Ivermectin Dosage for Dogs By Weight

The recommended dose of ivermectin for dogs is 2.72 mcg per pound of body weight, administered orally at monthly intervals.

Ivermectin (Ivomec®, Heartgard®) for dogs dosage chart
Dog’s weight (lbs) Ivermectin dosage (chewable)
Up to 25 lbs 1 chewable of 68 mcg
26 to 50 lbs 1 chewable of 136 mcg
51 to 100 lbs 1 chewable of 272 mcg

Ivermectin for dogs reviews

Ivermectin is a popular veterinary drug used to treat a range of parasitic infections in dogs. Let’s dive into its various aspects:


Ivermectin is effective against various internal and external parasites like heartworm, hookworm, roundworm, and sarcoptic mange. It’s also used to control lice and ticks in dogs.


Ivermectin is highly effective, has a long shelf life, and is relatively cheap compared to other parasite treatments. It’s also well-tolerated by dogs and is available in different forms such as pills, injections, and topical solutions.


Ivermectin can have side effects, especially if not used correctly or if the dog has a sensitivity to the drug. Additionally, some dogs may develop resistance to the drug over time, making it less effective.

Side Effects:

Common side effects of Ivermectin in dogs include vomiting, diarrhea, loss of appetite, and lethargy. In rare cases, it can also cause seizures, tremors, and breathing difficulties.


Ivermectin can be toxic to certain dog breeds, especially those with the MDR1 gene mutation. This gene affects how the body processes the drug, leading to potentially fatal reactions. It’s important to check with your veterinarian before administering Ivermectin to your dog.

Drug Interactions:

Ivermectin can interact with other drugs, such as heartworm preventatives, so it’s important to inform your vet of any medications your dog is taking before starting Ivermectin.


Pregnant and nursing dogs should not receive Ivermectin, as it can be harmful to the developing fetus or puppies. Additionally, dogs with liver or kidney problems may not be able to metabolize the drug effectively.

Research and Studies:

There have been several studies on the safety and efficacy of Ivermectin in dogs, with generally positive results. However, it’s important to remember that results can vary between dogs and to always consult with a veterinarian before starting any new treatment.


If Ivermectin is not appropriate for your dog, there are other treatments available for parasitic infections, such as milbemycin oxime, fipronil, and selamectin. Your vet can help determine the best option for your pet based on their individual needs and health status.

Ivermectin complaints

Like any other drug, it comes with its own set of complaints. Let’s take a look at the most common complaints about Ivermectin for dogs.

Side effects

The most common side effects of Ivermectin for dogs include vomiting, diarrhea, and loss of appetite. In some cases, it can also cause excessive drooling, lethargy, and confusion. These side effects usually go away on their own within a few days, but if they persist, it’s best to consult your veterinarian.


Ivermectin is extremely toxic to dogs, and an overdose can cause serious health problems. Symptoms of an overdose include dilated pupils, tremors, seizures, and even death. It’s essential to follow the recommended dosage for your dog’s weight and to never exceed it.

Allergic reactions

Some dogs may have an allergic reaction to Ivermectin. Symptoms of an allergic reaction include redness, itching, swelling, and hives. If you suspect your dog has an allergic reaction to Ivermectin, it’s crucial to seek veterinary attention immediately.

Ineffective treatment

In some cases, Ivermectin may not be effective in treating the parasite or skin condition it’s meant to. If you notice that your dog’s symptoms are not improving after taking Ivermectin, it’s best to consult your veterinarian for alternative treatment options.

If you notice any unusual side effects or if the medication is not effective, it’s best to consult your veterinarian for further advice. In the end, it’s always better to be safe than sorry!

Is there an alternative to Ivermectin for dogs?

Essential Oils: Essential oils like Neem, Tea Tree, and Lemon Eucalyptus can help repel fleas, ticks, and mites. Just make sure to dilute them properly before applying on your dog’s skin.

Apple Cider Vinegar: A teaspoon or two of apple cider vinegar added to your dog’s food or water can help keep parasites at bay. It’s also good for keeping their skin and coat healthy.

Diatomaceous Earth: This natural substance is made from the fossilized remains of tiny aquatic creatures and works as a mechanical insecticide. You can sprinkle it on your dog’s bedding, or even add it to their food.

Brewer’s Yeast and Garlic: These natural ingredients are great for boosting your dog’s immune system, which helps keep parasites away. They’re also good for their overall health and well-being.

Herbs: Certain herbs like Rosemary, Echinacea, and Nettle can help keep parasites away and support your dog’s immune system. You can add them to their food, or use them in tinctures or teas.

Alternative Description
Milbemycin oxime A type of antiparasitic medication that works by affecting the nervous system of parasites, killing them and preventing further infestations. It’s commonly used to treat heartworm disease, roundworm and hookworm infections.
Selamectin A topical medication that is applied to the skin to treat and prevent parasite infestations, including heartworm disease, fleas, ticks, mites, and some types of worms.
Moxidectin An antiparasitic medication that works by interfering with the parasite’s nervous system, leading to paralysis and death. It’s commonly used to treat heartworm disease, roundworm and hookworm infections, and some types of mites and lice.
Imidacloprid and Moxidectin A combination of two medications that work together to treat and prevent parasite infestations, including heartworm disease, fleas, ticks, and some types of worms.

Keep in mind that these alternative treatments may not be effective for all dogs and may cause side effects in some cases. It’s always best to consult with a veterinarian before starting any new treatment for your furry friend.

FAQs about Ivermectin for dogs

To help you make an informed decision about Ivermectin for your dog, we’ve compiled a list of frequently asked questions and answers below.

