Treating Goat Lice With Ivermectin: Administration Guide

Goats commonly suffer from lice infestations that require treatment to prevent discomfort, skin irritation, reduced weight gain, and anemia in severe cases. Ivermectin is an effective oral treatment that can eliminate lice from goats and provide long-lasting protection against re-infestation.

Ivermectin belongs to the macrocyclic lactone class of endectocides with antiparasitic properties. It binds selectively and with high affinity to glutamate-gated chloride ion channels present in invertebrate nerve and muscle cells, causing paralysis and death of the parasites.

Ivermectin does not readily cross the blood-brain barrier in goats, allowing it to be a safe, systemic treatment for lice. When given orally at an appropriate dosage, ivermectin is absorbed rapidly, transported via the bloodstream, and provides broad-spectrum activity against parasitic arthropods, including lice.

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Symptoms of Lice in Goats

Goats infected with lice often exhibit intense itching and will constantly rub or scratch themselves against objects to relieve the irritation. This leads to patchy hair loss as the goat damages its coat through persistent scratching.

Blood-sucking lice can also cause anemia in heavy infestations. The lice feed on the blood of the goat, leading to a loss of red blood cells and a reduction in the oxygen-carrying capacity of the goat’s blood. Anemia causes lethargy, weakness, and reduced productivity.

The constant irritation from lice infestations causes goats to be distracted from grazing and feeding. This can lead to weight loss and poor body condition. Lice-infested goats often appear unthrifty and underweight.

Severe lice infections that are left untreated can lead to a decline in health, reduced growth rates, and even death of the animal. So it is important to identify and treat lice infestations promptly in goats.

Life Cycle of Lice

Lice have a fairly straightforward life cycle that allows them to multiply quickly. It begins when the adult female louse lays eggs, known as nits, by cementing them onto hair shafts close to the skin. Nits hatch within 1 – 2 weeks, releasing immature lice called nymphs.

Nymphs will immediately begin feeding on the goat’s blood and reach maturity within 2 – 3 weeks. At maturity, lice can multiply rapidly, with females laying up to 10 nits per day. Their entire life cycle from egg to adult takes 3-4 weeks. This allows louse populations to grow exponentially in a short period.

Lice can spread rapidly from goat to goat through direct contact. New infestations often occur when new goats are introduced into the herd without quarantine and treatment. This permits lice to be passed from carrier animals to the existing herd.

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Using Ivermectin for Lice Treatment in Goats

Ivermectin is an anti-parasitic medication that is effective at killing lice, mites, and other parasites in goats. It works by paralyzing the nervous system of lice, causing them to die within a short time. Ivermectin can be administered to goats in three ways:

– Orally: This is the most common method. Ivermectin paste or liquid is given to the goat by mouth. This allows the ivermectin to be absorbed into the bloodstream through the digestive tract.

– Injection: Ivermectin can also be injected under the skin (subcutaneously). This allows the medication to be rapidly absorbed into the bloodstream.

– Topical: The ivermectin pour-on formulations can be applied directly onto the goat’s skin. This causes the ivermectin to be absorbed through the skin and into the bloodstream.

One of the advantages of ivermectin is its long-lasting effect. After being given a single dose of ivermectin, the drug remains active in the goat’s body for 30 – 45 days. This long duration of activity means goat owners don’t have to treat their herds as frequently for lice. One dose eliminates lice infestations and protects against reinfestation for about a month.

Ivermectin Dosage for Goats

Ivermectin is given to goats orally, by injection, or poured along the back. The dose is based on the animal’s body weight.

For oral administration, the recommended dose is 0.2 mg/kg body weight. For example, if a goat weighs 50 lbs, the dose would be 0.2 mg/kg x 22.7 kg = 4.54 mg (which rounds up to 5 mg). The dosage may also be calculated at 1 ml per 22 lbs body weight. Using the example above of a 50 lb goat, the dose would be 50/22 = 2.27 ml, rounded up to 2.5 ml.

Ivermectin is given orally, subcutaneously, or poured on the back of the animal. If given orally, the dose should be repeated in 10 – 14 days. When injected or poured along the back, a single dose is usually sufficient. However, a second dose may be given 10-14 days later if lice are still present.

