Ivermectin for Guinea Pigs - Dosage, Uses and Side Effects

Laura García Ortiz
By Laura García Ortiz, Veterinarian specialized in feline medicine. May 31, 2022
Ivermectin for Guinea Pigs - Dosage, Uses and Side Effects

Ivermectin is a macrocyclic lactone used to treat external parasites in many mammals. Ivermectin is especially useful for eliminating small parasites in guinea pigs, such as fleas, lice, and mites. As every guinea pig owner knows, skin diseases are one of the most common health problems in guinea pigs. This medication is not only effective but also quite safe to use on small mammals, and there are few known side effects in guinea pigs.

Continue reading this AnimalWised article to learn more about the use of ivermectin in guinea pigs, its dosage and side effects.


  1. What is ivermectin?
  2. What is ivermectin used for in guinea pigs?
  3. Ivermectin dosage for guinea pigs
  4. Contraindications of ivermectin in guinea pigs
  5. Side effects of ivermectin in guinea pigs

What is ivermectin?

Ivermectin is an endocide, i.e., a drug used to treat and prevent external and internal parasitism in various animal species, including guinea pigs.

This active ingredient belongs to the group of macrocyclic lactones with a unique mechanism of action. Ivermectin binds selectively and with high affinity to glutamate-activated chloride ion channels in invertebrate nerve and muscle cells. This union produces an increase in the permeability of the cell membrane for chloride ions, which leads to a hyperpolarization of nerve or muscle cells that produces paralysis and death of the parasite.

Ivermectin was discovered in 1970. Since then, its use has been widespread. Because of its effectiveness in humans and animals, ivermectin is on the World Health Organization's list of essential medicines. The scientists who discovered it, Satoshi Ōmura of Kitasato University and William Campbell of Merck, were awarded the Nobel Prize in Physiology or Medicine in 2015.

This drug is currently available in the UK and US by prescription only.

If you suspect that your guinea pig may be infested with mites, then read on in this other article, where we explain the most common symptoms of mites in guinea pigs as well as the various treatment options.

What is ivermectin used for in guinea pigs?

Since internal parasites are extremely rare in guinea pigs, ivermectin is mostly used to treat external parasites such as mites, maggots, and lice. However, this treatment has not been shown to be effective against tapeworms, ticks, or fleas. The most common parasites are mites, namely the following:

  • Trixacarus scabei: causes severe symptoms such as itching, hair loss, self-injury that can lead to secondary infections, skin redness, scaling, weakness and behavioral changes. Chronic parasitosis leads to thickening of the outer layer of the skin (hyperkeratosis) and even to seizures in more serious cases.

  • Chirodiscoides caviae: is the most common fur mite affecting guinea pigs. In healthy guinea pigs, the infestation is generally asymptomatic.

  • Psoroptes cuniculi: Produces large crusts in the ear canal and, if not treated, it can completely block it.

  • Cheyletiella parasitivorax: also known as "walking scales", produces large scales, especially on the back of the guinea pig.

Other mites that may affect these animals to a lesser degree are the ear mange mite (Notoedres muris) and Itch mite (Sarcoptes scabei).

These parasites can also be treated with selamectin in addition to ivermectin.

If you suspect that your guinea pig may be infested with lice, do not miss this other article where we discuss the symptoms, treatment, and prevention of lice in guinea pigs.

Ivermectin dosage for guinea pigs

Due to its wide range of applications, ivermectin for guinea pigs is available in several forms: topical, injectable, and oral solutions. The dosage of ivermectin for guinea pigs depends on the parasite being treated. In general, the ivermectin dose is as follows:

  • For treatment of Trixacarus scabeie mite: 0.2 ml ivermectin subcutaneously in adult guinea pigs and 0.1 ml in young guinea pigs.

  • For treatment of Chirodiscoides caviae mite: topical ivermectin (at a dose of 0.5 mg/kg).

  • For the treatment of Psoroptes Cuniculi mite: ivermectin can be used both topically and subcutaneously at a dose of 200 mcgs/kg, as it is used for other mites, lice and fleas.

Keep in mind that the exact dose of ivermectin should be determined by your veterinarian. Your veterinarian will consider your guinea pig's age and weight, as well as any other important factors.

Sarcoptes mange is one of the most common diseases in guinea pigs. The disease poses a serious threat to the health of the guinea pig. If you want to learn more about mange in guinea pigs, do not miss this other article where we explain the causes, symptoms, and treatment of guinea pig mange.

Contraindications of ivermectin in guinea pigs

Ivermectin should not be used in guinea pigs that are allergic to this active ingredient, in which the nervous system is impaired, or in guinea pigs that are only a few days old because they are not fully developed. Likewise, it should not be used in conjunction with other drugs that affect the nervous system.

Side effects of ivermectin in guinea pigs

One of the most attractive features of Ivermectin is how rare side effects are. Despite the fact that in very high doses it can cause depression of the guinea pig central nervous system, which can be fatal, this compound is safe because mammals, unlike parasites, lack the chloride channels that are activated by glutamate. Because macrocyclic lactones such as ivermectin have low affinity for other neurotransmitter-activated chloride channels and do not readily cross the blood-brain barrier, they have a high margin of safety in guinea pigs.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Ivermectin for Guinea Pigs - Dosage, Uses and Side Effects, we recommend you visit our Medicine category.

  • Cuniculture Bulletin, ISSN 1696-6074 - 20061002. Properties of ivermectin in rabbits and guinea pigs. Available at: file:///C:/Users/usuario/Downloads/Dialnet-PropiedadesDeLaIvermectinaEnLosConejosYCobayos-2869072.pdf
  • Avepa, continuing education. (2012). The essential small mammal clinic for general practitioners. Available at:
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Ivermectin for Guinea Pigs - Dosage, Uses and Side Effects