What is Ivermectin and how does it work in dogs?

Ivermectin is a broad-spectrum antiparasitic drug that belongs to the class of macrocyclic lactones. It works by binding to certain receptors in the nervous and muscular systems of parasites, causing their paralysis and death. Ivermectin is effective against a wide range of internal and external parasites, including heartworms, ear mites, demodex mites, sarcoptic mange, and certain types of ticks.

Is Ivermectin safe for dogs?

Ivermectin is generally safe for most dogs when used as directed by a veterinarian. However, some dog breeds are more sensitive to Ivermectin than others, especially those with a mutation in the MDR1 gene, which regulates the transport of drugs across the blood-brain barrier. Breeds that are known to be at risk of Ivermectin toxicity include Collies, Shelties, Australian Shepherds, Old English Sheepdogs, and some mixed breeds. Symptoms of Ivermectin toxicity can include lethargy, weakness, tremors, seizures, blindness, and even death in severe cases.

How can I know if my dog is sensitive to Ivermectin?

The best way to know if your dog is sensitive to Ivermectin is to get a genetic test that checks for the MDR1 mutation. This test is simple, non-invasive, and can be done by your veterinarian or a commercial laboratory. If your dog has the mutation, you should avoid giving Ivermectin or any other drugs that can cross the blood-brain barrier, such as certain antibiotics, antiparasitics, and opioids. Instead, you can use alternative drugs or methods that are safe for your dog’s condition.

Can I give my dog Ivermectin without a prescription?

No, you should not give Ivermectin or any other prescription drug to your dog without a veterinarian’s prescription and supervision. This is not only illegal but also dangerous, as you may give the wrong dose or use the drug for the wrong purpose, which can harm your dog or even kill them. Also, some forms of Ivermectin that are meant for use in livestock or horses may be too strong or toxic for dogs, and may cause serious adverse effects.

How do I give Ivermectin to my dog?

Ivermectin comes in various forms and strengths, such as tablets, chewables, topical solutions, and injectables. The dosage and administration of Ivermectin depend on your dog’s weight, age, health status, and the type of parasite being treated or prevented. You should always follow your veterinarian’s instructions and use a calibrated syringe or measuring device to ensure the correct dose. Also, you should avoid giving Ivermectin to pregnant or nursing dogs, puppies under six weeks of age, or dogs with liver or kidney problems, unless specifically advised by your veterinarian.

Can Ivermectin be used on pregnant or lactating dogs?

It is generally not recommended to use Ivermectin on pregnant or lactating dogs. The use of Ivermectin on pregnant or lactating dogs can have harmful effects on both the mother and her puppies.

In pregnant dogs, Ivermectin can cross the placenta and reach the developing fetuses. This can cause birth defects, stillbirths, and even death in some cases. In lactating dogs, Ivermectin can be excreted in the milk and ingested by the puppies, which can cause toxic effects.

If you have a pregnant or lactating dog, it’s best to consult with your veterinarian to determine the safest and most effective treatment options for your pet.

Can Ivermectin be used on puppies?

Ivermectin can be used on puppies, but only in certain doses and under the guidance of a veterinarian. The correct dosage for puppies is based on their weight, and it’s important to make sure you’re giving your puppy the right amount.

Puppies under six weeks of age should not be given Ivermectin. In fact, it’s recommended that puppies not be treated with any parasiticides until they are at least six weeks old, as their immune system is still developing and they are more susceptible to the toxic effects of these drugs.

If you have a puppy that needs to be treated for parasites, it’s best to consult with your veterinarian to determine the safest and most effective treatment options for your pet.

How is Ivermectin administered to dogs?

Ivermectin can be administered to dogs in several ways, including as an injection, an oral tablet, or a topical solution. The method of administration depends on the condition being treated, the dog’s size and weight, and other factors.

Injections are usually given by a veterinarian, and are often used to treat severe cases of parasites, such as heartworm disease. Oral tablets are often given to prevent or treat a variety of internal parasites, and can be administered at home by the pet owner. Topical solutions are applied to the dog’s skin and are used to treat external parasites, such as fleas and ticks.

It’s important to follow the dosage and administration instructions provided by your veterinarian, and to never give your dog more medication than prescribed.

Are there any side effects of Ivermectin in dogs?

While Ivermectin is generally safe for dogs when used in the appropriate doses, there are some potential side effects to be aware of. These can include:

  • Nausea or vomiting
  • Diarrhea
  • Loss of appetite
  • Lethargy or weakness
  • Drooling
  • Tremors or seizures
  • Dilated pupils

In rare cases, Ivermectin toxicity can occur, which can cause more severe symptoms such as blindness, coma, and even death. This is more likely to occur in dogs with certain genetic mutations, such as Collies, Shelties, and Australian Shepherds.

If you notice any of these symptoms in your dog after administering Ivermectin, it’s important to contact your veterinarian immediately.

Can I buy Ivermectin over the counter for my dog?

Ivermectin is a prescription medication, and should only be given to your dog under the guidance of a veterinarian. While some pet stores or online retailers may sell Ivermectin products, it’s important to be cautious and make sure you’re purchasing a safe and effective product.


Hannah Elizabeth is an English animal behavior author, having written for several online publications. With a degree in Animal Behaviour and over a decade of practical animal husbandry experience, Hannah's articles cover everything from pet care to wildlife conservation. When she isn't creating content for blog posts, Hannah enjoys long walks with her Rottweiler cross Senna, reading fantasy novels and breeding aquarium shrimp.

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