Help! My Guinea Pig Has Mites

Updated November 28, 2020

The most common health problem in guinea pigs is itching and scratching caused by mites. It’s a simple problem with a simple solution. However, as you’ll see, there’s also a lot of rubbish being said.

The first myth is that it’s always mites. Guinea pigs actually get three common skin problems.

Causes Of Hair Loss

guinea pig lice
Guinea pig lice
  • Mites
  • Lice
  • Ringworm

Of the three, lice are the least serious. They cause obvious flaking and dandruff, but less itch or hair loss. They can (just) be seen with the naked eye.

Ringworm is a fungal infection that causes extensive hair loss, but is also less itchy and a lot rarer. Of the three causes, only ringworm can cause serious infections in people. I’ve seen some terrible cases, so if you start getting sores too, it’s time to see a doctor!

Hair loss in older females can also be caused by a hormonal imbalance due to ovarian cysts. Then there’s the normal hairless patch behind their ears that often gets confused with mites. In both cases, the affected skin appears smooth and healthy.

What Mites Look Like

Guinea pig mites (Trixacarus caviae) are very similar to the human scabies mite. They are microscopic, and burrow in the skin. Signs of early mite problems include:

  1. Itching & scratching
  2. Biting the body
  3. Hair loss
  4. Scaly or crusty skin

Then, if the problem isn’t treated, the damaged skin begins to break open. This leads to bleeding sores, twitching, weight loss and seizures in severe cases. Death can even ensue if enough of the skin has been damaged.

Where Mites Come From

There’s a persistent myth that mites come from hay, straw or bedding. The idea came about to explain why mites seem to come out of nowhere. The truth is that mites are spread by healthy carriers.

Most of the cases I see start after a new guinea pig is introduced. Then one or another of the existing cavies starts scratching. It’s also possible for a hidden infestation to break out during times of illness or stress. A good example of this is pregnancy.

How To Treat Mites In Guinea Pigs

Sprays and lotions are a waste of time and money in my opinion. Unless the drug gets in the bloodstream it doesn’t seem to get all of the mites.

The mainstay of treatment is a systemic anti-parasite drug. Here in Australia we use ivermectin as an injection, which also works well for lice. Two doses are given 10 to 14 days apart; the first kills the adult mites, the second kills the hatched eggs before they lay eggs of their own.

It’s important to treat every guinea pig, whether affected or not. If you are taking one pig to the vet, it’s therefore best to take them all. Most vets will charge just one visit fee to do the lot.

What I never do is ask owners to clean, sterilise or throw away cages and bedding. I completely reject the idea that the mites can live far from guinea pigs. I have treated thousands of cavies without ever having a treatment failure. All I ask is a regular spring clean and change the litter.

So if you suspect mites, don’t despair. Since the development of ivermectin, parasitic diseases are the best sorts of skin problem to have: curable ones! So see your vet and it’ll be sorted in no time.

Have something to add? Comments (if open) will appear within 24 hours.
By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. Meet his team here. The information provided here is not intended to be used as a substitute for going to the vet. If your pet is unwell, please seek veterinary attention.

11 Replies to “Help! My Guinea Pig Has Mites”

  1. Hi,
    My 4y old gp has mite problem. He and his buddy were treated with ivermectin today. But is there anything i could use to ease the itching before ivermectin starts working? Thank you 🙂

    1. Hi Ana. I don’t think there is anything safe enough but you could try a cool bath if you are careful to keep the water out of their mouth and nose, and they are tolerant to handling.

      1. I didnt think u could bathe the guinea pigs til after the treatment is done. 10 – 14 days apart from 1st dose, thats when the adults die & new babys appear. Cause mites burrow under the skin when wet & causes seizures. So they should hold off bathing til after doing the 2 lots of drops over the 14 days period. Then using melesab wash & leaving on for 10mins. They could use the cream canestan in meantime to help the skin.

  2. Hi Andrew,

    Thanks so much for your article. I recently brought my two 2year-old gp’s inside for the winter (we live in the uk). The stress of the move seems to have caused an outbreak of mites in one but not (as yet) the other. When I brought them inside a fortnight ago, I bathed them and applied my usual topical anti mite serum from the pet shop. A week later, and one had lost all of its hair from its bottom up, leaving only hair around the head and neck. Skin is scaly with white bits all over that look like dead skin. I took them to the vets, who confirmed mites and gave me more topical mite serum for the back of their necks. I treated a week ago, cleaned cage thoroughly (hadn’t seen your article then) but she is still scratching so much. Today, two weeks after the first treatment and a week after the second, she’s scratched herself that much that she has nasty, open, bleeding sores all over one side of her back, near to the bottom. Should the treatment have worked to ease the itching by now? Should I go to a different vet, incase it has been misdiagnosed? I don’t know what to do. Thank you

    1. Hi Helen. That’s certainly sounds like mites, and I would’ve thought the treatment would be working by now. I definitely would either get back in touch with your Vet or seek a second opinion.

  3. Hay is a source of mite infestation.
    In my home town a large number of people caught hay mite from a home and leisure show that used infested hay as seating.
    I was contracted to assist in set up of the show and I moved about 40 bales myself and became infected.
    Please consider the advice you provide people.

    1. Hi Michael. I understand your position as it is the folk wisdom, but the article is intended to debunk this myth. Never in my career have I seen reinfestation except by the introduction of new (carrier) cavies, and I have done this thousands of times by now. It would be very hard to observe the same findings in large groups but it’s easy to see with smaller numbers of isolated household pets.

  4. Where could a guinea pig get mites then if not through the introduction of a new guinea pig? Could wild birds bring mites into a backyard and somehow the guinea pigs get them?
    I’d love to know the source of our current outbreak. We use wood shavings for bedding and bagged hay. Could any of those be the source?

    1. Hi Teagan. The mites are very specific to guinea pigs, and so we think that an outbreak can also occur when a carrier guinea pig has a drop in immunity. Then the mites can cause symptoms and be spread to the other pigs in the group.

  5. Hello

    Thanks for your very informative article. I suspect we may have a mite problem with severe hair loss on one of the gp’s.

    We have 4 GP’s, 2 each in 2 seperate cages. The cages are on the grass in the back yard and distanced from each other. I.e. the occupants of one cage don’t mix with the occupants of the other cage. Is it ok to just take the two from the infested cage to the Vet do you think?

    Many thanks


    1. Hi Steven. Check with your vets as they might (like I do) only charge one visit for the whole lot if it’s all for the same thing. Otherwise you are probably right in just getting the two in-contact animals treated as long as you enforce the quarantine afterwards as well.

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