The efficacy of a single dose of ivermectin is around 90 – 100 percent. Repeat doses ensure any remaining lice are killed before they can multiply. Following the label directions closely is important for proper dosing. An underdose may not fully eliminate the lice infestation.

Ivermectin Treatment Schedule

When using ivermectin to treat lice in goats, it’s important to treat the entire herd at the same time. This helps ensure all animals are cleared of lice concurrently. 

Ivermectin kills the adult lice, but not the eggs. Therefore, it’s essential to administer a second dose 10 – 14 days after the initial dose to kill newly hatched lice before they can mature and lay more eggs.

For the best results, some goat owners combine ivermectin treatment with a topical pyrethrins spray. The ivermectin kills the lice internally, while the pyrethrins kill any eggs and lice on the skin and coat. This two-pronged approach helps break the lice life cycle and clear infestations quickly.

Treating the whole herd twice, 10 – 14 days apart, is the recommended schedule when using ivermectin to eliminate lice in goats completely. Monitoring the goats closely afterward and continuing prevention methods will help prevent future infestations.

Other Lice Treatment Options

While ivermectin is considered the most effective treatment for lice in goats, some other options can be used as well:

1) Pyrethrin sprays

Pyrethrin is a botanical insecticide that can kill lice on contact. Sprays containing pyrethrin can be applied to the goat’s body to kill adult lice. Some sprays also contain piperonyl butoxide (PBO) which helps extend the effectiveness.

Be sure to fully saturate the goat’s hair coat when applying. Re-treatment may be needed after 7-10 days to kill newly hatched nymphs. Exercise caution to avoid getting sprays in the goat’s eyes.

2) Diatomaceous earth

This natural product composed of tiny fossilized algae can help control lice through mechanical action. The sharp edges of the particles can abrade the waxy outer coating of the lice, causing them to dehydrate.

Apply a dusting over the goat’s coat, especially concentrating on the areas around the tail, flanks, and neck where lice congregate. Reapply every 2-3 weeks as needed. Food grade diatomaceous earth is the safest to use.

3) Manual removal of lice/nits

For mild infestations, lice and nits can be removed manually by combing through the goat’s hair coat and removing any lice and nits that are observed. Use a fine-toothed lice comb and pass it over the entire body, paying close attention to the areas where lice tend to gather.

Drop any collected lice into a container of soapy water or alcohol to kill them. Repeat combing daily until the lice are gone. This labor-intensive method works best for small herds.

Using multiple approaches helps break the lice life cycle and prevent reinfestation, these options provide additional means of controlling lice in goats when used in conjunction with ivermectin treatment. They help eliminate any lice that may have survived the initial ivermectin application.

Prevention of Lice on Goats

Keeping lice under control starts with prevention. Here are some tips:

– Quarantine new goats: Isolate any new goats for at least 2 weeks before introducing them to your existing herd. Check them thoroughly for signs of lice during quarantine.

– Regular herd health checks: Closely inspect each goat at least once a week. Look for lice eggs (nits) as well as live lice, especially during spring and summer. Catching an infestation early makes treatment easier.

– Avoid overcrowding: Overcrowded conditions allow lice to spread rapidly from goat to goat. Make sure your goats have enough space and are not packed in too tightly.

– Reduce stress: Stress from poor nutrition, illness, or other factors can make goats more susceptible to lice. Keep your goats healthy and minimize stressors.

– Clean bedding: Change out bedding frequently to prevent a lice infestation from accumulating. Clean barns, sheds, milking stands, and other areas.

– Coordinate treatment: To avoid reinfestation, coordinate lice treatment with other goat owners in your area. Treating your herd alone may not be sufficient.

Regular inspection, quarantine, sanitation, and coordination with other owners are key to preventing lice from taking hold in your herd. With proactive management, you can keep your goat’s lice-free and healthy.

Related:  Pain Killer For Goats: Examples, Dosage & Side Effects


Controlling lice is crucial for maintaining the health and productivity of a goat herd. Ivermectin has proven to be an effective treatment, providing long-lasting protection when administered correctly. I hope you find this guide resourceful on using Ivermectin to treat lice on goats.

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