My two male guinea pigs have been diagnosed with static mice (chirodiscoides caviae) since october last year. I have been to the vet numerous of times who first advised giving them ivermectin drops every 10 days for 3 doses in total. Then went back 2 weeks after last dose as I could still see them in the fur. The vet then gave me ivermectin drops to use at home every 2 weeks for 3 doses in total, the last dose was 2 weeks ago and they are still there. I've tried bathing them with pet shampoo and sprayed the cage with small rodent insect spray week. Has anyone experienced this before and can help? TIA.
Hi anad welcome
Sadly, a few strains of hay mites (or what you call static lice) can be very hard to get rid off.
- Firstly: Have you changed the hay brand/hay supplier? We have noticed a sharp rise in hay mite cases that are hard to get rid of since the introduction of imported hay brands that sell hay harvested on an industrial range with methods that churn up the soil a lot more than more small scale conventional methods. There is the risk of a re-infection through new hay batches if you haven't.
We usually don't see any problems with hay mites with forum members using smaller UK online suppliers with less invasive harvesting methods. The only time I had a piggy with them was from a freshly adopted arrival with a lowered immune system who had obviously been kept on imported hay previous to the surrender.
A Comprehensive Hay Guide for Guinea Pigs (incl. providers in several countries)
- Secondly: Invisible hay mites fix their tiny egg cases to hairs preferably at the bum end but spread all over the body in more advanced infestations. It is these egg cases that you can feel as tiny beads and that look like somebody has turned a pepper mill over the body that have lead to the (incorrect) name of 'static lice'. The mites themselves live off debris on the skin and hairs. That is why ivermectin only is not always effective. What product have you been prescribed?
- Thirdly: Pet shop insecticidal shampoo is not exactly efficient and cannot touch any eggs. it is unfortunately wasted money like most pet shop products. Keep in mind that the shops are not allowed to sell vet strength medication, just preventatitive low dosed products.
What I would recommend:
- Give your piggies a short haircut in all affected areas to get rid of as many eggs as you can. These are all future mites that you do not have to kill chemically and that cannot make any more eggs. Mechanical removal is the most unglamorous but often a very efficient method of reducing the size of an infestation problem. The hair will grow back, even in short-haired piggies.
- Give your piggies a bath with lice'n'easy shampoo from Gorgeous Guineas every 4 days for at least 3-4 times.
Problem Solving Shampoos
(Lice'n'easy on its own is not necessarily effective on its own in our forum experience but the combination with ivermectin has often done the trick in persistent cases).
- While your piggies are drying off, deep clean the cage with F10 or another vet grade disinfectant. And throw away your current hay so no new hay mites can be introduced from the outside!
- Waiting 48 hours in between any topical (i.e. on the skin treatment) to allow the previous application to be fully absorbed into the skin, you also start another course of ivermectin at the product specific interval. If you are a UK resident, we recommend xeno 50 or 450, depending on the weight of your piggies. Do another 3 rounds of that.
- Do another deep clean of the cage at the end of treatment.
I hope that this 3 pronged approach will work for you. If in any doubt, please consult with your vet!
If this doesn't work, your vet may try a course of stronghold injections. They are based on the active ingredient selamectin. My Nye had them for his own hay mite infestions and it did the trick, despite his weaker immune system.
