low-lying land. Many small farmers deworm the whole herd on a fixed schedule, often with the same product, which encourages resistance. Ask your local veterinary hospital or livestock department about egg counts and which products still work in your area. Before Eid al-Adha, a thin animal with pale eyelids or a swelling under the jaw should raise questions, however attractive the price.

When buying goats or sheep, check eyelids, body condition and back ends, and buy from verified sellers on Paalo.