Lice in Rats

Updated Sep. 8, 2023
Domestic rats

In This Article


What are Lice in Rats?

Lice are tiny insects that live on the skin of animals, often within their fur or hair, that feed on blood. The most common type of lice in rats is Polyplax spinulosa, also known as a sucking louse. While lice are uncommon in pet rats, they are a common issue for laboratory and wild settings and more common in pet rats who are stressed, immunocompromised, or seniors.

Symptoms of Lice in Rats

Signs of lice in rats include:

  • Itching

  • Restlessness

  • Hair loss

  • Inflamed red skin

  • Weakness

  • Anemia

  • Self-trauma/scratches/scabs

Causes of Lice in Rats

Lice are tiny blood sucking insects that live on the skin of animals and are generally species specific. Lice are spread to rats by direct contact with other infected rats and are more likely to spread in stressed, immunocompromised, sick, or senior pets.

How Veterinarians Diagnose Lice in Rats

Lice, unlike most other ectoparasites, can be seen with the naked eye. Your vet will likely perform a skin scrape, which helps transfer the lice from the skin onto a slide to look at under the microscope for definitive identification.

Lice suck blood and can cause anemia over time. As part of their testing, your vet may collect a small blood sample to check your rat for anemia.

Treatment of Lice in Rats

Lice are typically treated through either topical application of antiparasiticides such as Revolution or injections of medications such as ivermectin by your vet. In some cases, your vet may also advise you to give medicated baths.

Treatment for anemia revolves around controlling the lice quickly, allowing the rat’s body to correct the red blood cell deficit over time.

Recovery and Management of Lice in Rats

It is critical to clean and disinfect your rat’s cage and any objects or bedding and then maintain a clean environment for them while they recover. Rat lungs are very sensitive so be sure not to use anything with a fragrance and try to keep to diluted bleach or white vinegar for disinfecting.

Lice are more likely to create a problem for a rat if other ectoparasites are present. Lice can also make it more likely for rats to pick up other parasites, especially if they’re weakened to the point of being anemic. It is important to note any new lesions and report them to your vet in case they develop other infections or ectoparasites.

Rats pick up lice from being directly exposed to other infected rats or contaminated bedding and can be more likely in cases of poor care. To prevent a lice infestation, be sure not to let your rats interact with rats outside their colony and keep their cages and bedding clean.

Lice are highly contagious and by time of diagnosis it is likely that all rats sharing a cage will be infected. If your vet believes only certain rats in a group are currently infected, you may need to quarantine affected rats from unaffected rats.

Lice in Rats FAQs

Can humans get lice from rats?

Rat lice are species specific. While owners handling rats with significant infestations may notice some small bites, the lice cannot infect or live on humans.

What does lice look on rats?

Rats with lice will often be restless and itchy with hair loss and scratches of the skin, especially the back of the neck. They may also seem lethargic if their infection is bad enough and they’re anemic.

How did my rats get lice?

Rats need to come in direct contact with another rat with lice or contaminated bedding to get lice themselves. In a home setting this can be from interacting with someone else’s rat or having wild rats present in the house.

What kind of lice do rats get?

Rats get sucking lice. These suck and live off blood and over time can cause the infected rat to become anemic. Swift identification and treatment through your vet is important to treat lice on rats.


  1. Disorders and Diseases of Rats - All Other Pets. Merck Veterinary Manual.

  2. Johnson, D. H. Parasites in Your Pocket (Pets): Companion Mammal Parasitology. Veterinary Information Network. 2019.

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Maria Zayas, DVM


Maria Zayas, DVM


Dr. Zayas has practiced small animal and exotic medicine all over the United States and currently lives in Colorado with her 3 dogs, 1 cat,...

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