Q: We adopted a guinea pig in April 2010. He’s roughly 4 years old. He started scratching, and we found out he had mites. We took him to the specialist vet and treated him in April (one dose). The mites came back, and we got the medicine for him again in June. That time we gave him half the amount in the package (it was more than needed for his weight). We gave the second half a week later. In September, he got mites again. He’s very irritable, biting or running away if he thinks you are going to pet him. His hair comes out in chunks if you give it the lightest pinch. Most of the problem is localized on his back, the area above his hind legs. His tummy is fine and around his face appears OK. His ears are a little scaly, like dry skin. Could he have ear mites and we aren’t treating the right area? What else should we do? He’s not losing weight at this point and has a healthy appetite.
A: Mites are a common problem in guinea pigs but not so easy to treat. Two key factors affect treating mites in guinea pigs. The first is to use an effective protocol of an anti-parasiticide that is safe for guinea pigs and the second is to effectively treating the guinea pig’s environment.
Guinea pigs can be very sensitive to certain medications and products used in the environment — the wrong combination can kill guinea pigs. The effective medication used on guinea pigs is usually used as a “spot-on” treatment put directly on the skin. To break the adult-larva-egg cycle, it is important to re-treat again in about 10 days. Some of the more heavy infestations require a third treatment.
Mite species can also live in the environment or have eggs in the environment. If the area that the guinea pig lives in is not properly treated, mites will come back onto your guinea pig.
Because some of the environmental treatments are dangerous to guinea pigs, I recommend removing and throwing out any material that it is feasible to replace. I tell owners to vacuum the guinea pig’s area and use soap and water to clean whatever cannot be thrown out. Those are safe ways to clean the environment.
If your guinea pig is treated effectively and the environment is properly disinfected from mites and their eggs, your guinea pig should then be mite-free and feel much better.