In this complete guide to worming goats using Ivermectin, we answer the most common questions that farmers ask about Ivermectin, including what it is, dosage amounts…and much more!
Table of contents
- What is Ivermectin for Goats?
- How Ivermectin Works (the “Mechanism”)
- Ivermectin is NOT FDA Approved for use with Goats
- Cattle Formulations of Ivermectin cannot be used with Goats
- How to Worm Goats with Ivermectin – What Farmers Need to Know
- Is Ivermectin Safe for Pregnant Goats?
- Ivermectin for Baby Goats
- Withdrawal Time After Ivermectin
- Ivermectin for the Meningeal Worm
- Deworming Goats With Ivermectin – How to Drench a Goat Video
What is Ivermectin for Goats?
Ivermectin is a broad-spectrum anthelminthic (de-wormer) this is used for both internal and parasites. It is one of the drugs that treats roundworms (nematodes) which infect the gastrointestinal tracts and lungs of goats, cattle, sheep, and other animals. It also prevents heartworms in canines and felines. It is used for the treatment of various external parasites in animal species. It is also used in humans to treat river blindness, lice, and scabies.
How Ivermectin Works (the “Mechanism”)
Ivermectin is an anti-parasitic drug, and is a member of the avermectin class of drugs. The drug was discovered by William Campbell and Satoshi Ōmura in 1975, and in 2015, they were awarded the Nobel Prize for their discovery.
Ivermectin does not kill parasites directly. Rather, it interferes with the signals between the nerves and the muscles in the parasite, causing too many chloride ions to flow into cells. As a result, the parasite is first paralyzed and then it dies. The drug act on “glutamate-gated chloride channels.”
In mammals, these channels are only present in the brain and spinal cord. With some few exceptions, and as long as the does is not too high, ivermectin does not cross the blood brain barrier in mammals. As a result, the drug does not normally harm mammals, and only acts on the parasitic invertebrates.
Ivermectin is FDA Approved for Use with Sheep
The dose and withdrawal times for ivermectin are known and clearly spelled out on labels and dosage charts for sheep.
Ivermectin is NOT FDA Approved for use with Goats
Because Ivermectin is not FDA approved for use with goats, worming goats with Ivermectin is an extra label (off label) use.
Per Cornell University: “The FDA regards extra-label use of drugs as an exclusive privilege of the veterinary profession and is only permitted when a bona fide veterinarian-client-patient relationship exists and an appropriate medical diagnosis has been made.”
Because Ivermectin for goats is strictly extra label, a veterinarian must be involved and great care must be taken regarding dosage and withdrawal times, both of which are addressed below in this article.
Cattle Formulations of Ivermectin cannot be used with Goats
It is important to note that no ivermectin formulations for cattle can be used off label with goats. Only the sheep formulations of ivermectin can be used off label with goats.
Goats are not miniature cows. Rather, goats are closely related to sheep. (Cows belong to the family Bovidae; goats and sheep belong to the subfamily Capridae.)
How to Worm Goats with Ivermectin – What Farmers Need to Know
One of the most prevalent and ongoing concerns of the goat farmer is parasitic infestation of the herd because parasites can make a goat ill. One of the most notorious pests is the barber pole worm, which can cause anemia in goats, which can lead to bottle jaw and other complications. Any threat to a goat’s health can be a threat to the finances of goat farm.
Dose Ivermectin Properly to Avoid Drug Resistance
If parasites are exposed to a drug, but they aren’t killed by it, then they develop resistance to it. Once a parasite is resistant to one drug, you will have to switch to a different drug or drug combination to treat your herd. Including ivermectin, there are a limited number of drugs available today to treat parasites. You never want to be in the situation where the parasites in your region have developed resistance to the limited number the drugs. You would have nothing left to use for deworming your goat. As a result, you must dose properly so that you do not help the parasites develop resistance to the drugs.
Misuse of dewormers can cause parasitic drug resistance. Always does properly.
Dosing Ivermectin Properly means Selective Treatment in the Right Amount
Never treat all the animals in the herd at once. This causes drug resistance to develop quickly. Rather, evaluate each goat using the FAMACHA score or the Five Point Check, and then use selective treatment.
Beginning in 2021, guidance is that goats be given combination treatments using multiple drugs. Ivermectin and other drugs should not be mixed together. Rather, the drugs should be administered one right after another at the same time.
To determine which anthelminthic are effective, it is recommended to test with a DrenchRite larval development assay (LDA) or a fecal egg count reduction test. (FECRT, which compares fecal egg counts before and after using dewormer.) Consult with your veterinarian regarding these tests.
