Ivermectin is a macrocyclic lactone used for the treatment of external parasites in many mammals. It is especially useful to eliminate small parasites of guinea pigs, that is, fleas, lice and mites, especially with the latter because they are the most frequent and with the most striking symptoms. Among all, the Trixacarus scabei mite should be highlighted as it is the one that causes the most damage to affected guinea pigs, causing skin lesions that can become infected, alopecia, redness, skin weakness, secondary lesions and even neurological signs such as seizures. In addition to being effective, it is quite safe in these small mammals, since the mechanism of action targets specific channels found within the muscle and nerve cells of invertebrates, not mammals.
Continue reading this article on our site to learn more about the uses of ivermectin for guinea pigs, its dosage and side effects.
What is ivermectin?
Ivermectin is a endectocide, that is, a drug indicated to treat and prevent external and internal parasites in various animal species, including the 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. Glutamate is a neurotransmitter, considered the main activator of the central nervous system, and is released by glial 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.
What is ivermectin used for in guinea pigs?
As internal parasites are extremely rare in guinea pigs, ivermectin in this species is used for the treatment of external parasites as mites, pugas and lice. Of these, the most important are mites, the main ones being the following:
- Trixacarus scabei: produces more serious symptoms, with itching, alopecia, self-traumatism that can induce secondary infections, reddening of the skin, papules, vesicles, scaling, weakness and behavioral changes. When the parasitosis is chronic, it produces a picture of thickening of the outer layer of the skin (hyperkeratosis) and can even lead to more serious pictures with seizures.
- Chirodiscoides caviae: it is found in the hair and is usually asymptomatic, so it does not cause clinical signs or lesions in the guinea pig if the immune system is fine and not immunosuppressed, as in the cases of pregnant females, stress or poor environmental and handling conditions.
- Psoroptes cuniculi: produces large crusts in the ear canal that can completely block it.
- Cheyletiella parasitivorax or “walking dandruff”: produces extensive flaking, especially on the back of the guinea pig.
Other mites that can affect these animals to a lesser extent are the ear mite, which is responsible for guinea pig notoedral mange (Notoedres muris), and sarcoptic mange (Sarcoptes scabei). In this other article we talk in depth about Mange in guinea pigs.
In addition to ivermectin, selamectin can also be used for these parasites and, if they are refractory to treatment, doramectin until no parasites are found in 3 skin scrapings.
Ivermectin dose for guinea pigs
The dose of ivermectin for guinea pigs depends on the parasite to be treated. In general terms, the dose of ivermectin will be as follows:
- To treat Trixacarus scabei mite: 0.2 ml of ivermectin subcutaneously in adult guinea pigs and 0.1 ml in young guinea pigs.
- To treat the Chirodiscoides caviae mite: topical ivermectin (in cream format at a dose of 0.5 mg/kg).
- To treat the Psoroptes cuniculi mite: it can be used both topically and subcutaneously at a dose of 200 mcgs/kg, the same as for other mites, lice and fleas.
Contraindications of ivermectin in guinea pigs
Ivermectin should not be used in guinea pigs allergic to this active ingredient, in those with nervous system involvement or in guinea pigs of few days old due to complete lack of development. Likewise, it should not be used if other drugs with action on the nervous system are also being used.
Side effects of ivermectin in guinea pigs
Although in very high doses can cause central nervous system depressionfrom the guinea pig, which can be fatal, this compound is safe because, unlike parasites, mammals 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.
If you live with one of these adorable animals, don't hesitate to consult this other article on Guinea pig care to offer them the best quality of life.
