Parasitic diseases

Lice in Guinea Pigs - Symptoms and Treatment

Cristina Pascual
By Cristina Pascual, Veterinaria. Updated: January 29, 2024
Lice in Guinea Pigs - Symptoms and Treatment

Dermatologic pathologies are one of the main reasons for consultation in guinea pigs, with ectoparasites (external parasites) being the main cause of these pathologies. Guinea pigs are frequently infested with lice, which are ectoparasites. Generally, infested guinea pigs remain asymptomatic, although in some cases they can develop parasitic skin disorders.

This article on AnimalWised discusses the symptoms, treatment, and prevention of lice in guinea pigs.

You may also be interested in: Mange in Guinea Pigs - Symptoms & Treatment
  1. Symptoms of lice in guinea pigs
  2. How are guinea pigs infected with lice?
  3. Diagnosis of lice in guinea pigs
  4. Treatment of lice in guinea pigs
  5. How to prevent lice in guinea pigs?
  6. Other external parasites in guinea pigs

Symptoms of lice in guinea pigs

Parasitic diseases in guinea pigs are characterized by their slow and insidious onset, so they often go unnoticed by their owners. Typically, guinea pigs are subject to insidious parasitic infections, which they adapt to, so that they remain seemingly healthy and exhibit no signs of disease.

However, any situation in which the guinea pig's immune system is suppressed (such as stress, pregnancy, poor hygiene, environmental or dietary changes, nutritional deficiencies, etc.) causes the proliferation of ectoparasites, which results in the appearance of skin diseases. Below are examples of what you can observe in infested guinea pigs:

  • Skin lesions: include both primary lesions caused by the parasite itself (alopecia, scabbing or peeling) and secondary lesions caused by excessive scratching (sores and scabs).

  • Abnormal behavior: such as excessive scratching (due to itching or pruritus) or vocalizations.

  • Weight loss: the stress caused by severe itching may cause animals to lose weight. In the case of infested young guinea pigs, they can stop growing and gaining weight.

The two species of lice that commonly parasitize guinea pigs are Gliricola porcelli and Gyropus ovalis. Both are chewing lice that belong to the order Mallophaga. This type of louse feeds on the superficial layers of the skin, abrasions, scabs, and blood clots. As a result of their feeding, they can produce lice:

  • Primary lesions: Alopecia, scaling and scabbing.

  • Irritation: triggers intense itching, to which the animal responds by scratching or even biting to relieve the itching.

  • Secondary lesions: Sores and scabs.

How are guinea pigs infected with lice?

The transmission of lice in guinea pigs can occur in two ways:

  1. By direct contact with other infested guinea pigs.

  2. Indirectly through food, contaminated material (e.g. bedding) or infectious material (e.g. clothing or shoes).

Diagnosis of lice in guinea pigs

The diagnosis of lice infestation in guinea pigs is based on the following points:

  • Clinical history: prior to examination, your veterinarian will ask you about any changes in your guinea pig's behavior (e.g., excessive scratching or vocalizations), the presence of lesions, and the development of these lesions, if any. In cases of suspected ectoparasite infestation, the veterinarian will also inquire as to any possible cause (introduction of new guinea pigs, change in bedding material, etc.).

  • Complete examination: during the examination, the veterinarian will pay attention to detect lesions that indicate the presence of lice. These lesions can be primary (caused by the parasite itself) or secondary (caused by excessive scratching).

  • Direct Observation: guinea pig lice can be observed directly by examining the hair on the animal's back, especially the lower back and head. However, if the infestation is severe, the lice may be found all over the body.

  • Trichogram and observation under the microscope: to determine whether eggs are adhering to a hair sample (trichogram), the sample is observed directly under a microscope.

Treatment of lice in guinea pigs

As we have already mentioned, parasites are associated with immunosuppression problems in most cases. Therefore, one of the main goals of treatment must be to correct the cause of the immunosuppression (stress, diet, environment, etc.). It is key to ensure guinea pigs get vitamin C on a daily basis, particularly in the case of sick animals, because their needs are greater.

Following elimination of the cause of immunosuppression, we must consider how to eradicate lice from guinea pigs. To do this, the following steps must be taken:

  • Etiological treatment: Macrocyclic lactones such as ivermectin or selamectin are typically used because of their efficacy and low side effects. Ivermectin is administered orally, while selamectin is applied topically. It is also possible to inject these drugs subcutaneously, but this route should be avoided since it can cause severe pain and necrosis at the injection site. Bromocyclen is an alternative to macrocyclic lactones, and it is particularly effective against lice. It can be used in powder form or as a dip.