Ivermectin Dosage for Goats
Ivermectin, a popular livestock wormer, has been on the market since 1981, and it is FDA approved for sheep but not goats. One of the significant problems with determining the ivermectin dosage in goats is that goat metabolism is different than that of other animals so you can’t use the same dosage as you would for sheep.
Fortunately the recommended dosages are available thanks to the efforts of Ray M. Kaplan, DVM, PhD, DACVM, DEVPC (University of Georgia), who created a Deworming Chart for Goats. This chart was updated with contributions from Patty Scharko DVM, MPH (Clemson University). In 2021 it was updated by Michael Pesato DVM DABVP (Mississippi State University) with assistance from Susan Schoenian of the American Corsortium for Small Ruminant Parasite Control and Dr. Adriano Vatta of Louisiana State. A link to this chart can be found below.
Goat Dewormer Chart updated 2021
Please read the chart completely, especially the notes and footnotes, to understand the proper dosage for your goats. Make sure that your veterinarian is involved in dosage decision making, as Ivermectin usage in goats is off label.
Ivermectin for Goats Orally
With approval of your veterinarian, you can use IVOMEC sheep oral drench on goats.
According to the 2021 update, goats should be given 6 ml of Ivomec sheep drench orally for every 25 lb of weight. This is equivalent to 0.4 mg of ivermectin for every kg of weight. Examples: if the goat weighs 20 lb., then it should get 4.8 ml by mouth of ivermectin Ivomec sheep drench. It is weighs 60 lb., then the dosage is 14.4 ml. In the chart linked to above, the dosages are listed by the weight of the goat, in 5 lb. increments, from a 20 lb. goat through a 250 lb. goat.
Monitor the effectiveness of the anthelminthic by using the FECRT.
Ivermectin Pour-On Dosage for Goats
There is no pour on Ivermectin dosage for goats as this is an unacceptable application method for goats.
Ivermectin Injectable Dose for Goats
Their is no injectable Ivermectin dosage for goats as this is an unacceptable application method for goats.
- Do not use Injectables on Goats.
- DO NOT USE IVOMEC injectable, which is labeled for cattle and swine.
- No injectables are approved for goats.
- Do not give injectables by mouth.
Ivermectin Paste Dosage for Goats
There is no pour on Ivermectin dosage for goats as this is an unacceptable application method for goats.
Is Ivermectin Safe for Pregnant Goats?
Since the use is off label, guidance from the FDA is not available regarding the use of of anthelminthics, including ivermectin, in pregnant goats.
There are goat farmers who use Ivermectin in pregnant goats as their experience with the drug has worked out favorably for them.
However, the decision whether to use ivermectin on pregnant goats should be made upon consultation with your trusted veterinarian. Since you and your veterinarian will already be working closely when administering ivermectin, make sure the vet is made aware of any pregnant goats you may have.
Ivermectin for Baby Goats
Kids are prone to other parasites like adult goats. The goat deworming guidance from Ray M. Kaplan, DVM, however, starts with goats whose weight is at least 20 lb. Additionally, the FDA offers no guidance, since the use of ivermectin if off label.
As a result you should work with your veterinarian to administer ivermectin in your baby goats.
Withdrawal Time After Ivermectin
According to the 2021 guidance, when dosed at 0.4 mg/kg orally, the meat withdrawal time for ivermectin is 20 days, and the milk withdrawal is 20 days. This only applies to Ivomec® Sheep Drench (0.08% or 0.8 mg/ml). You should not give any injectable products made for cattle and pigs orally. If you have done so, however, the withdrawal times listed here do not apply. Milk and Meat withdrawal times may change based on new data from FARAD (Food Animal Residue Avoidance Databank), so consult with your veterinarian for the latest guidance.
Ivermectin for the Meningeal Worm
For meningeal worm (deer worm), do not use ivermectin. Fenbendazole is the better choice. Reference: Cornell University Deer Worm in Small Ruminants Dec 20, 2016
Ivermectin and Other Dewormers
Ivermectin belongs to the group de-wormers known as avermectins. The Avermectins are one type of macrocyclic lactone. Another type of macrolytic lactone in moxidectin (brand name is Cydectin).
If ivermectin is not effective, then you will have to switch to a different drug. Always consult with your veterinarian.
Only two drugs are FDA approved for goats: fenbendazole (brand names are Safe-Guard and Panacur) or albendazole (brand name is Valbazen). Other drugs, including ivermectin are off label.
You may have to use drug combinations, by giving two doses (or even three) to your goats, one right after the other. Only do this with the aid of a veterinarian. You must always keep in mind that you have to prevent the parasites from developing drug resistance.
Monitor the FECRT and LDA, and use FAMACHA and the Five Point check to selectively treat goats in your herd.