  • Anti-inflammatory treatment: it is not necessary in all cases of ectoparasitosis caused by lice, but it is necessary in cases of severe itching or inflammation associated with dermatopathy. NSAIDs (non-steroidal anti-inflammatory drugs) such as meloxicam should be used, but the use of corticosteroids is not recommended because of the adverse effects they cause in guinea pigs.

  • Treatment of pruritus: in animals with very severe pruritus (itching), diazepam may be added to the treatment to reduce the stress caused by the pruritus.

Since this parasite is highly contagious, if you have more than one guinea pig, you need to administer the antiparasitic treatment to all of them. Furthermore, it is important to clean and disinfect the environment to prevent reinfestation.

As we mentioned earlier, vitamin C is vital for guinea pigs because they cannot synthesize it in their bodies. Read on to learn more about the importance of vitamin C in guinea pigs.

How to prevent lice in guinea pigs?

In order to prevent lice infestation in guinea pigs, two important steps must be taken:

  • Quarantine: As we add a new guinea pig to the group, it is vital that we keep the animal separate from the other animals during the quarantine period. During this time, it is recommended to deworm the animal externally so that it will be free of external parasites when it is added to the group.

  • External deworming: Routine deworming prevents guinea pigs from becoming infected with parasites. Preventive treatment must always be done with special products for rodents, as antiparasitics intended for dogs and cats can be fatal to guinea pigs. So, if you plan on giving your guinea pig an antiparasitic, make sure it is prescribed by a veterinarian who specializes in roedents.

Even if your guinea pig has lice, you can be sure that they will not be transmitted to humans or other pets. The lice that commonly infest guinea pigs are very host-specific parasites. Their legs are designed to adapt exclusively to the hair of the species they parasitize, which means that interspecies transmission is impossible.

When you notice that your guinea pig is acting strangely, it may be due to lice or other diseases. Read on to see if your guinea pig is ill.

Other external parasites in guinea pigs

Guinea pigs can also be infested by other external parasites, such as mange-producing mites or fleas and ticks, especially if they live with dogs, cats, or other carriers since these ectoparasites are not species-specific.

Mites in guinea pigs

Trixacarus caviae and Chirodiscoides caviae, which produce scabies, are the two mite species that affect Guinea pigs.

  • Trixacarus caviae: This is a scabies mite specific to guinea pigs and is potentially zoonotic, meaning it can be transmitted to humans and cause dermatitis and itching. It is a burrowing mite that creates tunnels in the stratum corneum of the skin where it lays its eggs. The presence of these mites triggers a cell-based immune response that results in very severe pruritus (itching), erythema (redness of the skin), alopecia, hyperkeratosis, and secondary bacterial or fungal dermatitis. Injuries from scratching, such as sores and scabs, are also common. The animal may also experience anorexia, convulsions, or even death in severe cases. Because it is a burrowing mite, identification of the parasite under the microscope requires deep scratching.

  • Chirodiscoides caviae: Although not a burrowing mite, it lives in the hair of guinea pigs and feeds on scales and lays eggs. Usually its presence is asymptomatic, although poor hair, itching, and erythema may be observed in massive infestations.

Much less frequently, mite infestations that are not specific to guinea pigs occur, such as:

  • Cheyletiella parasitovorax: Rabbits are commonly infected with this mite, although it can occur in guinea pigs living with other carriers. The mite produces itching and a large amount of white scales on the infected area.

  • Demodex caviae: occurs very rarely in guinea pigs and is always associated with situations of immunosuppression.

Learn more about scabies in guinea pigs: symptoms and treatment in this other AnimalWised post.

Fleas and ticks in guinea pigs

Guinea pigs can be infested with dog fleas ( Ctenocephalides canis) and cat fleas ( Ctenocephalides canis). In these cases, a poor-looking coat, areas of hair loss, itching, and scabs may be observed, especially on the face and ears.

Continue reading this article if you want to learn more about the diagnosis and treatment of mange 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 Lice in Guinea Pigs - Symptoms and Treatment, we recommend you visit our Parasitic diseases category.

  • Moya, A., Henriques, CA, Ramos, M. (2018). Parasitic dermatopathies in the domestic guinea pig (Cavia porcellus). Argus; 198:96-97
  • Robles, K., Chavez, A. (2012). Evaluation of external parasitosis in guinea pigs (cavia porcellus) of commercial family breeding. National University of San Marcos, School of Veterinary Medicine.
  • White, SD, Sánchez-Migallon, D., Murphy, JP, Hawkins, MG (2016). Skin diseases in companion guinea pigs (Cavia porcellus): a retrospective study of 293 cases seen at the Veterinary Medical Teaching Hospital, University of California at Davis. Veterinary Dermatology; 27(5):395
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Lice in Guinea Pigs - Symptoms and Treatment